Functional Foods · Fermented food
Tempeh
Glycine max (fermented with Rhizopus) · also called Tempe, fermented soybean cake
Tempeh is a firm cake of soybeans held together by a mould, eaten as a plant protein food. Raw tempeh has about 20 g of protein per 100 g. Human research on tempeh itself is small: one trial found its calcium absorbed about as well as milk, and fermented soy foods as a group gave small changes in blood sugar and cholesterol. The main cautions are soy allergy, MAOI antidepressants and histamine or tyramine sensitivity.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Tempeh
Tempeh is a firm cake of cooked soybeans bound together by a mould, eaten as a protein food. It is a food, not a proven remedy: the human studies on tempeh are small, and the blood sugar findings come from animals.
What it is
Tempeh is a traditional Indonesian fermented soybean product. A 2026 scoping review of 36 articles says Rhizopus mould species and lactic acid bacteria drive the fermentation. Tempeh can also be made from other beans and grains; this page covers soybean tempeh.
USDA data for raw tempeh, per 100 g: 192 kcal, 20.29 g protein, 10.8 g fat, 7.64 g carbohydrate, 111 mg calcium, 2.7 mg iron, 266 mg phosphorus, 1.3 mg manganese, 0.56 mg copper and 9 mg sodium. USDA's 1 cup portion (166 g) works out to about 319 kcal and 33.7 g protein. Cooked tempeh is a separate USDA item with slightly different values.
Calcium and iron: what was tested
In one randomised crossover trial, 20 postmenopausal Malay women absorbed 36.9% of the calcium in a tempeh meal and 34.3% from milk, not a significant difference. Tempeh had less calcium per serving, so the authors say four servings would be needed to match the absorbed calcium of a glass of milk. The trial tempeh had about 63 mg calcium per 100 g, lower than the USDA raw value, so check labels.
In a trial of 252 pregnant women in Indonesia, a weekly food package of tempeh, fruit and a little meat did not change iron status overall. Falls in iron markers were smaller in women who were iron-deficient at the start, but these results were borderline, and tempeh was not tested alone.
What the research shows
Human research on tempeh itself is small. The strongest pooled result is for fermented soy foods as a group: 15 trials found small drops in fasting glucose, total cholesterol, waist size and BMI. The abstract does not say how many used tempeh. A 2026 umbrella review concluded that soy foods are more beneficial than harmful overall but that the benefits of fermented soy products were inconclusive.
A 13-person crossover study found a tempeh breakfast lowered the hunger hormone acyl-ghrelin by 35% at 30 minutes, but people did not report feeling less hungry. Another small study showed isoflavones from tempeh are absorbed.
A 2026 review of lab and animal studies found soybean tempeh lowered blood glucose in diabetic animals. That is not evidence for people. No human trial of tempeh and gut health was read.
Food versus supplements
The calcium, isoflavone absorption and appetite findings are for tempeh eaten as food. The blood sugar, cholesterol and waist findings are for fermented soy foods as a group, and the blood sugar animal findings are for tempeh in animals. Soy protein powders and isoflavone supplements are different products from tempeh.
At a glance
Traditional uses history, not proof
- Eaten as a staple food in Indonesia and now in many countries
- Long use as food is not proof that it treats any condition
Studied for research
- Protein, copper, manganese and other nutrients, high certainty for the nutrient content
- Calcium absorption, low certainty (one small trial)
- Iron status in pregnancy, very-low certainty (tempeh given with fruit and meat)
- Blood sugar, cholesterol and waist size, mixed (fermented soy foods in general)
- Appetite hormones after a meal, very-low certainty
- Isoflavone absorption, low certainty (a marker, not a health outcome)
- Blood sugar in diabetic animals, insufficient (animal and lab only)
- Gut health, insufficient (no human trial)
Main compounds
- Protein
- Copper and manganese
- Calcium and iron
- Soy isoflavones (daidzein, genistein)
- Short peptides and GABA (lab findings)
- Biogenic amines (histamine, tyramine)
Common forms
- Raw tempeh and cooked tempeh as food (both USDA items read)
- Soybean tempeh is the form covered; tempeh made from other beans or grains was not reviewed
- Flavoured or marinated tempeh nutrient values were not read
- Isoflavone and soy protein supplements are different products and are not covered
Research links: 2025 pooled analysis: fermented soy and metabolic markers (15 trials) · 2010 trial: calcium from tempeh compared with milk · 2026 review: tempeh and diabetes (animal and lab studies) · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Glycine max (L.) Merr. (the soybean, usually the main ingredient)
- Naming authority
- (L.) Merr. (GBIF accepted). Tempeh itself is a food, not a species; the mould Rhizopus oligosporus is listed by GBIF as a synonym of Rhizopus microsporus.
- Common names
- Tempeh (English); Tempe (Indonesian); Fermented soybean cake (English); Tempeh (Spanish)
- Family or group
- Fabaceae (the legume family) for the soybean, as given by GBIF. Tempeh is a processed food, not a plant.
- Classification
- Plantae > Tracheophyta > Magnoliopsida > Fabales > Fabaceae > Glycine > Glycine max
- Native range
- Not verified from a source read.
- Habitat
- Not verified from a source read.
- What it looks like
- Fruit: Tempeh is a firm cake of soybeans bound together by mould. USDA gives a household portion of 1 cup (166 g) for raw tempeh.
- Cultivation
- Not verified from a source read.
- Harvest and processing
- A 2026 scoping review describes tempeh as a traditional Indonesian fermented soybean product in which Rhizopus species and associated lactic acid bacteria drive the fermentation. Tempeh can also be made from other beans and grains. The detailed making process was not read from a source, so it is not described here.
- Look-alikes and adulterants
- Name: Tofu; Note: Unfermented soybean curd with its own page; it differs in nutrients and fermentation.; Name: Natto and miso; Note: Other fermented soy foods with their own pages, made with different microbes.; Name: Tempe bongkrek; Note: A coconut-based tempeh-type food linked to bongkrekic acid poisoning; not the same as soybean tempeh.; Name: Tempeh from other beans or grains; Note: Studies of these should not be read as evidence for soybean tempeh.
Photographs
What is inside, and how it may work
What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Protein | protein | Cake of soybeans USDA: 20.29 g per 100 g (raw); 19.91 g (cooked) | Also the source of the soy allergen. 24 23 | Human data |
| Copper and manganese | mineral | Cake of soybeans USDA per 100 g raw: copper 0.56 mg, manganese 1.3 mg | Nutrients the body needs; no trial of tempeh for these was read. 24 | Human data |
| Calcium and iron | mineral | Cake of soybeans USDA per 100 g raw: calcium 111 mg, iron 2.7 mg; cooked: 96 mg and 2.13 mg | Calcium from a tempeh meal was absorbed about as well as from milk in one small study. 24 23 5 | Human data |
| Soy isoflavones (daidzein, genistein) and their forms | isoflavone | Cake of soybeans Not read for tempeh | Absorbed after eating tempeh (urinary levels higher than after milk). A scoping review says fermentation raises isoflavone aglycones. 6 18 | Human data |
| Short peptides and GABA | peptide and amino acid | Fermented soybeans Not read | Peptides with antioxidant and ACE-inhibitor activity and raised GABA and amino acids are described in the lab; no human effect shown. 18 | Lab |
| Biogenic amines (histamine, tyramine) | amine | Fermented soybeans Very variable; no tempeh amount read | Can raise blood pressure or cause headache in sensitive people or people on MAOIs. 11 13 | Human data |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Fermentation by Rhizopus and lactic acid bacteria | Phytase, amylase and protease genes | A 2026 scoping review of 36 articles describes enzymes, short peptides, GABA and isoflavone aglycones produced during fermentation. These are lab findings; the authors call for human studies. 18 | Lab |
| Blood glucose control (proposed) | alpha-amylase, alpha-glucosidase, AMPK | A review of lab and animal work proposes that tempeh blocks sugar-digesting enzymes and activates AMPK in diabetic animals. Not shown in people. 1 | Animal research |
| Amine formation in fermented foods | Monoamine oxidase (the enzyme MAOI drugs block) | Reviews explain that biogenic amines such as histamine and tyramine are made by microbes in fermented foods and vary with raw materials and processing. With an MAOI, tyramine can raise blood pressure. 13 11 4 | Lab |
Absorption, metabolism and elimination
- Absorption
- Calcium from a tempeh meal was absorbed at 36.9% versus 34.3% from milk in 20 postmenopausal women. Isoflavones from tempeh were detected in urine at levels well above those after milk.
- Distribution
- Not found.
- Metabolism
- Almost all women excreted equol after tempeh, but only one was classed as an equol producer.
- Elimination
- Not found.
- Bioavailability
- Established for calcium and isoflavones in the small studies read; not read for iron, protein or other nutrients from tempeh.
Isolated compounds versus whole extracts
The nutrient, calcium and isoflavone absorption and appetite findings are for tempeh as food. The blood sugar, cholesterol and waist findings are for fermented soy foods as a group. The blood sugar animal findings are for tempeh or tempeh from other substrates in animals. Soy isoflavone or protein supplements are different products and are not covered.
Nutritional composition
Nutrition from USDA FoodData Central (SR Legacy, April 2018 release; values read 2026-10-26 from a saved copy of the data feed). Raw tempeh (FDC 174272), per 100 g: 192 kcal, 20.29 g protein, 10.8 g fat (2.539 g saturated), 7.64 g carbohydrate, 111 mg calcium, 2.7 mg iron, 81 mg magnesium, 266 mg phosphorus, 412 mg potassium, 9 mg sodium, 1.14 mg zinc, 1.3 mg manganese, 0.56 mg copper, 0.358 mg riboflavin, 2.64 mg niacin, 0.08 micrograms vitamin B12. One USDA portion of 1 cup (166 g, the 100 g values multiplied by 1.66): about 319 kcal, 33.7 g protein, 17.9 g fat, 12.7 g carbohydrate, 184 mg calcium, 4.5 mg iron, 442 mg phosphorus, 684 mg potassium, 15 mg sodium, 0.93 mg copper, 2.2 mg manganese. Cooked tempeh (FDC 172467), per 100 g: 195 kcal, 19.91 g protein, 11.38 g fat, 7.62 g carbohydrate, 96 mg calcium, 2.13 mg iron, 77 mg magnesium, 253 mg phosphorus, 401 mg potassium, 14 mg sodium; USDA lists no household portion for it. The cooked item has slightly different values from the raw one, and brands, recipes and added ingredients differ, so check the label. Tempeh made from other beans or grains was not read.
1 high certainty1 mixed findings2 low certainty2 very low certainty2 not enough evidence
What was looked at
The 8 benefits and uses checked for Tempeh, each with how strong the evidence is. Tap one to open it.
- Protein, copper, manganese and other nutrients (nutrient content)High certainty
- Calcium absorption (compared with milk)Low certainty
- Iron status in pregnancy (tempeh with fruit and a little meat)Very low certainty
- Blood sugar, cholesterol and waist size (fermented soy foods in general)Mixed findings
- Appetite hormones after one mealVery low certainty
- Blood sugar (animal and lab studies only)Not enough evidence
- Isoflavone absorption (a marker)Low certainty
- Gut health and "probiotic" claimsNot enough evidence
Lab markers tracked in the studies
Fasting blood glucoseTotal cholesterolFerritin and haemoglobin (iron status)Acyl-ghrelin (hunger hormone)Urinary daidzein, genistein and equolFraction of calcium absorbed
What is Tempeh good for?
The main studied uses and how strong the human evidence is for each. Very few studies tested tempeh on its own; most results are small, and some are for fermented soy foods in general.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Protein, copper, manganese and other nutrients (nutrient content)
High certaintyRaw tempeh has 20.29 g of protein per 100 g by USDA data, with 1.3 mg of manganese and 0.56 mg of copper. One USDA cup (166 g) has about 33.7 g of protein. This describes the food, not a treatment.
2 studiesRaw and cooked tempeh from USDA tables. Tempeh made from other beans …
Studies, doses and limits
What the trials found
No trial was read showing that eating tempeh corrects a shortfall of any nutrient. USDA lists raw tempeh and cooked tempeh as separate items with slightly different values.
Results
Tempeh is a protein food and a source of several minerals on paper. How much the body takes up was tested only for calcium (see the next entry).
Effect sizes as reported
USDA, raw tempeh per 100 g: 192 kcal, protein 20.29 g, fat 10.8 g, carbohydrate 7.64 g, copper 0.56 mg, manganese 1.3 mg, phosphorus 266 mg, riboflavin 0.358 mg, iron 2.7 mg, calcium 111 mg, sodium 9 mg. Cooked tempeh per 100 g: protein 19.91 g, fat 11.38 g, calcium 96 mg, iron 2.13 mg, sodium 14 mg.
Why this rating
High that the food contains these nutrients (USDA data). Not tested as a treatment for any shortfall.
Form and dose studied
Raw and cooked tempeh from USDA tables. Tempeh made from other beans or grains, flavoured or marinated tempeh were not read.
Who was studied
General adult diet.
Limits
Nutrient facts from one USDA data release, not trials. Brands and recipes differ.
Why researchers looked
People eat tempeh as a plant protein food.
Traditional use
Tempeh is eaten as a food, mainly in Indonesia and now around the world. Long use as food is not proof that it treats any condition.
Proposed mechanism Nutrient database
These are nutrient amounts in the food, taken from USDA tables.
A proposed mechanism does not show that the effect happens in people.
Soy is a major food allergen; see the Safety tab.
Calcium absorption (compared with milk)
Low certaintyIn one small crossover trial of 20 postmenopausal women, the share of calcium absorbed from tempeh (36.9%) was not significantly different from milk (34.3%). Tempeh had less calcium per serving, so more of it was needed for the same amount.
2 studiesTempeh meal of 206 g in the trial (trial detail, not advice).
Studies, doses and limits
What the trials found
Twenty postmenopausal Malay women each had 130 mg of calcium from milk (114 g) and from a tempeh meal (206 g) in random order, one month apart. Absorption was 36.9 +/- 10.6% from tempeh and 34.3 +/- 8.6% from milk, not significantly different. The authors say four servings of tempeh would be needed to equal the absorbed calcium of a 4-ounce glass of milk.
Results
The calcium in tempeh was absorbed about as well as the calcium in milk in this small study.
Effect sizes as reported
Absorption 36.9% versus 34.3% (not significant).
Why this rating
Low: one small crossover trial in 20 postmenopausal Malay women, with absorption as the outcome, not bone strength or fractures. The abstract does not name the funder.
Form and dose studied
Tempeh meal of 206 g in the trial (trial detail, not advice).
Who was studied
Postmenopausal Malay women.
Limits
Very small, one population, absorption only. The trial tempeh had about 63 mg calcium per 100 g, lower than the USDA value for raw tempeh (111 mg per 100 g), so products differ.
Why researchers looked
Researchers wanted to know whether a non-dairy food can supply calcium that the body takes up, in people who eat little dairy.
Traditional use
Tempeh is eaten as a food, mainly in Indonesia and now around the world. Long use as food is not proof that it treats any condition.
Proposed mechanism Human trial
Not established. The trial measured how much calcium was absorbed using stable calcium isotopes.
A proposed mechanism does not show that the effect happens in people.
None specific beyond the soy cautions.
Iron status in pregnancy (tempeh with fruit and a little meat)
Very low certaintyIn a trial of 252 pregnant women in Indonesia, a weekly food package with tempeh, fruit and a little meat did not change iron status overall. Among women who were iron-deficient at the start, falls in iron markers were smaller, but the results were borderline.
1 studiesWeekly package: 600 g tempeh, 30 g meat, 350 g guava, 300 g papaya, 1…
Studies, doses and limits
What the trials found
Women were assigned by village to an optimised food package or no package. Iron markers fell over pregnancy in both groups and the average changes were similar. In iron-deficient women, the package group had smaller falls in haemoglobin (P = 0.058), ferritin (P = 0.046) and body iron (P = 0.073). Tempeh was given together with meat, guava, papaya and orange, so tempeh's own effect cannot be separated.
Results
No clear overall effect; a possible small benefit in a subgroup, with tempeh not tested alone.
Effect sizes as reported
Smaller falls in iron-deficient women: haemoglobin 1.02 g/l (95% CI 0.98 to 1.07), ferritin 1.42 ug/l (1.16 to 1.75), body iron 2.57 mg/kg (1.71 to 3.43).
Why this rating
Very low: the overall result was no difference, the benefit is a subgroup finding at the edge of significance, and the package mixed tempeh with meat and fruit.
Form and dose studied
Weekly package: 600 g tempeh, 30 g meat, 350 g guava, 300 g papaya, 100 g orange (trial detail, not advice).
Who was studied
Pregnant women in Indonesian villages.
Limits
Assigned by village, not by individual. Subgroup result. Funder not stated in the abstract.
Why researchers looked
Iron deficiency in pregnancy is common, and researchers asked whether a food-based package could help.
Traditional use
Tempeh is eaten as a food, mainly in Indonesia and now around the world. Long use as food is not proof that it treats any condition.
Proposed mechanism Not established
Not established. The authors point to iron-rich food and vitamin C-rich fruit.
A proposed mechanism does not show that the effect happens in people.
See Safety for pregnancy.
Blood sugar, cholesterol and waist size (fermented soy foods in general)
Mixed findingsA pooled analysis of 15 trials of fermented soy foods found small drops in fasting blood glucose (6.39 mg/dL), total cholesterol (5.0 mg/dL) and waist size (1.5 cm). The abstract does not say how many trials used tempeh, and a larger review called the benefits of fermented soy inconclusive.
2 studiesFermented soy foods of various kinds.
Studies, doses and limits
What the trials found
The 2025 pooled analysis of 15 randomised trials found small, statistically significant improvements in BMI (-0.14 kg/m2), waist (-1.50 cm), visceral fat, fasting glucose (-6.39 mg/dL) and total cholesterol (-5.0 mg/dL); other markers did not change significantly. A 2026 umbrella review concluded soy foods are more beneficial than harmful overall but said the benefits of fermented soy products were inconclusive and that some studies indicated possible adverse effects.
Results
Small changes in some markers for fermented soy foods as a group; tempeh on its own was not separated out.
Effect sizes as reported
Fasting glucose -6.39 mg/dL (95% CI -10.38 to -2.40); total cholesterol -5.0 mg/dL (-6.60 to -3.39); waist -1.50 cm (-2.94 to -0.07); BMI -0.14 kg/m2 (-0.28 to -0.01).
Why this rating
Mixed: small average changes, some barely above zero, in a group of different fermented soy foods, and an umbrella review that called benefits inconclusive. Not specific to tempeh.
Form and dose studied
Fermented soy foods of various kinds.
Who was studied
Adults in 15 trials; details not in the abstract.
Limits
Tempeh is not named in either abstract. The meta-analysis abstract gives no certainty rating.
Why researchers looked
Tempeh is one fermented soy food, and fermented soy has been tested for blood sugar and cholesterol.
Traditional use
Tempeh is eaten as a food, mainly in Indonesia and now around the world. Long use as food is not proof that it treats any condition.
Proposed mechanism Not established
Not shown for tempeh.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab.
Appetite hormones after one meal
Very low certaintyIn a very small crossover study of 13 young women with overweight or obesity, a tempeh breakfast lowered the hunger hormone acyl-ghrelin by 35% at 30 minutes compared with no change after a non-fermented soybean meal. People did not report feeling less hungry.
1 studiesTempeh breakfast of 307 kcal (trial detail, not advice).
Studies, doses and limits
What the trials found
Thirteen females aged 18 to 20 (BMI 25 to 30) ate a 307 kcal breakfast with tempeh or with non-fermented soybean in random order. Acyl-ghrelin fell 35% at 30 minutes after tempeh and stayed below baseline to 120 minutes. Insulin response was 30% greater and arginine 24% greater at 120 minutes. Subjective appetite did not differ.
Results
A hormone difference after one meal, with no difference in reported appetite.
Effect sizes as reported
Acyl-ghrelin -35% at 30 min (P < 0.05); insulin +30% and arginine +24% at 120 min versus non-fermented soybean.
Why this rating
Very low: 13 people, a single meal, hormone markers rather than weight or hunger, and no difference in reported appetite.
Form and dose studied
Tempeh breakfast of 307 kcal (trial detail, not advice).
Who was studied
Young Indonesian women with BMI 25 to 30.
Limits
Tiny sample, single meal, hormone markers only.
Why researchers looked
Researchers asked whether fermenting soy changes the body's hormone response to a meal.
Traditional use
Tempeh is eaten as a food, mainly in Indonesia and now around the world. Long use as food is not proof that it treats any condition.
Proposed mechanism Human trial
Not established. Insulin and arginine were also higher after the tempeh meal.
A proposed mechanism does not show that the effect happens in people.
None specific.
Blood sugar (animal and lab studies only)
Not enough evidenceA 2026 review of lab and animal studies found that soybean tempeh lowered blood glucose in diabetic animals. No human trial of tempeh for blood sugar is covered, so nothing is shown for people.
1 studiesSoybean tempeh and tempeh from other beans and grains, in animals and…
Studies, doses and limits
Results
Lower blood glucose in diabetic animals and lab effects on enzymes. Not shown in people.
Effect sizes as reported
No numbers in the abstract.
Why this rating
Insufficient: animal and lab evidence only; the review's own conclusion that tempeh is promising does not rest on human data.
Form and dose studied
Soybean tempeh and tempeh from other beans and grains, in animals and lab tests.
Who was studied
Diabetic animals and cell models.
Limits
Not human evidence. Non-soy tempeh results are not evidence for soybean tempeh.
Why researchers looked
Tempeh contains isoflavones, peptides and other compounds that change during fermentation, and these have been tested in animals.
Traditional use
Tempeh is eaten as a food, mainly in Indonesia and now around the world. Long use as food is not proof that it treats any condition.
Proposed mechanism In vitro and animal
The review proposes blocking sugar-digesting enzymes (alpha-amylase and alpha-glucosidase), AMPK activation, antioxidant effects and changes in gut microbes. These are lab and animal findings.
A proposed mechanism does not show that the effect happens in people.
None.
Isoflavone absorption (a marker)
Low certaintyAfter women ate 240 g of tempeh, their urine had far more daidzein, genistein and equol than after milk, so isoflavones from tempeh are absorbed. This shows exposure, not a health effect.
1 studies240 g tempeh (trial detail, not advice).
Studies, doses and limits
What the trials found
In the same small study of postmenopausal Malay women, urinary daidzein, genistein and equol were significantly higher after tempeh than after milk. Almost all women excreted equol, but only one could be classed as an equol producer.
Results
Isoflavones are absorbed from tempeh. No health result was measured.
Effect sizes as reported
Daidzein 47.06 vs 3.51 umol/h; genistein 33.27 vs 2.79 umol/h; equol 24.35 vs 0 umol/h (P < 0.05).
Why this rating
Low: a small study showing exposure only. Milk is a poor comparison because it has almost no isoflavones.
Form and dose studied
240 g tempeh (trial detail, not advice).
Who was studied
Postmenopausal Malay women.
Limits
Marker, not a health outcome. Small.
Why researchers looked
Isoflavones are estrogen-like plant compounds from soy, and researchers wanted to know whether the body takes them up from tempeh.
Traditional use
Tempeh is eaten as a food, mainly in Indonesia and now around the world. Long use as food is not proof that it treats any condition.
Proposed mechanism Human trial
The body absorbs soy isoflavones and gut microbes can convert daidzein to equol. Whether any of this affects health was not tested here.
A proposed mechanism does not show that the effect happens in people.
See Safety for soy and hormone-sensitive conditions.
Gut health and "probiotic" claims
Not enough evidenceNo trial of tempeh and gut health was read. Fermented foods are not the same as probiotics, and lab work shows tempeh carries many microbes and gene types, which does not show an effect in people.
3 studiesTempeh as eaten; how cooking changes live microbes was not read.
Studies, doses and limits
Results
Descriptions of what is in tempeh, with no human gut outcome.
Why this rating
Insufficient: no human trial; lab and gene studies only.
Form and dose studied
Tempeh as eaten; how cooking changes live microbes was not read.
Limits
Gene presence does not show amounts or effects.
Why researchers looked
Tempeh is a fermented food made with a mould and bacteria, so people ask whether it supports gut health.
Traditional use
Tempeh is eaten as a food, mainly in Indonesia and now around the world. Long use as food is not proof that it treats any condition.
Proposed mechanism Lab
Lab studies describe the microbes and compounds in tempeh. No human mechanism was shown.
A proposed mechanism does not show that the effect happens in people.
See Safety for histamine and tyramine in fermented foods.
Connections to the rest of health
How Tempeh connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
A. Wellness goals
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Preventive Wellness | High certainty | Protein, copper, manganese and other nutrients (nutrient content): Raw tempeh has 20.29 g of protein per 100 g by USDA data, with 1.3 mg of manganese and 0.56 mg of copper. One USDA cup (166 g) has about 33.7 g of protein. This describes the food, not a treatment. | 24 23 | |
| Bone Health | Low certainty | Calcium absorption (compared with milk): In one small crossover trial of 20 postmenopausal women, the share of calcium absorbed from tempeh (36.9%) was not significantly different from milk (34.3%). Tempeh had less calcium per serving, so more of it was needed for the same amount. | 5 24 | |
| Womens Wellness | Very low certainty | Iron status in pregnancy (tempeh with fruit and a little meat): In a trial of 252 pregnant women in Indonesia, a weekly food package with tempeh, fruit and a little meat did not change iron status overall. Among women who were iron-deficient at the start, falls in iron markers were smaller, but the results were borderline. | 16 | |
| Blood Sugar Balance | Mixed findings | Blood sugar, cholesterol and waist size (fermented soy foods in general): A pooled analysis of 15 trials of fermented soy foods found small drops in fasting blood glucose (6.39 mg/dL), total cholesterol (5.0 mg/dL) and waist size (1.5 cm). The abstract does not say how many trials used tempeh, and a larger review called the benefits of fermented soy inconclusive. | 9 7 | |
| Cholesterol Balance | Mixed findings | Blood sugar, cholesterol and waist size (fermented soy foods in general): A pooled analysis of 15 trials of fermented soy foods found small drops in fasting blood glucose (6.39 mg/dL), total cholesterol (5.0 mg/dL) and waist size (1.5 cm). The abstract does not say how many trials used tempeh, and a larger review called the benefits of fermented soy inconclusive. | 9 7 | |
| Weight Management | Mixed findings | Blood sugar, cholesterol and waist size (fermented soy foods in general): A pooled analysis of 15 trials of fermented soy foods found small drops in fasting blood glucose (6.39 mg/dL), total cholesterol (5.0 mg/dL) and waist size (1.5 cm). The abstract does not say how many trials used tempeh, and a larger review called the benefits of fermented soy inconclusive. Appetite hormones after one meal: In a very small crossover study of 13 young women with overweight or obesity, a tempeh breakfast lowered the hunger hormone acyl-ghrelin by 35% at 30 minutes compared with no change after a non-fermented soybean meal. People did not report feeling less hungry. | 9 7 12 | |
| Blood Sugar Balance | Not enough evidence | Blood sugar (animal and lab studies only): A 2026 review of lab and animal studies found that soybean tempeh lowered blood glucose in diabetic animals. No human trial of tempeh for blood sugar is covered, so nothing is shown for people. | 1 | |
| Menopause Support | Low certainty | Isoflavone absorption (a marker): After women ate 240 g of tempeh, their urine had far more daidzein, genistein and equol than after milk, so isoflavones from tempeh are absorbed. This shows exposure, not a health effect. | 6 | |
| Gut Health | Not enough evidence | Gut health and "probiotic" claims: No trial of tempeh and gut health was read. Fermented foods are not the same as probiotics, and lab work shows tempeh carries many microbes and gene types, which does not show an effect in people. | 10 15 18 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Musculoskeletal System | Biological association | High certainty | Studied for: Protein, copper, manganese and other nutrients (nutrient content) Studied for: Calcium absorption (compared with milk) | 24 23 5 |
| Reproductive System | Biological association | Very low certainty | Studied for: Iron status in pregnancy (tempeh with fruit and a little meat) Studied for: Isoflavone absorption (a marker) | 16 6 |
| Cardiovascular System | Biological association | Mixed findings | Studied for: Blood sugar, cholesterol and waist size (fermented soy foods in general) | 9 7 |
| Metabolism Weight | Biological association | Mixed findings | Studied for: Blood sugar, cholesterol and waist size (fermented soy foods in general) Studied for: Appetite hormones after one meal | 9 7 12 1 |
| Endocrine System | Biological association | Very low certainty | Studied for: Appetite hormones after one meal Studied for: Blood sugar (animal and lab studies only) | 12 1 |
| Digestive System | Biological association | Not enough evidence | Studied for: Gut health and "probiotic" claims | 10 15 18 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Food allergy | Adverse effect or risk | Documented risk | Soybeans are a major food allergen. Preparation or compound: Soy protein in soybean tempeh |
19 22 |
| Blood sugar balance | Preliminary | Small drops in fasting glucose for fermented soy foods as a group; animal and lab data for tempeh. Preparation or compound: Fermented soy |
9 1 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Fasting blood glucose | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 9 |
| Total cholesterol | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 9 |
| Ferritin and haemoglobin (iron status) | Biological association | Very low certainty | Measured in trials: mixed. A lab change is not the same as a health benefit. | 16 |
| Acyl-ghrelin (hunger hormone) | Biological association | Very low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 12 |
| Urinary daidzein, genistein and equol | Biological association | Low certainty | Measured in trials: raised. A lab change is not the same as a health benefit. | 6 |
| Fraction of calcium absorbed | Biological association | Low certainty | Measured in trials: no significant change. A lab change is not the same as a health benefit. | 5 |
K. Biological pathways
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Protein | Preliminary mechanism | Human | Tempeh is a protein-rich plant food. | 24 |
| Calcium | Preliminary mechanism | Human | Calcium from a tempeh meal was absorbed about as well as from milk in one small study. | 5 |
| Soy isoflavones | Preliminary mechanism | Human | Absorbed from tempeh; effect on health not shown here. | 6 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Protein | Biological association | Human | Also the source of the soy allergen. Preparation or compound: Cake of soybeans |
24 23 |
| Copper and manganese | Biological association | Human | Nutrients the body needs; no trial of tempeh for these was read. Preparation or compound: Cake of soybeans |
24 |
| Calcium and iron | Biological association | Human | Calcium from a tempeh meal was absorbed about as well as from milk in one small study. Preparation or compound: Cake of soybeans |
24 23 5 |
| Soy isoflavones (daidzein, genistein) and their forms | Biological association | Human | Absorbed after eating tempeh (urinary levels higher than after milk). A scoping review says fermentation raises isoflavone aglycones. Preparation or compound: Cake of soybeans |
6 18 |
| Short peptides and GABA | Biological association | Lab | Peptides with antioxidant and ACE-inhibitor activity and raised GABA and amino acids are described in the lab; no human effect shown. Preparation or compound: Fermented soybeans |
18 |
| Biogenic amines (histamine, tyramine) | Biological association | Human | Can raise blood pressure or cause headache in sensitive people or people on MAOIs. Preparation or compound: Fermented soybeans |
11 13 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 26, 2026).
The evidence
The research centre for Tempeh. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We started from our existing tempeh summary, re-checked nutrition against saved USDA FoodData Central data, read the health agency pages (NCCIH, FDA) and re-read PubMed abstracts for trials and reviews. Only abstracts were read for studies. Items we could not verify are flagged in the research gaps.
Study library: every study we checked 24
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Ayustaningwarno 2026 A Critical Review of Antidiabetic Properties of Tempeh From Various Substrates. J Food Sci · PMID 41906408 · DOI |
Narrative review animal and cell |
In vitro and in vivo (animal) studies of tempeh | Tempeh from soybeans and other substrates Tempeh |
Soybean tempeh consistently lowered blood glucose in diabetic animal models and increased liver glycogen storage. Tempeh from other beans and grains also lowered glucose in animals. The authors call tempeh a promising dietary intervention; the review covers laboratory and animal studies only. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Glucose and related markers in cells and diabetic animals Limitations: Laboratory and animal studies only; no human trial is reviewed in the abstract, so no benefit in people is shown. Funding and conflicts: Listed institutional support (Universitas Diponegoro); no industry funding is stated in the abstract. Read: abstract |
| Buckle 1990 Inhibition of bongkrek acid and toxoflavin production in tempe bongkrek containing Pseudomonas cocovenenans. J Appl Bacteriol · PMID 2391293 · DOI |
Laboratory analysis n/a |
Lab-made tempe bongkrek (coconut) and coconut culture medium | Tempe bongkrek: partially defatted coconut fermented with Rhizopus oligosporus, contaminated with Pseudomonas cocovenenans Coconut tempeh-type product (not soybean) |
Adding 2% salt reduced but did not stop bongkrek acid formation. Salt together with acidifying to pH 4.5 with acetic acid stopped toxin formation by three strains. This is about coconut-based tempe bongkrek, not soybean tempeh. Not applicable (Not applicable) Methods, limits and fundingOutcomes: Bongkrek acid and toxoflavin production Limitations: A 1990 lab study of coconut tempe bongkrek. Funding and conflicts: Listed as non-US government research support. Read: abstract |
| Gatta 2023 Interference or Noninterference Between Soy and Levothyroxine: That Is the Question. A Narrative Review of Literature. Endocr Pract · PMID 37633413 · DOI |
Narrative review n/a |
Case reports, case series and studies up to November 2022 | Soy products and levothyroxine Soy products |
Few data, mainly case reports, suggest soy may interfere with levothyroxine tablets. The only prospective randomised crossover study found no difference. The authors think any effect has little clinical impact. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Levothyroxine absorption Limitations: Mostly case reports; tempeh is not named in the abstract. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Gillman 2018 A reassessment of the safety profile of monoamine oxidase inhibitors: elucidating tired old tyramine myths. J Neural Transm · PMID 30255284 · DOI |
Narrative review n/a |
Review of over 150 recent papers on tyramine in foods | Foods and MAOIs Foods |
Modern foods contain much less tyramine than in the past, and few foods now have problematically high levels. The author says the risk has been overstated, but that people differ and doctors' judgement and some care are still needed. Tempeh is not named in the abstract. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Tyramine in modern foods and blood pressure responses with MAOIs Limitations: A narrative review by a single author; the abstract does not name tempeh. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Haron 2010 Absorption of calcium from milk and tempeh consumed by postmenopausal Malay women using the dual stable isotope technique. Int J Food Sci Nutr · PMID 19995131 · DOI |
Randomized crossover trial |
20 20 postmenopausal Malay women |
Tempeh (a traditional fermented soy product), 206 g, versus milk (114 g), each with 130 mg calcium Tempeh meal As given in the trial (206 g tempeh); trial detail, not advice Two study phases one month apart · vs Milk |
Calcium absorption from tempeh did not differ significantly from milk. The authors say that because tempeh has less calcium per serving, four servings would be needed to get the same absorbed calcium as a 4-ounce glass of milk. Absorption 36.9 +/- 10.6% (tempeh) versus 34.3 +/- 8.6% (milk); not significantly different (Not given in the abstract) Methods, limits and fundingOutcomes: Calcium absorption measured with stable calcium isotopes in 24-hour urine Limitations: Very small study in postmenopausal Malay women only. The abstract does not name the funder. The tempeh used had about 130 mg calcium in 206 g, which is lower than the USDA figure for raw tempeh, so products differ. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Haron 2011 Apparent bioavailability of isoflavones in urinary excretions of postmenopausal Malay women consuming tempeh compared with milk. Int J Food Sci Nutr · PMID 21574819 · DOI |
Clinical trial |
Postmenopausal Malay women (the same calcium absorption study); 240 g tempeh versus milk | Tempeh, 240 g, versus milk Tempeh 240 g tempeh (trial detail, not advice) Urine collected after the meal · vs Milk |
Urinary daidzein, genistein and equol were significantly higher after tempeh than after milk. Almost all women excreted equol, but only one could be classed as an equol producer. Daidzein 47.06 vs 3.51 umol/h; genistein 33.27 vs 2.79 umol/h; equol 24.35 vs 0 umol/h (P < 0.05) (Not given in the abstract) Methods, limits and fundingOutcomes: Urinary daidzein, genistein and equol Limitations: Milk has almost no isoflavones, so this shows tempeh supplies isoflavones that are absorbed. It is a marker, not a health outcome. Small study. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Li 2026 Soy Foods Consumption and Multiple Health Outcomes: An Umbrella Review of Meta-Analyses. Mol Nutr Food Res · PMID 41327897 · DOI |
Umbrella review |
23 meta-analyses of observational research (39 outcomes) and one meta-analysis of randomised trials (4 outcomes) | Soy foods of all kinds, including fermented soy products Soy foods · vs Lower soy intake |
The authors conclude soy foods are more beneficial than harmful, especially for cancer and heart and metabolic diseases. They add that the benefits of fermented soy products were inconclusive and that some studies indicated possible adverse effects. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Many health outcomes Limitations: An umbrella review of mostly observational meta-analyses. Tempeh is not named in the abstract. Funding and conflicts: Listed as non-US government research support (a Chinese national public health project); specific conflicts are not given in the abstract. Read: abstract |
| Mah 2019 Bacterial Production and Control of Biogenic Amines in Asian Fermented Soybean Foods. Foods · PMID 30823593 · DOI |
Narrative review n/a |
Review of biogenic amines in Asian fermented soybean foods | Fermented soybean foods Fermented soybean foods |
The amounts of biogenic amines in most products have been reported to be within safe levels, but certain products contain vasoactive amines greater than toxic levels. No law regulates them in these foods anywhere. Tempeh is not named in the abstract. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Biogenic amines in fermented soybean foods Limitations: Tempeh is not named in the abstract, so tempeh-specific levels are not known from it. Funding and conflicts: Listed support from the National Research Foundation of Korea. Read: abstract |
| Maleki Sedgi 2025 Effect of fermented soybean on metabolic outcomes, anthropometric indices, and body composition: a systematic review and meta-analysis of clinical trials. Food Funct · PMID 39763426 · DOI |
Systematic review meta analysis |
15 randomised trials of fermented soy products (searched to March 2024) | Fermented soy products of various kinds (the abstract does not say which) Fermented soy foods Not given in the abstract Not given in the abstract · vs Controls |
Fermented soy gave small beneficial changes in BMI, waist circumference, visceral fat, fasting glucose and total cholesterol compared with controls. Other markers did not change significantly. BMI -0.14 kg/m2; waist -1.50 cm; visceral fat -692.17 mm2; fasting glucose -6.39 mg/dL; total cholesterol -5.0 mg/dL (weighted mean differences) (BMI -0.28 to -0.01; waist -2.94 to -0.07; visceral fat -1011.58 to -372.77; glucose -10.38 to -2.40; total cholesterol -6.60 to -3.39) Methods, limits and fundingOutcomes: BMI, waist circumference, visceral fat, fasting glucose, total cholesterol and other markers Limitations: Fermented soy of mixed kinds, not tempeh alone. Several results sit close to no effect. The abstract does not report how certain the evidence is. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Marco 2021 The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. Nat Rev Gastroenterol Hepatol · PMID 33398112 · DOI |
Consensus statement n/a |
Expert panel convened September 2019 | Fermented foods in general Fermented foods |
The panel defines fermented foods as foods made through desired microbial growth and enzymatic conversions of food components, and says fermented foods are different from probiotics. Not applicable (Not applicable) Methods, limits and fundingOutcomes: Definition, safety, risks and benefits of fermented foods Limitations: A general statement on fermented foods, not specific to tempeh. Funding and conflicts: Listed as non-US government research support; the panel was convened by ISAPP. Read: abstract |
| Montanari 2026 Occurrence and control of biogenic amines in plant-based fermented foods. Crit Rev Food Sci Nutr · PMID 42568231 · DOI |
Narrative review n/a |
Review of plant-based fermented foods including soy products such as soy sauce, miso and tempeh | Plant-based fermented foods Soy-based fermented foods including tempeh |
Amine levels are highly variable and depend on raw materials, ingredients and processing. They occasionally reach potentially harmful concentrations, particularly for histamine. The review covers tempeh among soy products. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Biogenic amines in plant-based fermented foods Limitations: The abstract gives no tempeh-specific numbers. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Noer 2021 Fermented soybean enhances post-meal response in appetite-regulating hormones among Indonesian girls with obesity. Obes Res Clin Pract · PMID 34147377 · DOI |
Randomized crossover trial |
13 13 females aged 18 to 20 with BMI 25 to 30 |
Breakfast containing tempeh (fermented soybean) versus an isocaloric breakfast with non-fermented soybean Tempeh One breakfast of 307 kcal (trial detail, not advice) Single meal, measured for 120 minutes · vs Non-fermented soybean breakfast |
Acyl-ghrelin fell 35% at 30 minutes after the tempeh meal and stayed below baseline to 120 minutes; there was no change after the non-fermented soybean meal. Insulin response was 30% greater and arginine 24% greater at 120 minutes. Reported appetite did not differ between the meals. Acyl-ghrelin -35% at 30 min (P < 0.05); insulin +30% and arginine +24% versus non-fermented at 120 min (P < 0.05) (Not given in the abstract) Methods, limits and fundingOutcomes: Plasma acyl-ghrelin, insulin, arginine and a hunger scale Limitations: Very small single-meal study. Hormone changes are not weight or health outcomes, and people did not report feeling less hungry. Funding and conflicts: Listed as non-US government research support; the funder is not named in the abstract. Read: abstract |
| Saha Turna 2024 A review of biogenic amines in fermented foods: Occurrence and health effects. Heliyon · PMID 38304783 · DOI |
Narrative review n/a |
Review of biogenic amines in fermented foods | Fermented foods in general Fermented foods |
Several fermented foods can contain histamine, tyramine or phenylethylamine at levels above documented toxic doses. Exposure is linked to migraines, raised blood pressure and fast heart rate. Toxicity can occur at levels a hundred times lower than suggested toxic doses, depending on a person's sensitivity, alcohol and certain medicines. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Histamine, tyramine and other amines and health effects Limitations: A general review; tempeh is not named in the abstract. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Shulman 1999 Refining the MAOI diet: tyramine content of pizzas and soy products. J Clin Psychiatry · PMID 10192596 |
Laboratory analysis n/a |
Pizzas, soy sauces and other soybean products tested in the lab | Soy products including tofu (tempeh is not named in the abstract) Soy products |
Soy products varied widely, with clinically significant tyramine in tofu stored for a week and high tyramine in one soy sauce. The authors advised avoiding all soybean products, especially soy sauce and tofu, on an MAOI. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Tyramine content (6 mg or less was considered safe by the authors) Limitations: A 1999 lab analysis, not a trial and not a report of harm. It does not name tempeh. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Wicaksono 2024 Traditionally produced tempeh harbors more diverse bacteria with more putative health-promoting properties than industrially produced tempeh. Food Res Int · PMID 39614549 · DOI |
Laboratory analysis lab |
Traditionally and industrially produced tempeh (microbiome sequencing) | Tempeh Fermented soybean cake · vs Industrial versus traditional tempeh |
Industrial tempeh had less diverse bacteria than traditional tempeh, with fewer lactobacilli and enterobacteria. Bacteria found carry genes for making vitamins B1, B7, B12 and K and short-chain fatty acids. The authors say industrial production ensures biosafety at scale but may in the long term affect gut health. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Bacterial community and gene content Limitations: Gene analysis in the lab; having the genes does not show the amounts in the food or any effect in people. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Wijaya-Erhardt 2011 Fermented soyabean and vitamin C-rich fruit: a possibility to circumvent the further decrease of iron status among iron-deficient pregnant women in Indonesia. Public Health Nutr · PMID 21729487 · DOI |
Randomized trial |
252 252 pregnant women (12 to 20 weeks of pregnancy) in 39 Indonesian villages |
Supplementary food of tempeh and vitamin C-rich fruit, with a little meat; weekly: 600 g tempeh, 30 g meat, 350 g guava, 300 g papaya, 100 g orange Tempeh plus fruit and meat Food given 6 days a week at home (trial detail, not advice) From 12-20 weeks to 32-36 weeks of pregnancy · vs Control group without supplementary food |
Iron status fell in both groups and the average changes were similar. In women who were iron-deficient at the start, the food group had smaller falls in haemoglobin, ferritin and body iron, with results on the edge of significance. The authors say the food might have positive effects on iron deficiency. Smaller falls in iron-deficient women: haemoglobin 1.02 g/l (P = 0.058), ferritin 1.42 ug/l (P = 0.046), body iron 2.57 mg/kg (P = 0.073) (Haemoglobin 0.98 to 1.07; ferritin 1.16 to 1.75; body iron 1.71 to 3.43) Methods, limits and fundingOutcomes: Haemoglobin, ferritin, transferrin receptor, body iron Limitations: Tempeh was given together with meat and fruit, so the effect of tempeh alone cannot be told. Groups were assigned by village. The overall result was no difference; the benefit is a subgroup finding. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Yang 2026 Bongkrekic Acid Poisoning Associated with Burkholderia gladioli: A Systematic Review. Foodborne Pathog Dis · PMID 41668477 · DOI |
Systematic review human and lab |
91 studies of bongkrekic acid poisoning | Traditional fermented foods such as tempe bongkrek, rice noodles and corn products Foods contaminated with Burkholderia gladioli |
Bongkrekic acid poisoning is rare but highly lethal. Outbreaks are linked mainly to traditional fermented foods such as tempe bongkrek, rice noodles and corn products, with case fatality rates of 30% to 100%. The toxin is heat stable. Case fatality 30% to 100% (Not applicable) Methods, limits and fundingOutcomes: Outbreaks, toxicity, detection and prevention Limitations: The abstract does not name soybean tempeh; tempe bongkrek is the coconut-based product. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Yarlina 2026 Unraveling Tempeh through omics: a scoping review of fermentation pathways and functional health benefits. NPJ Sci Food · PMID 41760689 · DOI |
Scoping review lab |
36 articles on tempeh microbes and metabolites (2000 to August 2025) | Tempeh Fermented soybean cake |
Rhizopus and lactic acid bacteria drive the fermentation. Tempeh has short peptides with antioxidant and ACE-inhibitor activity in the lab, and raised levels of amino acids, GABA and isoflavone aglycones. The authors say targeted human studies are needed. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Microbes, enzymes, peptides and metabolites in tempeh Limitations: Laboratory description of what is in tempeh, not health results in people. Funding and conflicts: Listed institutional support (Universitas Padjadjaran). Read: abstract |
| s-fda-allergens US FDA: Food Allergies · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-gbif-glycine-max GBIF Backbone: Glycine max (L.) Merr. (usageKey 5359660) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-gbif-rhizopus GBIF Backbone: Rhizopus oligosporus Saito (usageKey 3386534) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-nccih-soy NCCIH (US National Institutes of Health): Soy: Usefulness and Safety · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-usda-fdc-172467 USDA FoodData Central: Tempeh, cooked (SR Legacy, FDC 172467) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-usda-fdc-174272 USDA FoodData Central: Tempeh (SR Legacy, FDC 174272) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text |
What we do not know yet
- No trial of tempeh on its own was found for blood sugar, cholesterol, weight or gut health; the pooled results are for fermented soy foods in general.
- The blood sugar findings are from animals and the lab.
- Tempeh-specific histamine and tyramine amounts were not read.
- Heavy metals, mould toxins, safe cooking, shelf life, children, gout, kidney advice and cross-reaction with other legume allergies were not researched.
- History, how tempeh is made and tempeh from other beans or grains were not researched.
- A review of tempeh isoflavones and menopausal brain function appeared in searches but its abstract was not read.
How new research is added
New studies are found by a saved PubMed search and placed in a review queue before the page changes.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Metabolic 2
Fasting blood glucose
Lowered in trials
The sugar level in the blood after not eating overnight.
Low certaintyResults and what it means
Why it was measured
It is a standard marker of blood sugar control.
Statistical vs. clinical meaning
A small average fall for fermented soy foods as a group; tempeh alone was not separated out.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 9 | -6.39 mg/dL (95% CI -10.38 to -2.40) with fermented soy versus controls | Adults in 15 randomised trials | Fermented soy products of various kinds |
Total cholesterol
Lowered in trials
All the cholesterol carried in the blood.
Low certaintyResults and what it means
Why it was measured
It is a usual marker in diet trials for heart risk.
Statistical vs. clinical meaning
A small average change; not specific to tempeh.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 9 | -5.0 mg/dL (95% CI -6.60 to -3.39) with fermented soy versus controls | Adults in 15 randomised trials | Fermented soy products of various kinds |
Other 4
Ferritin and haemoglobin (iron status)
Mixed results in trials
Ferritin is the body's iron store marker; haemoglobin carries oxygen in the blood.
Very low certaintyResults and what it means
Why it was measured
To see whether iron status held up during pregnancy.
Statistical vs. clinical meaning
Borderline subgroup result, with tempeh not tested alone.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 16 | Overall similar changes in both groups; in iron-deficient women smaller falls in ferritin (P = 0.046) and haemoglobin (P = 0.058) | 252 pregnant women, Indonesia | Package of tempeh, fruit and a little meat |
Acyl-ghrelin (hunger hormone)
Lowered in trials
A hormone from the stomach that rises before meals and is linked to hunger.
Very low certaintyResults and what it means
Why it was measured
To see how a meal changes appetite-related hormones.
Statistical vs. clinical meaning
A short-term hormone change that was not matched by any change in reported appetite.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | -35% at 30 minutes after tempeh, below baseline until 120 minutes (P < 0.05); no change after non-fermented soybean | 13 young women with BMI 25 to 30 | Tempeh breakfast of 307 kcal versus non-fermented soybean breakfast |
Urinary daidzein, genistein and equol
Raised in trials
Soy isoflavones and one gut-made product, measured in urine.
Low certaintyResults and what it means
Why it was measured
To check that isoflavones from the food are absorbed.
Statistical vs. clinical meaning
Shows exposure only, not a health effect.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 6 | Daidzein 47.06 vs 3.51 umol/h; genistein 33.27 vs 2.79; equol 24.35 vs 0 (tempeh versus milk, P < 0.05) | Postmenopausal Malay women | 240 g tempeh versus milk |
Fraction of calcium absorbed
No significant change in trials
How much of the calcium eaten crosses into the body, measured with isotopes.
Low certaintyResults and what it means
Why it was measured
A food can contain calcium the body does not take up.
Statistical vs. clinical meaning
Absorption from tempeh was similar to milk in this small study.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 5 | 36.9 +/- 10.6% from tempeh versus 34.3 +/- 8.6% from milk, not significant | 20 postmenopausal Malay women | Tempeh meal of 206 g versus 114 g milk, each 130 mg calcium |
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 5
- Soy allergy. Tempeh is traditionally made from soybeans. The US FDA lists soybeans among the major food allergens, and NCCIH says some people are allergic to soy. If you have a soy allergy, soybean tempeh is not safe for you. Tempeh made from other beans or grains was not reviewed here, and cross-contact was not researched. Authoritative guidance 19 22
- MAOI antidepressants, tyramine and histamine. NCCIH reports that soy products high in tyramine, such as tofu and soy sauce, have been linked with dangerously high blood pressure in people taking MAOIs. It does not name tempeh. Reviews say some fermented foods can contain histamine, tyramine and other amines at levels above documented toxic doses, that levels vary a lot with raw materials and processing, and that sensitivity differs between people. A review of plant-based fermented foods covers tempeh and says histamine can occasionally reach potentially harmful concentrations. No tempeh-specific amount was read. If you take an MAOI, or get headaches or flushing after fermented foods, ask your prescriber or pharmacist about tempeh. Authoritative guidance and reviews 22 13 11 8 4
- Coconut tempeh (tempe bongkrek) is a different, dangerous product. Bongkrekic acid poisoning is rare but highly lethal, with case fatality of 30% to 100% in a 2026 systematic review. Outbreaks were linked mainly to traditional fermented foods such as tempe bongkrek (a coconut-based tempeh-type food), rice noodles and corn products, contaminated with the bacterium Burkholderia gladioli. The toxin is heat stable. The abstracts do not name ordinary soybean tempeh as a source. Systematic review and lab 17 2
- Pregnancy and breastfeeding. NCCIH says soy in amounts greater than those commonly found in foods may be unsafe in pregnancy, and that little is known about such larger amounts while breastfeeding. It does not say that ordinary soy food is unsafe. Ask your midwife, doctor or dietitian about your own diet. Authoritative guidance 22
- Thyroid medicine (levothyroxine) and soy. A 2023 review found mainly case reports suggesting soy products may interfere with levothyroxine tablets, and one randomised crossover study with no difference. The authors think any effect has little clinical impact. Tempeh is not named in the abstract. Do not change a thyroid medicine on your own; ask your prescriber. Case reports and review 3
Side effects 3
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Allergic reactions to soy, from mild itching and hives to anaphylaxis Statements are for soy in general, not tempeh specifically. | No frequency read for tempeh. | can be severe (anaphylaxis) Not described in the sources read. | Authoritative guidance 19 22 |
| Bloating, constipation, diarrhea and nausea NCCIH's list is for soy products and supplements in general. | No frequency given. | mild Not described. | Authoritative guidance 22 |
| Headache, raised blood pressure or fast heart rate in people sensitive to biogenic amines (histamine, tyramine) Reviews are about fermented foods in general; amines in tempeh vary with how it is made and stored. | No frequency read. | varies Not described. | Review 13 11 |
Liver
No liver injury from eating tempeh was found in the sources read. A liver-safety source (such as LiverTox) was not searched for tempeh. Bongkrekic acid poisoning from contaminated coconut tempeh-type food, described above, does damage the liver and other organs. 17
How often. No frequency was found for tempeh.
Monitoring. No agency monitoring advice was found.
This is a safety connection. It is not evidence that Tempeh supports liver health.
Medicines and supplements 3
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| MAOI antidepressants (monoamine oxidase inhibitors) prescription | Tyramine from some fermented or stored foods can raise blood pressure when an MAOI blocks its breakdown. | NCCIH names tofu and soy sauce, not tempeh. A 1999 lab analysis found tyramine in stored tofu; a 2018 review says modern foods have much less tyramine and the risk has been overstated, though people differ. Neither abstract names tempeh, and no tempeh-specific tyramine amount was read. | Authoritative guidance and lab analysis Not enough evidence 22 14 4 11 | Ask your prescriber or pharmacist before eating tempeh on an MAOI. |
| Levothyroxine (thyroid hormone tablets) prescription | Soy products may reduce absorption of levothyroxine tablets; this is based mainly on case reports. | One randomised crossover study found no difference, and the authors judge any effect to have little clinical impact. Tempeh was not specifically studied. | Case reports Very low certainty 3 | Do not change your medicine yourself. Ask your prescriber whether timing matters for you. |
| Medicines for diabetes, blood pressure or cholesterol prescription | Fermented soy has been studied for small changes in glucose and cholesterol; a large change in diet could in theory add to a medicine's effect. | No source read tied tempeh to a specific interaction with these medicines. This is a general caution, not a documented interaction. | Theoretical Not enough evidence 9 | Tell your clinician or pharmacist if you make a big change to what you eat. |
Who should check first 5
| Situation | Advice | Evidence |
|---|---|---|
| Known or suspected soy allergy | Avoid soybean tempeh and other soy foods, and read labels. Ask an allergist about your own case. For trouble breathing or swelling of the face, lips or throat, call 911 or your local emergency number. | Authoritative guidance 19 22 |
| Taking an MAOI antidepressant | Ask your prescriber or pharmacist about tempeh before eating it. | Authoritative guidance 22 |
| Histamine sensitivity or migraines triggered by fermented foods | Reviews say sensitivity to biogenic amines differs between people. Ask your clinician or dietitian whether fermented foods suit you. | Review 13 |
| Pregnancy or breastfeeding | Ordinary soy food is not singled out as unsafe by the source read. NCCIH says soy in amounts greater than those found in foods may be unsafe in pregnancy. Ask your midwife, doctor or dietitian. | Authoritative guidance 22 |
| Kidney disease | Raw tempeh has 412 mg of potassium and 266 mg of phosphorus per 100 g by USDA data. No tempeh-specific kidney advice was read; ask your kidney team or dietitian how it fits your limits. | Reference data 24 |
Overdose, product quality and regulators
Summary. No toxicity from soybean tempeh as ordinary food was found in the sources read. The safety points are allergy, amines and the separate danger of contaminated coconut tempeh-type food.
Animal. Not reviewed.
High dose or long term signals. NCCIH says soy in pregnancy may be unsafe in amounts above those in foods. The 2026 umbrella review said some studies of fermented soy products indicated possible adverse effects, without naming them in the abstract.
Overdose response. Not found.
Genotoxicity. Not researched.
Tempeh is made by growing a mould (Rhizopus) on cooked soybeans, with other bacteria present. Food safety depends on the product and its handling; only a few points were read.
Bongkrekic acid in coconut tempeh-type food. Bongkrekic acid poisoning is linked to tempe bongkrek (coconut), not reported in the abstracts for soybean tempeh. In a 1990 lab study, 2% salt plus acidifying to pH 4.5 stopped toxin formation in lab-made tempe bongkrek. 17 2
Biogenic amines. Amine levels in fermented soy foods are very variable; reviews say most products are within safe levels, but some contain vasoactive amines above toxic levels, and histamine can occasionally reach potentially harmful concentrations in plant-based fermented foods. 8 11
Microbes in traditional and industrial tempeh. A sequencing study found industrial tempeh had a less diverse bacterial community than traditional tempeh, with fewer lactobacilli and enterobacteria. The authors say industrial production ensures biosafety at scale. This is a lab description, not a report of harm. 15
| Body | Action | Date |
|---|---|---|
| US FDA (United States) | Food Allergies: soybeans are one of the major food allergens; soy must be named on packaged food labels. source | 2026-03-11 |
| NCCIH (US National Institutes of Health) (United States) | Soy: Usefulness and Safety. Some people are allergic; high-tyramine soy products such as tofu and soy sauce and MAOIs have been reported to cause dangerously high blood pressure; soy above food amounts may be unsafe in pregnancy; little is known about larger amounts while breastfeeding. source | 2025-04 |
When to get medical help
- Trouble breathing, wheezing, swelling of the lips, face, tongue or throat, widespread hives, repeated vomiting, dizziness or collapse after eating tempeh or another soy food (possible anaphylaxis): use epinephrine if prescribed, then call 911 or your local emergency number
- Severe headache, pounding heart or signs of dangerously high blood pressure after eating tempeh while taking an MAOI: seek urgent medical help
- Vomiting, severe weakness or confusion after eating homemade or village-made coconut tempeh-type food (tempe bongkrek): seek urgent medical help and say what was eaten
Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
What is tempeh?
Tempeh is a firm cake of cooked soybeans bound together by a mould, from Indonesia. The fermentation is driven by Rhizopus mould and lactic acid bacteria. It is eaten as a plant protein food.
How much protein does tempeh have?
Is tempeh a good source of calcium?
Does tempeh help iron levels in pregnancy?
A trial of 252 pregnant women found no overall difference in iron status from a package of tempeh, fruit and a little meat. Falls in iron markers were smaller in iron-deficient women, but the results were borderline and tempeh was not tested alone.
Does tempeh lower blood sugar or cholesterol?
Does tempeh help with diabetes?
No human trial of tempeh for diabetes was read. A 2026 review found soybean tempeh lowered blood glucose in diabetic animals and in lab tests, which does not show benefit in people.
Is tempeh a probiotic food?
Who should avoid tempeh because of soy allergy?
Can I eat tempeh if I take an MAOI antidepressant?
Can tempeh cause headaches or flushing?
What is tempe bongkrek and is it the same as tempeh?
Is tempeh safe in pregnancy?
NCCIH says soy in amounts greater than those commonly found in foods may be unsafe in pregnancy, and that little is known about larger amounts while breastfeeding. It does not single out ordinary soy food. Ask your midwife or doctor.
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Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against the sources listed.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-26
- Last substantive update
- 2026-10-26
- How we research
- We started from our existing tempeh summary, re-checked nutrition against saved USDA FoodData Central data, read the health agency pages (NCCIH, FDA) and re-read PubMed abstracts for trials and reviews. Only abstracts were read for studies. Items we could not verify are flagged in the research gaps.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown. Funding is stated where an abstract gives it; most abstracts do not.
Sources 24
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Ayustaningwarno F, Jusman TNG, Afifah DN. A Critical Review of Antidiabetic Properties of Tempeh From Various Substrates.. J Food Sci. 2026. PMID 41906408. DOI 10.1111/1750-3841.71014. (abstract)
- Buckle KA, Kartadarma EK. Inhibition of bongkrek acid and toxoflavin production in tempe bongkrek containing Pseudomonas cocovenenans.. J Appl Bacteriol. 1990. PMID 2391293. DOI 10.1111/j.1365-2672.1990.tb05222.x. (abstract)
- Gatta E, Maltese V, Cavadini M, et al.. Interference or Noninterference Between Soy and Levothyroxine: That Is the Question. A Narrative Review of Literature.. Endocr Pract. 2023. PMID 37633413. DOI 10.1016/j.eprac.2023.08.009. (abstract)
- Gillman PK. A reassessment of the safety profile of monoamine oxidase inhibitors: elucidating tired old tyramine myths.. J Neural Transm. 2018. PMID 30255284. DOI 10.1007/s00702-018-1932-y. (abstract)
- Haron H, Shahar S, O'Brien KO. Absorption of calcium from milk and tempeh consumed by postmenopausal Malay women using the dual stable isotope technique.. Int J Food Sci Nutr. 2010. PMID 19995131. DOI 10.3109/09637480903348080. (abstract)
- Haron H, Ismail A, Shahar S. Apparent bioavailability of isoflavones in urinary excretions of postmenopausal Malay women consuming tempeh compared with milk.. Int J Food Sci Nutr. 2011. PMID 21574819. DOI 10.3109/09637486.2011.570742. (abstract)
- Li W, Wei X, Zhang J, et al.. Soy Foods Consumption and Multiple Health Outcomes: An Umbrella Review of Meta-Analyses.. Mol Nutr Food Res. 2026. PMID 41327897. DOI 10.1002/mnfr.70255. (abstract)
- Mah JH, Park YK, Jin YH, et al.. Bacterial Production and Control of Biogenic Amines in Asian Fermented Soybean Foods.. Foods. 2019. PMID 30823593. DOI 10.3390/foods8020085. (abstract)
- Maleki Sedgi F, Mozaffari N, Pashaei MR, et al.. Effect of fermented soybean on metabolic outcomes, anthropometric indices, and body composition: a systematic review and meta-analysis of clinical trials.. Food Funct. 2025. PMID 39763426. DOI 10.1039/d4fo02668c. (abstract)
- Marco ML, Sanders ME, Gaenzle M, et al.. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods.. Nat Rev Gastroenterol Hepatol. 2021. PMID 33398112. DOI 10.1038/s41575-020-00390-5. (abstract)
- Montanari C, Comas-Basté O, Barbieri F. Occurrence and control of biogenic amines in plant-based fermented foods.. Crit Rev Food Sci Nutr. 2026. PMID 42568231. DOI 10.1080/10408398.2026.2714471. (abstract)
- Noer ER, Dewi L, Kuo CH. Fermented soybean enhances post-meal response in appetite-regulating hormones among Indonesian girls with obesity.. Obes Res Clin Pract. 2021. PMID 34147377. DOI 10.1016/j.orcp.2021.06.005. (abstract)
- Saha Turna N, Chung R, McIntyre L. A review of biogenic amines in fermented foods: Occurrence and health effects.. Heliyon. 2024. PMID 38304783. DOI 10.1016/j.heliyon.2024.e24501. (abstract)
- Shulman KI, Walker SE. Refining the MAOI diet: tyramine content of pizzas and soy products.. J Clin Psychiatry. 1999. PMID 10192596. (abstract)
- Wicaksono WA, Akinyemi OE, Wassermann B. Traditionally produced tempeh harbors more diverse bacteria with more putative health-promoting properties than industrially produced tempeh.. Food Res Int. 2024. PMID 39614549. DOI 10.1016/j.foodres.2024.115030. (abstract)
- Wijaya-Erhardt M, Muslimatun S, Erhardt JG. Fermented soyabean and vitamin C-rich fruit: a possibility to circumvent the further decrease of iron status among iron-deficient pregnant women in Indonesia.. Public Health Nutr. 2011. PMID 21729487. DOI 10.1017/S1368980011000954. (abstract)
- Yang H, Zhao L, Duan M. Bongkrekic Acid Poisoning Associated with Burkholderia gladioli: A Systematic Review.. Foodborne Pathog Dis. 2026. PMID 41668477. DOI 10.1177/15353141251413448. (abstract)
- Yarlina VP, Tandra JL, Indiarto R. Unraveling Tempeh through omics: a scoping review of fermentation pathways and functional health benefits.. NPJ Sci Food. 2026. PMID 41760689. DOI 10.1038/s41538-026-00754-2. (abstract)
- . US FDA: Food Allergies. . . (full-text)
- . GBIF Backbone: Glycine max (L.) Merr. (usageKey 5359660). . . (full-text)
- . GBIF Backbone: Rhizopus oligosporus Saito (usageKey 3386534). . . (full-text)
- . NCCIH (US National Institutes of Health): Soy: Usefulness and Safety. . . (full-text)
- . USDA FoodData Central: Tempeh, cooked (SR Legacy, FDC 172467). . . (full-text)
- . USDA FoodData Central: Tempeh (SR Legacy, FDC 174272). . . (full-text)
