Mushrooms · Medicinal and culinary mushroom
Tremella
Tremella fuciformis · also called Snow fungus, snow mushroom, silver ear, white jelly mushroom (names used in the papers cited)
Tremella, or snow fungus, is a soft, jelly-like mushroom eaten in Asian soups and desserts and used in skin-care products. Human research is thin: one small memory trial, one small prediabetes trial and a gel skin test. Most of the rest is lab work. The most important caution is food safety: tremella that has been soaked or kept too long can grow bacteria that make a deadly toxin with no antidote.
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 Tremella
Tremella (snow fungus) is a jelly-like mushroom eaten across Asia and used in skin care. Human research is small: one 8-week memory trial, one 12-week prediabetes trial and a short hand-gel test. Immune, antioxidant and cholesterol claims come from lab and animal work. The main danger found is food spoilage: tremella soaked or kept too long can carry a bacterial toxin that has caused deaths.
What it is
Tremella fuciformis is a jelly fungus in the family Tremellaceae. GBIF lists it as an accepted species. English names include snow fungus, snow mushroom, silver ear and white jelly mushroom. Do not confuse it with Tremella mesenterica, the yellow brain fungus, which is a different species, or with black fungus (wood ear), which is a different type of fungus.
Products include the fresh or dried mushroom, powders, polysaccharide extracts, mycelium products and skin-care ingredients.
Traditional and current uses
Reviews describe tremella as a food and medicinal ingredient in traditional Chinese medicine and in Asian cooking for centuries. Today its water-holding polysaccharides are used in skin-care products, foods and drinks. Traditional use is not proof that it works or is safe.
What the research shows
In an 8-week trial of 75 adults with memory complaints, those taking a tremella supplement did better than placebo on a memory questionnaire and on some memory and thinking tests. Adverse events were similar in all groups. A second trial used a drink mixing fish roe, snow fungus and yeast, so its results cannot be credited to tremella.
In 56 overweight adults with prediabetes, a tremella drink for 12 weeks was followed by HbA1c falling from 6.03% to 5.96% and waist size from 95.2 to 93.46 cm. These are very small changes from one exploratory trial.
A hand gel with tremella extract moistened skin better than placebo for up to 3 hours in 20 people. Most other skin findings, and the immune and antioxidant claims, come from cells and animals. We found no human cholesterol trial.
The mushroom, extracts and skin-care ingredients are different
Results from one product cannot be applied to another. The memory trial used a supplement, the prediabetes trial a beverage, the skin test an alcohol gel, and lab work used purified polysaccharides and a hyaluronic-acid-type molecule. The abstracts do not say whether trial products came from fruiting body or mycelium. One lab study of fungal hyaluronic acid came from authors linked to the company that makes the product.
Legal and regulatory status
We did not read statements about tremella from the US FDA, EFSA, EMA, UK Food Standards Agency, WHO, LiverTox or LactMed, so none is stated here. The only official-style advice we read is from China CDC Weekly reports on bongkrekic acid poisoning. Rules differ by country and change.
At a glance
Traditional uses history, not proof
- Used as a food and medicinal ingredient in traditional Chinese medicine, and popular in Asian herbal medicine and cooking (Wu 2019; Mineroff 2023).
- Described as a traditional edible and medicinal fungus used in Asian countries for centuries (Li 2025).
- Today its polysaccharides are used in foods, drinks and skin-care products (reviews).
Studied for research
- Memory and thinking complaints (one small trial), low
- Anxiety and fatigue (a three-ingredient mixture), very low
- HbA1c and waist size in prediabetes (one small trial), very low
- Skin moisture (a hand gel and cell studies), very low
- Immune and antioxidant effects (lab and animal work), insufficient
- Cholesterol, insufficient (no human trial found)
Main compounds
- Polysaccharides (the main bioactive part, per reviews)
- Fungal-derived hyaluronic acid-type molecule (one company-linked lab study)
Common forms
- Fresh or soaked dried fruiting body (soups, desserts)
- Dried slices or powder
- Hot-water polysaccharide extracts
- Capsules, tablets and drinks
- Mycelium or fermentation products
- Skin-care ingredient
Research links: Memory trial (Ban 2018, abstract) · Prediabetes trial (2024, abstract) · Skin review (Mineroff 2023, abstract) · Bongkrekic acid outbreaks in China 2010-2020 · Fungi sampling in Shanghai (China CDC Weekly) · Forensic review of bongkrekic acid poisoning · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Tremella fuciformis
- Naming authority
- Berk. (GBIF)
- Common names
- Snow fungus (English); Snow mushroom (English (Mineroff 2023)); Silver ear (English (Luan 2026)); White jelly mushroom (English (Lourith 2021)); Yin er (Chinese (summary-only, from an earlier internal summary))
- Family or group
- Tremellaceae (a family of jelly fungi), not a plant
- Classification
- Fungi > Basidiomycota > Tremellomycetes > Tremellales > Tremellaceae > Tremella > Tremella fuciformis
- Native range
- Not checked in the sources read.
- Habitat
- Not checked in the sources read. Wu 2019 and Li 2025 describe it as widely cultivated and used in Asian countries.
- What it looks like
- Fruiting body: Described in the sources as a soft, jelly-like edible mushroom (the names 'white jelly mushroom' and 'silver ear' refer to its look). No detailed description was read.
- Cultivation
- Wu 2019 says it is widely cultivated. Some extracts come from liquid (submerged) fermentation of mycelium; the abstracts read do not describe the processes.
- Harvest and processing
- Sold fresh or dried and soaked before cooking. Soaking time matters for safety (see Safety).
- Look-alikes and adulterants
- Name: Tremella mesenterica (yellow brain fungus); Note: A different species with its own page on this site. One trial of its cultured mycelium tablets did not clear Helicobacter pylori in 52 patients, but that is not evidence about snow fungus.; Name: Black fungus (wood ear, Auricularia); Note: A different, dark jelly-type fungus often stored and prepared the same way; it is the other main food linked to bongkrekic acid poisoning in the reports read.
- Sustainability and conservation
- Not checked.
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| China and Asian cooking | Mineroff and Jagdeo describe snow mushroom as an edible mushroom historically popular in herbal and Asian medicine and cuisine. Wu and colleagues describe it as widely cultivated and used as food and as a medicinal ingredient in traditional Chinese medicine. | p36757441 |
| Modern food and skin care | Li and colleagues call it a traditional edible and medicinal fungus used in Asian countries for centuries; its polysaccharides are now used in foods, drinks and cosmetics. | p41346688 |
Traditional use shows how it was used. It does not show that it works or is safe today.
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 |
|---|---|---|---|---|
| Tremella polysaccharides (TFPs) | polysaccharide | Fruiting body and fermentation products | Reviews call them the main bioactive constituents and list immune, antioxidant, blood-sugar, gut-microbe and skin-related activities, mostly from lab and animal work. 6 14 9 | Laboratory research |
| Fungal-derived hyaluronic acid | polysaccharide | Extract | One company-linked lab study reports a hyaluronic-acid-type molecule extracted from the fungus that is stable in simulated digestion. This chemistry was not independently verified here. 12 | Laboratory research |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Skin cell growth and collagen (AKT signalling) | AKT | In human skin fibroblasts, a commercial extract raised DNA and collagen production and p-AKT staining in the lab. 13 | Laboratory research |
| Hyaluronan receptor CD44 in skin and cartilage cells | CD44 | Fungal-derived hyaluronic acid raised CD44 expression and uptake of the molecule in chondrocytes and keratinocytes in lab models. 12 | Laboratory research |
Absorption, metabolism and elimination
- Absorption
- Only a lab gut-cell barrier model was read; no human data.
- Distribution
- Not found.
- Metabolism
- Not found in people.
- Elimination
- Not found.
- Bioavailability
- Not established.
Isolated compounds versus whole extracts
The memory trial used a supplement and the prediabetes trial used a beverage; the lab work used extracts, purified polysaccharides and an isolated hyaluronic acid. Results from one cannot be applied to another, or to eating the mushroom in soup.
Nutritional composition
Tremella is eaten as food, but no measured vitamin or mineral values were read, so no nutrition claim is made.
1 low certainty3 very low certainty2 not enough evidence
What was looked at
The 6 benefits and uses checked for Tremella, each with how strong the evidence is. Tap one to open it.
- Memory and thinking complaintsLow certainty
- Anxiety, tiredness and quality of life (mixture only)Very low certainty
- Blood sugar markers and waist size in prediabetesVery low certainty
- Skin moisture and skin careVery low certainty
- Immune and antioxidant effects (lab and animal work)Not enough evidence
- Cholesterol and blood sugar (reported in reviews)Not enough evidence
Lab markers tracked in the studies
Subjective memory complaint questionnaire scoreShort-term memory and executive-function testsBrain scan gray matter volume (exploratory)HbA1c (average blood sugar over about 3 months)Waist circumferenceSkin moisture (topical gel)
What is Tremella good for?
The uses people ask about and how strong the human evidence is for each. None is proven. Read this together with the Safety tab.
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.
Memory and thinking complaints
Low certaintyOne 8-week trial in 75 adults with memory complaints found better scores on a memory questionnaire and some thinking tests with a tremella supplement than with placebo. A second trial used a drink that mixed fish roe, snow fungus and yeast, so it cannot be credited to tremella alone. Neither has been repeated.
2 studiesBan 2018 used a tremella supplement; the abstract does not say whethe…
Studies, doses and limits
What the trials found
Ban 2018: 75 adults with subjective cognitive impairment took a tremella supplement (two amounts) or placebo for 8 weeks. The tremella groups scored better on the memory complaint questionnaire and on short-term memory and executive-function tests. Adverse events were similar in all groups. Lin 2023: 64 adults took a fish roe, snow fungus and yeast drink or placebo for 8 weeks and did better on some memory tests, with less anxiety and fatigue.
Results
Ban 2018: greater improvement than placebo on the questionnaire total score and on short-term memory and executive-function tests (the abstract gives no figures).
Why this rating
One small placebo-controlled trial of tremella alone (only 15 on placebo), 8 weeks, with no figures in the abstract and no repeat. The second trial tested a mixture.
Form and dose studied
Ban 2018 used a tremella supplement; the abstract does not say whether it came from fruiting body or mycelium. Lin 2023 used a drink with three ingredients. No amounts are given here.
Who was studied
Adults with subjective memory complaints (not dementia)
Limits
Small, short, one product each; people knew they had memory complaints, so expectation could matter; subjective questionnaire was the main measure. The results do not apply to healthy people, to dementia or to eating tremella as food.
Why researchers looked
Tremella polysaccharides have been reported in lab and animal work to repair memory impairment (Wu 2019 review); that has led to small human trials.
Traditional use
Tremella is an old food and medicine ingredient in China (reviews). Memory is not named as a traditional use in the sources we read.
Proposed mechanism Laboratory research
Reviews list memory-repairing effects among reported activities of the polysaccharides, mostly from cell and animal work. The trial also ran an exploratory brain scan that found group differences in four brain areas, which does not show how it works.
A proposed mechanism does not show that the effect happens in people.
Adverse events were similar to placebo in Ban 2018. Longer-term safety is not known.
Anxiety, tiredness and quality of life (mixture only)
Very low certaintyIn the three-ingredient drink trial (fish roe, snow fungus, yeast), anxiety and fatigue scores fell and quality of life improved after 8 weeks. Because the drink had three ingredients, no part of this can be credited to snow fungus.
1 studiesCombination drink (fish roe, snow fungus, yeast).
Studies, doses and limits
What the trials found
64 adults with cognitive complaints took the formula drink or placebo for 8 weeks. Anxiety and fatigue fell and quality of life improved in the drink group (abstract, no numbers).
Results
Reductions in anxiety and fatigue and better quality of life reported; no figures in the abstract.
Why this rating
One small trial of a mixture; no figures; funded under an industry-university programme.
Form and dose studied
Combination drink (fish roe, snow fungus, yeast).
Who was studied
Adults with subjective cognitive complaints
Limits
Cannot separate the effect of snow fungus from fish roe and yeast.
Why researchers looked
The trial team tested a mixed drink for thinking and mood together.
Traditional use
Not described in the sources we read.
Proposed mechanism Unknown
No mechanism was tested in the trial.
A proposed mechanism does not show that the effect happens in people.
Not described in the abstract.
Blood sugar markers and waist size in prediabetes
Very low certaintyOne 12-week trial in 56 overweight adults with prediabetes found a very small drop in HbA1c and waist size with a tremella drink. The authors call it exploratory. HbA1c fell by about 0.07 percentage points.
3 studiesA once-daily tremella beverage; its make-up is not described in the a…
Studies, doses and limits
What the trials found
56 adults with overweight or obesity and prediabetes took a Tremella fuciformis drink or placebo for 12 weeks. In the tremella group HbA1c went from 6.03% to 5.96% (p = 0.047) and waist from 95.2 cm to 93.46 cm (p = 0.022). No adverse events were reported.
Results
HbA1c 6.03 to 5.96% (p = 0.047, Cohen's d 0.39); waist 95.2 to 93.46 cm (p = 0.022, Cohen's d 0.45)
Effect sizes as reported
Small (Cohen's d about 0.4)
Why this rating
One small exploratory trial; the changes are tiny; the abstract reports within-group changes; not repeated.
Form and dose studied
A once-daily tremella beverage; its make-up is not described in the abstract. No amounts are given here.
Who was studied
Adults with overweight or obesity and prediabetes (Thailand)
Limits
56 people, 12 weeks. A 0.07-point HbA1c change is too small to matter on its own. Not a treatment for prediabetes or diabetes.
Why researchers looked
Reviews list lowering of blood sugar among reported activities of the mushroom's polysaccharides; the trial tested a beta-glucan-containing drink.
Traditional use
Not described in the sources we read.
Proposed mechanism Unknown
Reviews attribute blood-sugar effects to the polysaccharides, but the abstracts do not separate lab, animal and human work. No mechanism was tested in the trial.
A proposed mechanism does not show that the effect happens in people.
No adverse events reported. People who take blood-sugar medicines should ask their doctor or pharmacist before adding any new product.
Skin moisture and skin care
Very low certaintySnow fungus polysaccharide is used in creams because it holds water. In a small test, a hand gel with the extract moistened skin better than a placebo gel for up to 3 hours. Most other skin findings are from cells and animals. Nobody has tested whether eating tremella changes the skin.
4 studiesThe human test was a topical alcohol gel; the lab work used extracts …
Studies, doses and limits
What the trials found
20 volunteers tried an alcohol hand gel with tremella polysaccharide extract and a placebo gel. The tremella gel was not irritating and moistened the skin better than placebo at every time point up to 180 minutes (P < .05). The review by Mineroff and Jagdeo says most skin studies are in cell cultures and animals and that clinical research is needed.
Results
Better skin moisture than placebo gel up to 180 minutes (P < .05); no figures in the abstract.
Why this rating
One small short test of a topical gel in 20 people, plus cell studies. No trial of eating tremella for skin was found.
Form and dose studied
The human test was a topical alcohol gel; the lab work used extracts and an isolated hyaluronic acid. None applies to eating tremella.
Who was studied
20 Thai volunteers (gel test)
Limits
Short-term moisture only; one of the lab studies came from authors linked to the company that makes the product tested.
Why researchers looked
The polysaccharides are water-holding sugar chains, and the extract is used in skin-care products.
Traditional use
Tremella is eaten in Asian cooking; skin use in the sources is as a cosmetic ingredient.
Proposed mechanism Laboratory research
In human skin cells in a dish, a commercial extract raised DNA and collagen production and closed a scratch wound fastest at the higher strength. A separate lab model of fungal-derived hyaluronic acid from tremella found it stable and absorbed by gut cells. These are lab findings.
A proposed mechanism does not show that the effect happens in people.
The gel was not irritating in the 20 volunteers. Allergies to any skin product are possible.
Immune and antioxidant effects (lab and animal work)
Not enough evidenceReviews list immune-modulating, antioxidant and anti-inflammatory effects among reported activities of tremella polysaccharides. The reviews do not separate people from cells and animals, and no human trial of these effects was found.
3 studiesReviews cover purified polysaccharides, not the food.
Studies, doses and limits
Results
No human results.
Why this rating
Lab and animal findings only, as far as the abstracts say.
Form and dose studied
Reviews cover purified polysaccharides, not the food.
Limits
The review abstracts do not say how many of the findings came from people.
Why researchers looked
Many mushroom polysaccharides act on immune cells in the lab, so tremella has been tested the same way.
Traditional use
Reviews describe tremella as used as a food and medicinal ingredient in traditional Chinese medicine.
Proposed mechanism Laboratory research
Reviews list the effects as reported bioactivities of the polysaccharides, without detail on the cell or animal models.
A proposed mechanism does not show that the effect happens in people.
Not applicable.
Cholesterol and blood sugar (reported in reviews)
Not enough evidenceReviews list blood-sugar-lowering and cholesterol-lowering effects among reported activities. The only human tremella trial for blood sugar found a tiny change. No human cholesterol trial was found.
2 studiesNot applicable
Studies, doses and limits
What the trials found
No human cholesterol trial was found. See the prediabetes entry for the single small blood-sugar trial.
Why this rating
No human cholesterol data; reviews do not separate animal findings.
Limits
Review abstracts only.
Why researchers looked
Mushroom polysaccharides are often tested for sugar and fat handling.
Traditional use
Not described in the sources we read.
Proposed mechanism Unknown
Not separated by the review abstracts.
A proposed mechanism does not show that the effect happens in people.
Not applicable.
Connections to the rest of health
How Tremella 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 |
|---|---|---|---|---|
| Memory Support | Preliminary mechanism | Low certainty | Memory and thinking complaints: One 8-week trial in 75 adults with memory complaints found better scores on a memory questionnaire and some thinking tests with a tremella supplement than with placebo. A second trial used a drink that mixed fish roe, snow fungus and yeast, so it cannot be credited to tremella alone. Neither has been repeated. | 1 7 |
| Brain Health | Preliminary mechanism | Low certainty | Memory and thinking complaints: One 8-week trial in 75 adults with memory complaints found better scores on a memory questionnaire and some thinking tests with a tremella supplement than with placebo. A second trial used a drink that mixed fish roe, snow fungus and yeast, so it cannot be credited to tremella alone. Neither has been repeated. | 1 7 |
| Healthy Skin | Preliminary mechanism | Very low certainty | Skin moisture and skin care: Snow fungus polysaccharide is used in creams because it holds water. In a small test, a hand gel with the extract moistened skin better than a placebo gel for up to 3 hours. Most other skin findings are from cells and animals. Nobody has tested whether eating tremella changes the skin. | 8 13 12 10 |
| Immune Support | Preliminary mechanism | Not enough evidence | Immune and antioxidant effects (lab and animal work): Reviews list immune-modulating, antioxidant and anti-inflammatory effects among reported activities of tremella polysaccharides. The reviews do not separate people from cells and animals, and no human trial of these effects was found. | 14 6 9 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Brain Focus | Biological association | Low certainty | Studied for: Memory and thinking complaints | 1 7 |
| Nervous System | Biological association | Low certainty | Studied for: Memory and thinking complaints Studied for: Anxiety, tiredness and quality of life (mixture only) | 1 7 |
| Endocrine System | Biological association | Very low certainty | Studied for: Blood sugar markers and waist size in prediabetes | 4 14 6 |
| Integumentary System | Biological association | Very low certainty | Studied for: Skin moisture and skin care | 8 13 12 10 |
| Immune System | Biological association | Not enough evidence | Studied for: Immune and antioxidant effects (lab and animal work) | 14 6 9 |
| Cardiovascular System | Biological association | Not enough evidence | Studied for: Cholesterol and blood sugar (reported in reviews) | 14 6 |
C. Body parts and organs
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Liver | Adverse effect or risk | Low certainty | Severe poisoning from spoiled fungi damages liver, kidneys and brain. Preparation or compound: Bongkrekic acid from spoiled fungi, not tremella itself |
2 5 |
| Kidneys | Adverse effect or risk | Low certainty | Kidney damage in severe poisoning. Preparation or compound: Bongkrekic acid from spoiled fungi |
2 5 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Subjective memory complaint questionnaire score | Biological association | Low certainty | Measured in trials: improved. A lab change is not the same as a health benefit. | 1 |
| Short-term memory and executive-function tests | Biological association | Low certainty | Measured in trials: improved. A lab change is not the same as a health benefit. | 1 7 |
| Brain scan gray matter volume (exploratory) | Biological association | Very low certainty | Measured in trials: mixed. A lab change is not the same as a health benefit. | 1 |
| HbA1c (average blood sugar over about 3 months) | Biological association | Very low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 4 |
| Waist circumference | Biological association | Very low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 4 |
| Skin moisture (topical gel) | Biological association | Very low certainty | Measured in trials: raised. A lab change is not the same as a health benefit. | 8 |
J. Genes, receptors and enzymes
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| CD44 | Preliminary mechanism | In vitro | Hyaluronan receptor raised in a lab model of fungal hyaluronic acid. | 12 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Tremella polysaccharides (TFPs) | Biological association | In vitro | Reviews call them the main bioactive constituents and list immune, antioxidant, blood-sugar, gut-microbe and skin-related activities, mostly from lab and animal work. Preparation or compound: Fruiting body and fermentation products |
6 14 9 |
| Fungal-derived hyaluronic acid | Biological association | In vitro | One company-linked lab study reports a hyaluronic-acid-type molecule extracted from the fungus that is stable in simulated digestion. This chemistry was not independently verified here. Preparation or compound: Extract |
12 |
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 25, 2026).
The evidence
The research centre for Tremella. 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 read PubMed records and abstracts for 17 papers (three trials, one small gel test, six reviews, one surveillance study, two fungi-sampling studies, one outbreak report, one case report, two lab studies) and listed one more 1988 paper from its title only because it has no abstract. We checked the species name in GBIF. Only abstracts were read, so numbers come from abstracts. Certainty ratings are the compiler's own reading. EMA, FDA, EFSA, LiverTox, LactMed and WHO were not read.
Study library: every study we checked 20
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Ban 2018 Efficacy and Safety of Tremella fuciformis in Individuals with Subjective Cognitive Impairment: A Randomized Controlled Trial. Journal of Medicinal Food · PMID 29319408 · DOI |
Controlled trial |
75 75 adults with subjective cognitive impairment (memory complaints) |
Tremella fuciformis supplement (two daily amounts versus placebo) Not shown here 8 weeks · vs Placebo |
The Tremella groups improved more than placebo on the memory complaint questionnaire total score, and more on short-term memory and executive-function tests. An exploratory brain-scan analysis found group-by-visit differences in four brain areas. Adverse events were about equally common in the high-dose group (40.4%), low-dose group (35.1%) and placebo group (41.4%). Better questionnaire score and test results than placebo after 8 weeks; adverse events similar to placebo Methods, limits and fundingOutcomes: Subjective memory complaint questionnaire (main); short-term memory and executive-function tests; brain scans (gray matter volume, exploratory); adverse events Limitations: Small trial (only 15 people on placebo), 8 weeks, one product; the abstract does not say whether the product was fruiting body or mycelium, and the abstract gives no effect sizes. No funding statement was in the record. Not repeated in the sources read. Funding and conflicts: No funding or conflict statement in the PubMed record Read: abstract |
| Chen 2025 Forensic Research Progress on Bongkrekic Acid Poisoning. Fa Yi Xue Za Zhi (Journal of Forensic Medicine) · PMID 40813078 · DOI |
Narrative review review |
Review of autopsy cases and literature on bongkrekic acid poisoning | Bongkrekic acid Not shown here |
The review says bongkrekic acid is a stable toxin with no distinctive smell, found in fermented grain foods, potato products, spoiled tremella and wood ear, and in wood ear soaked too long. It says no specific antidote has been found and that poisoning is easy to miss, with a high death rate. It describes damage to liver, kidney, brain and other organs through blocking energy production in cells. No smell, no antidote, organ damage Methods, limits and fundingOutcomes: Sources, effects, detection Limitations: Review of forensic literature; no case counts in the abstract. Funding and conflicts: No conflict statement in the record Read: abstract |
| Gao 2025 Detection methods and control measures of Burkholderia gladioli and its toxins: A review. Journal of Food Science · PMID 39902981 · DOI |
Narrative review review |
Review of the bacterium that makes bongkrekic acid and toxoflavin | Burkholderia gladioli toxins fermented cereal products, spoiled fresh Tremella and Auricularia auricula, fermented potatoes Not shown here |
The review says the bacterium can make toxins in foods such as fermented cereal products, spoiled fresh Tremella and Auricularia auricula, and fermented potatoes. It says poisoning can cause diarrhoea and, in severe cases, convulsions and shock. Spoiled fresh tremella named as a source; diarrhoea, convulsions, shock Methods, limits and fundingOutcomes: Sources, symptoms, detection and control Limitations: Abstract only; no case numbers. Funding and conflicts: Research grant on the bacterium (per the record) Read: abstract |
| Gitsomboon 2024 Tremella fuciformis beverage improves glycated hemoglobin A1c and waist circumference in overweight/obese prediabetic subjects: a randomized controlled trial. BMC Nutrition · PMID 38439104 · DOI |
Controlled trial |
56 56 overweight or obese adults with prediabetes (Thailand) |
Tremella fuciformis beverage once daily Not shown here 12 weeks · vs Placebo beverage |
After 12 weeks the Tremella group had a slightly lower HbA1c (6.03% to 5.96%, p = 0.047, Cohen's d = 0.39) and a smaller waist (95.2 to 93.46 cm, p = 0.022, Cohen's d = 0.45). No adverse events were reported. The authors call it an exploratory study and ask for larger trials. Very small changes in HbA1c and waist size; exploratory (HbA1c 6.03 to 5.96% (p = 0.047); waist 95.2 to 93.46 cm (p = 0.022)) Methods, limits and fundingOutcomes: Body measurements, blood sugar markers (HbA1c) and insulin sensitivity Limitations: Small trial, 12 weeks, exploratory; the abstract compares before and after within the Tremella group and does not state a between-group difference. A 0.07 percentage-point HbA1c change is small. The product is a beverage whose make-up the abstract does not describe. Funding and conflicts: Authors declare no competing interests Registration: Thai Clinical Trials Registry TCTR20210714004 Read: abstract |
| Hu 2024 Unexplained Rhabdomyolysis and Hepatic Renal Dysfunction: A Case of Bongkrekic Acid Poisoning. Cureus · PMID 39483585 · DOI |
Case report |
Patients with foodborne bongkrekic acid poisoning (case report) | Bongkrekic acid Not shown here |
The report says severe poisoning can quickly move from liver and kidney damage to multiple organ failure, and can rarely appear as lasting low blood sugar and muscle breakdown (rhabdomyolysis). It says the death rate is high and clinical data are limited. Fast organ failure; high death rate Methods, limits and fundingOutcomes: Clinical features Limitations: The abstract does not say which food was involved, so it is not tied to tremella. Funding and conflicts: No funding or conflicts declared Read: abstract |
| Li 2025 Recent advances in polysaccharides from Tremella fuciformis: isolation, structures, bioactivities and application. Frontiers in Nutrition · PMID 41346688 · DOI |
Narrative review review |
Review of the polysaccharides of snow fungus | Tremella fuciformis polysaccharides (TFPs) Not shown here |
The review lists gut-microbe balance, immune modulation, antioxidant, anti-high-blood-sugar and anti-high-blood-fats effects among reported activities of the polysaccharides. The abstract does not separate human from lab or animal work. List of reported activities, not human proof Methods, limits and fundingOutcomes: Reported bioactivities Limitations: The abstract does not say which results came from people. Funding and conflicts: Authors declare no commercial or financial relationships that could be a conflict of interest Read: abstract |
| Lin 2023 Effectiveness of Fish Roe, Snow Fungus, and Yeast Supplementation for Cognitive Function: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. Nutrients · PMID 37836504 · DOI |
Controlled trial |
64 64 adults with subjective cognitive complaints |
Combination drink containing fish roe, snow fungus and yeast Not shown here 8 weeks · vs Placebo drink |
At 4 and 8 weeks the formula group remembered more memory cards and responded faster than placebo. The cue effect of happy faces rose at 8 weeks. Anxiety and fatigue fell and quality of life improved. The abstract gives no numbers. Better scores on several cognitive tests and mood measures with a three-ingredient drink Methods, limits and fundingOutcomes: Cognitive tests at weeks 0, 4 and 8 (memory cards, response times, facial-expression cue effect); anxiety, fatigue and quality of life Limitations: This was a combination of fish roe, snow fungus and yeast, so no result can be credited to snow fungus alone. No figures in the abstract. Small and short. Funding and conflicts: Supported by an industry-university cooperation programme (per the record); authors declare no conflict of interest Read: abstract |
| Lourith 2021 Formulation and efficacy evaluation of the safe and efficient moisturizing snow mushroom hand sanitizer. Journal of Cosmetic Dermatology · PMID 32531816 · DOI |
Non randomised human study |
20 20 Thai volunteers |
Alcohol-based hand gel with snow mushroom polysaccharide extract, applied to the skin Not shown here Measured up to 180 minutes · vs Placebo gel |
The gel with the mushroom extract was not irritating, like the placebo gel, and moistened the skin better than the placebo at every time point up to 180 minutes (P < .05). The germ-killing action of the active and placebo gels was similar. Short-term skin moisture better than a placebo gel (P < .05 at all time points) Methods, limits and fundingOutcomes: Skin moisture, skin irritation and germ-killing action of the gel Limitations: Applied to the skin in an alcohol gel, not eaten. 20 people, 180 minutes, no figures in the abstract. It does not show lasting skin benefit and says nothing about eating the mushroom. Funding and conflicts: No funding or conflict statement in the record Read: abstract |
| Luan 2026 Research progress in polysaccharides from the Tremella fuciformis (silver ear): extraction, purification, structural features, health-promoting activities, and potential applications. International Journal of Biological Macromolecules · PMID 42019856 · DOI |
Narrative review review |
Review of silver ear polysaccharides | Tremella fuciformis polysaccharides (TFPs) Not shown here |
The review lists many reported activities (immune, antioxidant, gut, blood sugar, liver, nerve protection and others) and says use in foods and health products is limited by weak understanding of structure-activity links, applications and safety profiles. Reported activities; safety profile called poorly understood Methods, limits and fundingOutcomes: Reported activities, structure, safety evaluation Limitations: Abstract only; does not separate human from lab or animal findings. Funding and conflicts: No competing interests declared Read: abstract |
| Mineroff 2023 The potential cutaneous benefits of Tremella fuciformis. Archives of Dermatological Research · PMID 36757441 · DOI |
Narrative review review |
Narrative review of skin research on snow mushroom extract | Tremella fuciformis polysaccharide extract Not shown here |
The authors say studies point to roles in skin anti-ageing, sun protection, wound healing and barrier protection, but most studies were in cell cultures (in vitro) and animals. They say clinical research is needed. Mostly lab and animal findings Methods, limits and fundingOutcomes: Skin anti-ageing, photoprotection, wound healing and barrier protection Limitations: Narrative review; the abstract does not give study counts or numbers. Funding and conflicts: No funding or conflict statement in the record Read: abstract |
| Si 1988 [A report of 25 cases of deteriorated tremella poisoning] Zhonghua Yu Fang Yi Xue Za Zhi (Chinese Journal of Preventive Medicine) · PMID 3234173 |
Case series |
25 25 people poisoned by deteriorated tremella (per the title) |
Deteriorated tremella fruiting body |
Only the title was read. It reports 25 cases of poisoning from deteriorated tremella; no further detail is claimed here. Methods, limits and fundingOutcomes: Not available: the PubMed record has no abstract Limitations: No abstract; title and record only. English abstract is not available in the record. Funding and conflicts: Not stated Read: record only (title; no abstract) |
| Uberti 2026 Absorption, Stability, and Bioactivity of Fungal-Derived Hyaluronic Acid from Tremella fuciformis in a Sequential In Vitro Multi-Barrier Model. Foods · PMID 41976431 · DOI |
Laboratory research cells |
Layered cell models of gut, liver, kidney, cartilage and skin cells | Fungal-derived hyaluronic acid extracted from Tremella fuciformis Not shown here Cell models · vs Sodium hyaluronate |
In the lab models the fungal hyaluronic acid kept its structure through simulated digestion, crossed a gut-cell barrier and showed more antioxidant and anti-inflammatory activity than sodium hyaluronate. The authors conclude it is stable and bioactive in these models. Lab models only Methods, limits and fundingOutcomes: Stability, passage across gut cells, antioxidant and anti-inflammatory activity Limitations: No people or animals. Two authors work for the company that makes the product tested and the founder is a company owner; the company paid for reagents. This is one product, not the mushroom. Funding and conflicts: Company-linked (Noivita Srls) per the authors' statement Read: abstract |
| Wolosik 2026 Tremella fuciformis Extract Evokes Similar Effect as Hyaluronic Acid on Wound Healing but Through Different Mechanisms in Human Dermal Fibroblasts. Molecules · PMID 42451721 · DOI |
Laboratory research cells |
Human skin fibroblast cells grown in the lab | Commercial Tremella fuciformis extract compared with hyaluronic acid Not shown here Cell culture · vs Hyaluronic acid |
The extract did not change cell survival. It raised DNA production at both strengths and collagen production at the higher strength, and closed the scratch fastest at the higher strength. Some signalling markers (p-AKT) rose. The authors call parts of the data descriptive and say more work is needed. Cell-culture findings only Methods, limits and fundingOutcomes: Cell survival, DNA and collagen production, scratch-wound closure and signalling markers Limitations: Cells in a dish, not people. The authors say parts of the data are descriptive because samples were pooled. Funding and conflicts: University funding (Medical University of Bialystok); authors declare no conflicts of interest Read: abstract |
| Wu 2019 Structure, bioactivities and applications of the polysaccharides from Tremella fuciformis mushroom: A review. International Journal of Biological Macromolecules · PMID 30342120 · DOI |
Narrative review review |
Review of the structure and reported bioactivities of the mushroom's polysaccharides | Tremella fuciformis polysaccharides (TPS) fruiting body and other sources, not specified Not shown here |
The review lists anti-tumour, immune-modulating, antioxidant, anti-ageing, memory-repairing, anti-inflammatory, blood-sugar-lowering and cholesterol-lowering effects as reported for the polysaccharides. The abstract does not separate cell, animal and human findings. List of reported activities, not human proof Methods, limits and fundingOutcomes: Reported bioactivities Limitations: The abstract does not say how many findings came from people, so none can be treated as human evidence. Funding and conflicts: No conflict statement in the record Read: abstract |
| Xiao 2025 Isolation and Identification of Burkholderia gladioli pathovar cocovenenans from Black Fungus and Characteristics of the Bon Gene Cluster - Shanghai Municipality, China, 2023. China CDC Weekly · PMID 40620660 · DOI |
Food sampling study bacteria |
85 85 samples of commercially available fungi in Shanghai |
Bacteria that can make bongkrekic acid, tested for in fungi samples fresh and dried tremella and black fungus Not shown here 2023 sampling |
Burkholderia gladioli was found in 44.7% of the 85 samples. Detection was highest in dried black fungus (94.4%), then fresh Tremella fuciformis (16.6%), fresh black fungus (9.1%) and dried T. fuciformis (3.8%). The toxin-making pathovar (cocovenenans) was found only in dried black fungus (39%). The authors advise people to avoid eating fungi products soaked for 24 hours or more, at any temperature. B. gladioli found in 16.6% of fresh and 3.8% of dried tremella samples; toxin-making pathovar only in dried black fungus Methods, limits and fundingOutcomes: Share of samples with Burkholderia gladioli, and the toxin-making pathovar Limitations: One city and one year, small sample number per type (the abstract does not give them). Finding the bacterium is not the same as finding the toxin. Funding and conflicts: No conflicts of interest declared Read: abstract |
| Yao 2024 Exploring the characteristics of Burkholderia gladioli pathovar cocovenenans: Growth, bongkrekic acid production, and potential risks of food contamination in wet rice noodles and vermicelli. Food Microbiology · PMID 38431336 · DOI |
Food sampling study bacteria |
482 482 samples of wet rice and starch products, Tremella and Auricularia in Guangzhou |
Toxin-making bacteria and bongkrekic acid in foods tremella and wood ear were among the foods sampled Not shown here |
Three of the 482 samples (0.62%) were positive for the toxin-making pathovar. In wet rice noodles, toxin levels rose at 26 and 32 degrees C and were held back at 4 and -18 degrees C. The abstract does not say which food types the three positives were. Rare in samples (3 of 482); warm storage raised toxin in noodles Methods, limits and fundingOutcomes: Detection rate; effect of storage temperature (in noodles) Limitations: The temperature experiments were done in rice noodles and vermicelli, not in tremella. Breakdown by food type is not in the abstract. Funding and conflicts: No conflicts of interest declared Read: abstract |
| Yuan 2020 A Foodborne Bongkrekic Acid Poisoning Incident - Heilongjiang Province, 2020. China CDC Weekly · PMID 34594817 · DOI |
Outbreak report |
9 9 people in one outbreak (homemade fermented corn flour 'sour soup') |
Bongkrekic acid in a homemade fermented corn flour food Not shown here 2020 outbreak |
All 9 people who ate the sour soup died (case fatality 100%). Bongkrekic acid was found in food and body samples. The report says that eating fermented corn flour products, deteriorated fresh tremella or black fungus, and spoiled starch products may cause bongkrekic acid poisoning, and that foods kept for a long time should not be eaten. Fatal outbreak; public health advice not to eat food kept for a long time Methods, limits and fundingOutcomes: Toxin levels in food and body samples; deaths Limitations: The food in this outbreak was a corn flour product, not tremella. Tremella is named only in the report's general warning. Funding and conflicts: No conflict statement in the record Read: abstract |
| Zhang 2023 Epidemiology of foodborne bongkrekic acid poisoning outbreaks in China, 2010 to 2020. PLoS ONE · PMID 36630445 · DOI |
Surveillance |
19 foodborne bongkrekic acid outbreaks reported to China's national surveillance system, 2010-2020 | Bongkrekic acid (a bacterial toxin) in foods including tremella Not shown here 2010-2020 |
There were 19 outbreaks with 146 illnesses, 139 hospitalisations and 43 deaths (case-fatality 29.5%). About 73.3% of outbreaks were in South and Southwest China. Homemade fermented corn flour products, tremella, and sweet potato and corn flour jelly caused more of the early outbreaks; wet rice noodles and Auricularia (wood ear) were linked to later ones. Most happened at home (79.0%). Banning homemade fermented corn flour products and better early treatment were followed by a lower case-fatality rate. 19 outbreaks, 43 deaths; tremella named as one of several foods Methods, limits and fundingOutcomes: Illnesses, hospital stays, deaths, foods involved Limitations: Surveillance of reported outbreaks, so it counts only what was reported. The abstract does not give a separate tremella count. Funding and conflicts: Government surveillance research support (non-US government) per the record Read: abstract |
| n/a 2025 China CDC Weekly reports on bongkrekic acid poisoning (Heilongjiang 2020; Shanghai fungi sampling 2023) China CDC Weekly · Source |
Authoritative guidance n/a |
n/a | n/a |
The 2020 report says foods kept for a long time should not be eaten and homemade fermented starch foods should be avoided. The 2025 report advises avoiding fungi products soaked for 24 hours or more, at any temperature. Abstracts read only; this page does not say these are official regulations. Methods, limits and fundingOutcomes: Public-health advice from the Chinese Center for Disease Control and Prevention's journal Limitations: These are journal reports by public-health scientists. No US, EU or UK regulator statement on tremella was read. Funding and conflicts: Public health agency journal Read: abstracts of the two reports (see their own entries) |
| n/a 2026 GBIF Backbone Taxonomy: Tremella fuciformis Berk. (usage key 5237434) n/a · Source |
Taxonomy record fungus |
n/a | n/a |
GBIF lists Tremella fuciformis Berk. as an ACCEPTED species (exact match) in kingdom Fungi, phylum Basidiomycota, class Tremellomycetes, order Tremellales, family Tremellaceae. Methods, limits and fundingOutcomes: Accepted species name, authority and place in the fungal tree Limitations: Index Fungorum was not opened. A taxonomy record says nothing about health effects. Funding and conflicts: Public database Read: API response read on 2026-10-25 |
What we do not know yet
- The memory result has not been repeated, and the abstracts do not say whether the product was fruiting body or mycelium.
- No human trial of tremella for skin (eaten), immune function or cholesterol was found.
- No data on medicine interactions, pregnancy, breastfeeding, children, allergy or long-term use.
- Poisoning reports group several foods; tremella-only counts are not given in the abstracts read.
- No regulator statement, heavy-metal or product-quality test was read.
How new research is added
New studies are found by a saved PubMed search and placed in a review queue. A person reads each one before it changes any evidence rating or safety wording. New publications never change ratings automatically.
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 1
HbA1c (average blood sugar over about 3 months)
Lowered in trials
A blood test that reflects average blood sugar over the last 2 to 3 months. Lower means better control.
Very low certaintyResults and what it means
Why it was measured
Standard marker for prediabetes and diabetes.
Statistical vs. clinical meaning
Statistically significant by the authors' test, but only 0.07 percentage points.
Safety implication
No adverse events reported.
| Study | Result | People | Product |
|---|---|---|---|
| 4 | 6.03% at the start to 5.96% at 12 weeks in the tremella group (p = 0.047, Cohen's d 0.39). | 56 overweight or obese adults with prediabetes | Tremella fuciformis beverage versus placebo, 12 weeks |
Other 5
Subjective memory complaint questionnaire score
Improved in trials
A questionnaire in which people rate how much they notice memory problems in daily life. A better score means fewer complaints, not a repaired memory.
Low certaintyResults and what it means
Why it was measured
It was the main outcome of the tremella trial.
Statistical vs. clinical meaning
Reported as greater than placebo; the abstract gives no effect size or P value.
Safety implication
Adverse events were similar to placebo.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | Greater improvement in total score than placebo after 8 weeks (no figures in the abstract). | 75 adults with subjective cognitive impairment | Tremella fuciformis supplement (two amounts) versus placebo, 8 weeks |
Short-term memory and executive-function tests
Improved in trials
Standard computer or paper tests of remembering new information and planning or switching between tasks.
Low certaintyResults and what it means
Why it was measured
Used to check whether the questionnaire change was matched by test performance.
Statistical vs. clinical meaning
Better than placebo in both trials, one of them a mixture.
Safety implication
Not described beyond the trials' general safety reports.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | Significantly greater improvement than placebo in short-term memory and executive functions (no figures in the abstract). | 75 adults with subjective cognitive impairment | Tremella fuciformis supplement versus placebo, 8 weeks |
| 7 | More memory cards remembered and faster responses than placebo at 4 and 8 weeks, with a three-ingredient drink (no figures in the abstract). | 64 adults with subjective cognitive complaints | Fish roe, snow fungus and yeast drink versus placebo, 8 weeks |
Brain scan gray matter volume (exploratory)
Mixed results in trials
A brain scan method that compares how much gray matter is measured in different brain areas.
Very low certaintyResults and what it means
Why it was measured
The trial team used it as an exploratory look at brain changes.
Statistical vs. clinical meaning
Exploratory only. A scan difference does not show better memory or a lasting brain change.
Safety implication
None described.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | Group-by-visit differences were found in the left precuneus, right supramarginal gyrus, right middle frontal gyrus and right postcentral gyrus (corrected P < .05). | 75 adults with subjective cognitive impairment | Tremella fuciformis supplement versus placebo, 8 weeks |
Waist circumference
Lowered in trials
The distance around the waist, used as a rough sign of belly fat.
Very low certaintyResults and what it means
Why it was measured
A simple measure of body fat distribution.
Statistical vs. clinical meaning
About 1.7 cm smaller. One small exploratory trial.
Safety implication
No adverse events reported.
| Study | Result | People | Product |
|---|---|---|---|
| 4 | 95.2 cm at the start to 93.46 cm at 12 weeks in the tremella group (p = 0.022, Cohen's d 0.45). | 56 overweight or obese adults with prediabetes | Tremella fuciformis beverage versus placebo, 12 weeks |
Skin moisture (topical gel)
Raised in trials
How much water the outer skin holds, measured on the skin surface after applying a product.
Very low certaintyResults and what it means
Why it was measured
The main claim for tremella in skin care is water-holding.
Statistical vs. clinical meaning
Short-term effect of a topical product; does not apply to eating tremella.
Safety implication
Not irritating in the 20 volunteers.
| Study | Result | People | Product |
|---|---|---|---|
| 8 | Skin moistened better than with a placebo gel at all times up to 180 minutes (P < .05). | 20 Thai volunteers | Alcohol hand gel with snow mushroom extract versus placebo gel |
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 3
- Spoiled or long-soaked tremella can carry a deadly bacterial toxin. Tremella and black fungus (wood ear) that have gone bad, or have been left soaking for a long time, can grow bacteria that make bongkrekic acid. A forensic review calls the toxin stable, with no distinctive smell, and says no specific antidote has been found. In China from 2010 to 2020, 19 outbreaks caused 146 illnesses and 43 deaths. The foods involved included fermented corn flour products, tremella and starch jellies, and later wet rice noodles and wood ear. The authors of a 2025 Shanghai study advise not eating fungi products soaked for 24 hours or more. This is a food-spoilage danger, not an effect of properly stored tremella. Authoritative guidance 18 2 15 17 3 11
- Little is known about medicine interactions, pregnancy, breastfeeding or long-term use. None of the sources we read tested tremella with medicines, in pregnancy, breastfeeding or children, or beyond 12 weeks. Food use is long-standing in Asia, but that is not a safety test of concentrated extracts. Unknown 1 4 9
- In the two trials of tremella alone, side effects were not more common than with placebo. In the 8-week memory trial, adverse events were 40.4% (high amount), 35.1% (low amount) and 41.4% (placebo). The 12-week prediabetes trial reported no adverse events. Both were small. Controlled trial 1 4
Side effects 4
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Poisoning from spoiled tremella (bongkrekic acid): diarrhoea, convulsions, shock, liver, kidney and brain damage Applies to spoiled or long-soaked fungi, not to fresh tremella that is stored and cooked properly. | 19 outbreaks in China 2010-2020, 146 illnesses, 43 deaths (all foods, not only tremella) | life-threatening Often fatal; no specific antidote | Surveillance 18 3 2 |
| Muscle breakdown (rhabdomyolysis), low blood sugar and liver and kidney failure in severe bongkrekic acid poisoning The case report abstract does not say which food was eaten. | Case report; no rate | severe High mortality reported | Case report 5 |
| Adverse events in the tremella supplement trial Types of events are not listed in the abstract. | 35.1% to 41.4% across groups, similar to placebo | not described in the abstract Not described | Controlled trial 1 |
| Skin irritation from a tremella extract hand gel Small test of a topical gel. | None seen in 20 volunteers | none observed Not applicable | Human study 8 |
Liver
No report of liver injury from properly stored tremella was found in the sources read. Severe bongkrekic acid poisoning from spoiled fungi damages the liver, kidneys and brain (forensic review) and can progress to multiple organ failure (case report). 5 2
How often. No rate for liver problems from tremella products was found.
Monitoring. No monitoring advice was read.
- p39483585.
This is a safety connection. It is not evidence that Tremella supports liver health.
Medicines and supplements 4
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Blood-sugar-lowering medicines (for diabetes) prescription | Reviews list blood-sugar-lowering among reported activities (not separated into human and animal); a small trial saw a tiny HbA1c change. | No interaction study was found. | Theoretical Not enough evidence 14 4 | If you take diabetes medicines, ask your doctor or pharmacist before using tremella supplements. |
| Blood thinners, immune-suppressing medicines and other prescription drugs prescription | No data found. | No source read describes an interaction or says there is none. | Unknown Not enough evidence 9 | Tell your pharmacist about any supplement you take, as with any new product. |
| Herbs and other supplements herb-supplement | No data found. | One cognition trial used tremella mixed with fish roe and yeast, but it did not test interactions. | Unknown Not enough evidence 7 | Ask a pharmacist if you use several supplements. |
| Food and alcohol food | No data found. | No source read. | Unknown Not enough evidence | None specific. |
Who should check first 6
| Situation | Advice | Evidence |
|---|---|---|
| Any tremella or black fungus that is slimy, sour-smelling, discoloured or has been soaked or kept a long time | Do not eat it. Throw it away. The toxin has no distinctive smell, so a normal smell does not prove it is safe. | Authoritative guidance 2 15 17 |
| Pregnancy | No safety data were found in the sources read. Ask a doctor or midwife before using tremella supplements; ordinary food use is a separate question. | Unknown |
| Breastfeeding | No data found in the sources read. Ask a doctor. | Unknown |
| Children | No trials in children were found. Ask a doctor before giving supplements. | Unknown |
| Diabetes or blood-sugar medicines | Ask your doctor or pharmacist before using tremella supplements. | Theoretical 14 4 |
| Mushroom allergy | No allergy report for tremella was found in the sources read. If you react to mushrooms, take care and ask a doctor. | Unknown |
Overdose, product quality and regulators
Summary. The main poisoning risk found is from bacteria growing on spoiled or long-soaked fungi, which make bongkrekic acid. No poisoning from properly stored tremella itself was found in the sources read.
Animal. Not reviewed.
Human doses studied. Trials ran 8 and 12 weeks. This page does not give amounts, and none are advised.
High dose or long term signals. Long-term safety beyond 12 weeks is not known. A 2026 review says the safety profile of the polysaccharides is poorly understood.
Overdose response. For suspected poisoning from spoiled fungi, seek emergency care at once. No specific antidote is known (forensic review).
Genotoxicity. Not read.
Toxic or hazardous parts. Fungus: fruiting body is eaten. The danger found is bacterial toxin from spoilage, not a toxin made by the mushroom.
Spoilage bacteria are the main contamination issue found. Product quality, species and heavy-metal or pesticide testing were not covered by the sources read.
Bacteria that make bongkrekic acid on fungi. In Shanghai, Burkholderia gladioli was found in 16.6% of fresh and 3.8% of dried Tremella fuciformis samples; the toxin-making pathovar was found only in dried black fungus (39%). A Guangzhou survey found the toxin-making pathovar in 3 of 482 samples of rice and starch products, tremella and wood ear. 15 16
How long fungi stay in water. The Shanghai authors advise avoiding fungi products soaked for 24 hours or more, at any temperature. In rice noodle tests, cold storage (4 and -18 degrees C) held back toxin and warm storage raised it; that test was not done in tremella. 15 16
Which species is in the product. Tremella mesenterica (yellow brain) is a different species with its own page. Supplement labels may name the species, or the part used (fruiting body or mycelium), differently. No product test was read. 20
| Body | Action | Date |
|---|---|---|
| China CDC Weekly (Chinese Center for Disease Control and Prevention journal) (China) | Reports advise against eating foods kept for a long time and homemade fermented starch foods (2020) and against eating fungi products soaked for 24 hours or more (2025). source | 2025 |
When to get medical help
- After eating tremella or black fungus that was soaked or kept for a long time: vomiting, diarrhoea, severe belly pain, extreme weakness, muscle pain, dark urine, confusion, convulsions or fainting. Get emergency medical help now and say what was eaten.
- Several people ill after the same meal: seek emergency help for everyone and keep the food for testing if it is safe to do so.
If someone may be poisoned or in a crisis, contact a clinician or emergency service straight away. 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 tremella?
Can tremella be poisonous?
Properly stored tremella is a long-standing food, but tremella and black fungus that have spoiled or been soaked for a long time can carry bacteria that make bongkrekic acid. In China from 2010 to 2020, 19 outbreaks from several foods caused 43 deaths. The toxin has no distinctive smell and no specific antidote is known.
How can I keep tremella safe to eat?
What are the signs of poisoning from spoiled tremella?
Does tremella help memory?
Does tremella help blood sugar or weight?
One 12-week trial in 56 people with prediabetes saw HbA1c fall from 6.03% to 5.96% and waist size from 95.2 to 93.46 cm with a tremella drink. These are very small changes from one exploratory trial. It is not a treatment for diabetes.
Is tremella good for your skin?
A hand gel with tremella extract moistened skin better than placebo gel for up to 3 hours in 20 people. Most other findings are from cells and animals, and we found no human trial of eating tremella for skin. Collagen and hyaluronic acid claims in cell studies do not show a skin effect in people.
Does tremella boost the immune system?
Does tremella interact with medicines?
Is tremella safe in pregnancy or breastfeeding?
None of the sources we read tested it in pregnancy, breastfeeding or children. Ask a doctor or midwife before using supplements.
Is snow fungus the same as tremella?
Is fungal hyaluronic acid from tremella proven to work?
No. The evidence read is one lab study of a fungal-derived hyaluronic acid in cell models, and the authors are linked to the company that makes the product.
Explore by health goal
Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against PubMed records.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-25
- Last substantive update
- 2026-10-25
- How we research
- We read PubMed records and abstracts for 17 papers (three trials, one small gel test, six reviews, one surveillance study, two fungi-sampling studies, one outbreak report, one case report, two lab studies) and listed one more 1988 paper from its title only because it has no abstract. We checked the species name in GBIF. Only abstracts were read, so numbers come from abstracts. Certainty ratings are the compiler's own reading. EMA, FDA, EFSA, LiverTox, LactMed and WHO were not read.
- 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. This page is information, not a recommendation to use tremella.
Sources 20
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Ban S, Lee SL, Jeong HS, et al. Efficacy and Safety of Tremella fuciformis in Individuals with Subjective Cognitive Impairment: A Randomized Controlled Trial.. Journal of Medicinal Food. 2018. PMID 29319408. DOI 10.1089/jmf.2017.4063. (abstract)
- Chen XL, Yuan Q, Sun Y, et al. Forensic Research Progress on Bongkrekic Acid Poisoning.. Fa Yi Xue Za Zhi (Journal of Forensic Medicine). 2025. PMID 40813078. DOI 10.12116/j.issn.1004-5619.2024.440206. (abstract)
- Gao B, Deng H, Wang Y, et al. Detection methods and control measures of Burkholderia gladioli and its toxins: A review.. Journal of Food Science. 2025. PMID 39902981. DOI 10.1111/1750-3841.17668. (abstract)
- Gitsomboon S, Ratanapornsompong G, Ongphiphadhanakul B, et al. Tremella fuciformis beverage improves glycated hemoglobin A1c and waist circumference in overweight/obese prediabetic subjects: a randomized controlled trial.. BMC Nutrition. 2024. PMID 38439104. DOI 10.1186/s40795-024-00842-0. (abstract)
- Hu R, Fu T, Xia S, et al. Unexplained Rhabdomyolysis and Hepatic Renal Dysfunction: A Case of Bongkrekic Acid Poisoning.. Cureus. 2024. PMID 39483585. DOI 10.7759/cureus.70625. (abstract)
- Li S, Zhao K, Li J, et al. Recent advances in polysaccharides from Tremella fuciformis: isolation, structures, bioactivities and application.. Frontiers in Nutrition. 2025. PMID 41346688. DOI 10.3389/fnut.2025.1663327. (abstract)
- Lin YK, Lin YH, Chiang CF, et al. Effectiveness of Fish Roe, Snow Fungus, and Yeast Supplementation for Cognitive Function: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.. Nutrients. 2023. PMID 37836504. DOI 10.3390/nu15194221. (abstract)
- Lourith N, Pungprom S, Kanlayavattanakul M. Formulation and efficacy evaluation of the safe and efficient moisturizing snow mushroom hand sanitizer.. Journal of Cosmetic Dermatology. 2021. PMID 32531816. DOI 10.1111/jocd.13543. (abstract)
- Luan F, Guo H, Lei Z, et al. Research progress in polysaccharides from the Tremella fuciformis (silver ear): extraction, purification, structural features, health-promoting activities, and potential applications.. International Journal of Biological Macromolecules. 2026. PMID 42019856. DOI 10.1016/j.ijbiomac.2026.152150. (abstract)
- Mineroff J, Jagdeo J. The potential cutaneous benefits of Tremella fuciformis.. Archives of Dermatological Research. 2023. PMID 36757441. DOI 10.1007/s00403-023-02550-4. (abstract)
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- n/a. GBIF Backbone Taxonomy: Tremella fuciformis Berk. (usage key 5237434). n/a. 2026. (API response read on 2026-10-25)
Where to buy
Check the label first. Whatever you buy, look for these:
- Fruiting body versus mycelium on grain: the label should say which
- The extract type and the beta-glucan amount, if stated
- A third-party testing mark
- Interactions: ask a pharmacist if you take medicines or blood thinners
Talk to a pharmacist or doctor before you start any supplement, especially if you take medicines. See the Safety tab for interactions.
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