Mulberry Leaf Tea: What Research Shows About the Tea, Safety and Cautions
Mulberry leaf tea: what small blood sugar trials of the tea show, how it differs from extracts, and cautions for diabetes medicines, pregnancy and mulberry allergy.
Content last updated . This page has not been medically reviewed.
Safety first. Natural products can cause side effects and interact with medicines. Read herbal tea and extract safety before you use anything on this page.
Check before you drink: ask first if you take diabetes medicine, are pregnant or breastfeeding, or have a mulberry allergy. NIH's complementary health center says white mulberry leaf may cause low blood sugar when taken with diabetes medicines, and that safety in pregnancy and breastfeeding is not well established. [1] A 2025 review lists mulberry allergy, including breathing symptoms, hives, mouth itching and, rarely, anaphylaxis. [7] Mulberry leaf tea is a herbal infusion (tisane) made from the leaf of a tree, not from the tea plant. This page covers the tea itself and keeps it apart from powders, capsules and concentrated extracts.
What mulberry leaf tea is
White mulberry (Morus alba) is native to China and now grows in temperate and tropical regions worldwide. [1] NIH says the leaves are used to make tea in parts of Asia and, in traditional Chinese medicine, for diabetes, cough, sore throat, fever and bronchitis. [1] Traditional use is history, not proof. The berries, bark and twigs are different parts with different research; NIH says safety information on the berries is insufficient. [1] For the supplement-level page see the mulberry leaf guide.Taste, caffeine and how to brew
| Question | What sources say |
|---|---|
| Taste | Proper evidence not found in the sources we read. Many people describe it as mild, grassy and slightly sweet; that is a general description, not a sourced finding. |
| Caffeine per 8 fl oz (240 mL) cup | A 2024 review states that herbal teas do not contain caffeine, but it also lists caffeine in a few named teas, so this is a general statement and not a measurement of mulberry leaf. [9] |
| Water temperature and steeping time | Proper evidence not found in the sources we read. |
| Amount of leaf per cup | Proper evidence not found for a standard tea amount. In one trial, people took 3 g of a mulberry leaf and water chestnut husk tea with a rice meal; that tea contained 10.2 mg of the compound DNJ and 61.3 mg of total polyphenols per 3 g. [3] The abstract gives no water volume or brewing method, and this is not a recommendation. |
| Strength varies | A 2025 lab study of mulberry leaf infusions found total phenolics ranged 18.1 to 35.2 mg per 100 mL for commercial products and 19.7 to 52.6 mg for wild-collected leaves. [8] Products differ. |
| Cold brew / iced | Proper evidence not found in the sources we read. |
| Very hot drinks | Proper evidence not found that ties this tea to the hot-drink concern. See hot tea and esophageal cancer risk. |
What research found about the tea itself
Labels used: Promising but limited, Mixed, Insufficient evidence, Lab or animal only, Extract only. Note that the human tea trials we found used a blend of mulberry leaf with water chestnut, not plain mulberry leaf tea.| Question | What the source found | Strength of evidence | Form and who was studied |
|---|---|---|---|
| Blood sugar and insulin after rice | In 30 Japanese adults with borderline diabetes (double-blind crossover), 3 g of mulberry leaf and water chestnut husk tea with rice gave significantly lower blood glucose at 30 and 60 minutes and lower insulin through 120 minutes than placebo. [3] | Promising but limited | Blend tea; single meal; funded by a city grant |
| Blood sugar swings over 2 weeks | In 31 people (double-blind crossover, 2 weeks per period), a mulberry and water chestnut tea taken before meals lowered the variation in glucose compared with placebo (p = 0.0006) and 1-hour glucose area; there were no differences in low blood sugar, liver, kidney or inflammation markers. [2] | Promising but limited | Blend tea; funded by a city and university grants |
| Glucose after breakfast and lunch | In 20 healthy adults (crossover), the blend tea before breakfast lowered the glucose rise after breakfast and after lunch; the authors advise caution and confirmation. [4] | Promising but limited | Blend tea; healthy adults |
| Blood sugar and blood fats in rats | In rats with induced diabetes, white mulberry leaf tea for 4 weeks did not significantly improve blood glucose, but cholesterol, LDL and triglycerides were lower at the high dose. [5] | Lab or animal only | Rats, not people |
| HbA1c and long-term control, extract | A 2025 meta-analysis of 15 trials (1,202 adults with metabolic disorders) of mulberry extract reported improvements in fasting glucose and HbA1c, with different effects by plant part. [6] | Extract only | Extracts, not tea |
Limits: the tea trials are small (20 to 31 people), short, used a blend rather than plain leaf, and some were funded by local governments tied to the product. They measure blood sugar after meals, not diabetes complications. The extract analysis cannot be applied to a cup of tea. NIH sums up the research as limited, preliminary and sometimes finding no effect. [1]
Check before you drink
- Diabetes medicines. NIH says white mulberry may cause low blood sugar when taken with diabetes medicines. [1] The two-week tea trial found no difference in low blood sugar events versus placebo, but it was small and did not focus on people using medicine. [2] Ask a prescriber or pharmacist; do not change medicine on your own. See herbs and diabetes, blood pressure and heart medicines and herbal tea for people with diabetes or high blood pressure.
- Pregnancy and breastfeeding. NIH: safety is not well established. [1] NHS says there is little research on herbal teas in pregnancy and suggests limiting them. [10] See pregnancy teas to ask about and herbal tea and breastfeeding.
- Babies and children. Proper evidence not found for mulberry leaf tea in children in the sources we read. See herbal tea for babies and children.
- Side effects. NIH says studies up to 12 weeks reported no serious harm; the most common effect is digestive upset such as bloating, constipation, gas and loose stools. [1]
- Allergy. A 2025 review lists mulberry allergy including respiratory allergy, hives on contact, oral allergy syndrome, anaphylaxis and food-triggered hives. [7] Severe reactions are an emergency; in the US, call 911. See herbal tea allergy and cross-reactions.
- Liver and kidney. The two-week tea trial reported no differences in liver or kidney markers from placebo. [2] Proper evidence not found for longer use or for plain leaf tea. See liver and kidney cautions.
- Surgery, iron, metals, pesticides. Proper evidence not found in the sources we read. Not described is not proof of none. See herbal tea before surgery.
- Quality. The compound DNJ, which is behind many products' claims, has not been approved as a food supplement according to a 2025 review. [7] NIH notes that the maker, not the FDA, is responsible for supplement safety and labeling. [1]
Tea, capsule or extract?
Powders, capsules and extracts deliver measured amounts of DNJ and other compounds; a cup of tea does not, and trials of one form do not carry over to another. NIH notes safety and results differ by product. [1] See tea vs tincture vs capsule and the mulberry leaf guide.Buying and storing
- Look for the Latin name (Morus alba) and "leaf" on the label; see reading an herbal tea label. Check whether the tea is plain leaf or a blend, because the human trials above tested a blend.
- Strength varies between brands and wild versus commercial leaf. [8]
- See storing herbal tea.
Related pages
What research found and what to check: Mulberry Leaf Tea
Findings about drinking the tea itself, kept apart from capsules, extracts and concentrated supplements. Each card says what was studied, in whom, and how strong the evidence is.
Mulberry leaf tea and blood sugar after meals (blend with water chestnut)
Preliminary or mixedSmall double-blind crossover trials of a mulberry leaf and water chestnut tea found lower blood glucose and insulin after rice in 30 adults with borderline diabetes (3 g of tea), and a lower glucose rise after breakfast and lunch in 20 healthy adults. The tea was a blend, not plain mulberry leaf.
Supplements: Tea (blend): small trials.
Blood sugar swings over two weeks (blend tea)
Preliminary or mixedIn 31 people (double-blind crossover, 2 weeks), a mulberry leaf and water chestnut tea before meals lowered the variation in glucose compared with placebo and lowered 1-hour glucose; there were no differences in low blood sugar events, liver, kidney or inflammation markers.
Supplements: Tea (blend): one small trial.
Mulberry extract and long-term blood sugar (extract only)
Preliminary or mixedA 2025 meta-analysis of 15 trials (1,202 adults with metabolic disorders) of mulberry extract reported improvements in fasting glucose and HbA1c, with different effects by plant part and greater benefit at shorter treatment and lower doses. NIH says clinical research is limited and some trials found no effect.
Supplements: Extract only.
Blood sugar and blood fats in rats (tea)
Lab or animal research onlyIn rats with induced diabetes, white mulberry leaf tea for four weeks did not significantly improve blood glucose, but cholesterol, LDL and triglycerides were lower at the high dose.
Supplements: Lab or animal only.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (1)
- Blood Sugar BalancePreliminary or mixed
Small crossover trials of a mulberry leaf and water chestnut tea lowered blood glucose after meals; NIH says research is limited and mixed.
Body systems (1)
- Blood Sugar SupportPreliminary or mixed
Same small tea-blend trials of post-meal glucose.
Functional actions (1)
- Blood Sugar RegulationPreliminary or mixed
Lower post-meal glucose and glucose variation in small tea-blend trials.
Root causes (1)
- Medication Side EffectsDocumented risk
NIH says mulberry leaf may cause low blood sugar with diabetes medicines.
Biomarkers (1)
- Blood GlucosePreliminary or mixed
Blood glucose after rice was lower with the tea blend at 30 and 60 minutes in 30 adults with borderline diabetes.
Conditions & symptoms (2)
- HypoglycemiaDocumented risk
NIH says low blood sugar may occur when mulberry leaf is taken with diabetes medicines.
- Prediabetes SyndromePreliminary or mixed
30 adults with borderline diabetes had lower glucose and insulin after rice with a mulberry leaf and water chestnut tea; one meal.
Documented risks and interactions (4)
- Blood sugar medicines and low blood sugar. NIH says white mulberry may cause low blood sugar when taken with diabetes medicines. A two-week tea trial found no difference in low blood sugar events versus placebo, but it was small and did not focus on people using medicine.
- Pregnancy and breastfeeding. NIH says safety during pregnancy or breastfeeding is not well established. NHS advises limiting herbal teas in pregnancy because research is limited.
- Mulberry allergy. A 2025 review lists mulberry allergy including respiratory allergy, hives on contact, oral allergy syndrome, anaphylaxis and food-triggered hives.
- Digestive side effects, liver and kidney markers. NIH says studies up to 12 weeks reported no serious harm, and the most common effect is digestive upset such as bloating, constipation, gas and loose stools. The two-week tea trial reported no differences in liver or kidney markers from placebo.
Frequently asked questions
Does mulberry leaf tea lower blood sugar?
Small trials of a mulberry leaf and water chestnut tea found lower blood sugar after meals compared with placebo, but they were short and used a blend. [3][2] NIH says research is limited and some trials found no effect. [1]
Is mulberry leaf tea safe with diabetes medicine?
NIH says it may cause low blood sugar with diabetes medicines. [1] Ask a prescriber or pharmacist first.
Is mulberry leaf tea safe in pregnancy?
NIH says safety is not well established. [1] Ask your clinician.
Does mulberry leaf tea have caffeine?
A general review says herbal teas do not contain caffeine, but it was not measured for mulberry leaf tea in any source we read. [9]
Do extract results apply to the tea?
No. A 2025 analysis of extract trials found benefit for HbA1c, but extracts differ from a cup of tea. [6]
References
- National Center for Complementary and Integrative Health (NIH). White Mulberry Leaf. Page updated September 2023. Read 2026-10-24.
- Shinkawa Y, Yasuda M, et al. Evaluation of the Postprandial-Hyperglycemia-Suppressing Effects and Safety of Short-Term Intake of Mulberry Leaf and Water Chestnut Tea: A Randomized Double-Blind Placebo-Controlled Crossover Trial. Nutrients. 2025. PubMed 40732933. Abstract read 2026-10-24.
- Yasuda M, Yasutake K, et al. Mulberry leaves and water chestnut tea reduces postprandial blood glucose in borderline diabetic Japanese: a randomized, double-blind, placebo-controlled crossover study. Asia Pac J Clin Nutr. 2025. PubMed 40134056. Abstract read 2026-10-24.
- Yasutake K, Agune M, Yasuda M. Effects of mulberry leaves and water chestnut husk tea on postprandial and second meal interstitial glucose in healthy adults. Asia Pac J Clin Nutr. 2026. PubMed 42242851. Abstract read 2026-10-24.
- Wilson RD, Islam MS. Effects of white mulberry (Morus alba) leaf tea investigated in a type 2 diabetes model of rats. Acta Pol Pharm. 2015. PubMed 25850211. Animal study. Abstract read 2026-10-24.
- Yu JT, Li CP, Hsiao Y, Cheng KP, Tsai RY. Integrative evidence on mulberry extract for modulating metabolic risk factors associated with vascular dementia. Int J Mol Sci. 2025;26(17):8380. PubMed 40943306. Abstract read 2026-10-24.
- Tricase AF, Cavalluzzi MM, Catalano A, et al. Insights into the activities and usefulness of deoxynojirimycin and Morus alba: a comprehensive review. Molecules. 2025;30(15):3213. PubMed 40807388. Abstract read 2026-10-24.
- Janiak MA, Gryn-Rynko A, Sulewska K, et al. Phenolic profiles and antioxidant activity of Morus alba L. infusions prepared from commercially available and naturally collected leaves. Sci Rep. 2025;15:13030. PubMed 40234700. Abstract read 2026-10-24.
- Huda HS, Majid NBA, Chen Y, et al. Exploring the ancient roots and modern global brews of tea and herbal beverages: a comprehensive review. Food Sci Nutr. 2024. First 100,000 characters read 2026-10-24.
- NHS. Foods to avoid in pregnancy. Page reviewed 15 June 2026. Read 2026-10-24.