Buckwheat Tea: What Research Shows About the Tea, Safety and Cautions
What we found about roasted buckwheat tea (soba-cha): buckwheat allergy can be severe, the grain is gluten-free by nature but can be cross-contaminated, and no human trials of the tea exist.
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: buckwheat can cause true allergic reactions, including severe ones, in some people [1][2], and the grain is gluten-free by nature but can pick up gluten from other grains during handling [3][4]. Buckwheat tea is a roasted-seed drink, not a tea-plant tea. This page is about the drink itself. It keeps it separate from buckwheat as a food and from rutin supplements.
What buckwheat tea is
Buckwheat tea is an infusion of roasted buckwheat seeds (sometimes the bran). Despite the name, buckwheat is not a wheat or a grass: common buckwheat, Fagopyrum esculentum Moench, belongs to the knotweed family, Polygonaceae. [5] A second species, Tartary buckwheat (Fagopyrum tataricum), is also made into tea, and much of the research on tea is on Tartary buckwheat. [6][7] A label that only says "buckwheat" may not tell you which. It has no tea-plant leaf, so it is a herbal tea (tisane); see Tisane vs Tea. The older, broader grain discussion is in Whole Grains and Ancient Grains.Taste, caffeine and how to brew
| Question | What sources say |
|---|---|
| Taste | Proper evidence not found in the sources we read for a taste description. |
| Caffeine per 8 fl oz (240 mL) cup | Proper evidence not found. None of the sources we read measured or stated caffeine for buckwheat tea. See caffeine in herbal teas. |
| Water temperature and steeping time | There is no official instruction. In one study of roasted Tartary buckwheat, 6 g of bran or grain was rinsed with 300 mL of hot water above 203 °F (95 °C) for 30 seconds. [6] A laboratory study compared roasted Tartary buckwheat brewed 3 minutes at 185 to 194 °F (85 to 90 °C) with 24 hours at room temperature, and found more polyphenols and flavonoids in the long room-temperature brew, measured in the lab only. [7] This is research information, not advice. |
| Amount of seed per cup | Proper evidence not found for an official figure. |
| Rutin in the cup | In that first infusion, the Tartary bran tea contained about 389 mg of rutin per liter and the grain tea about 68 mg per liter. [6] Rutin is a plant flavonoid. |
| Cold brew / iced | One lab study used a 24-hour room-temperature brew. [7] Long room-temperature brewing raises food-safety questions; see cold brew and iced herbal tea safety. |
What research found about the tea itself
Labels used: Insufficient evidence, Lab or animal only, Extract only.| Question | What the source found | Strength of evidence | Form and who was studied |
|---|---|---|---|
| Any health outcome from drinking the tea | Proper evidence not found for a human trial of buckwheat tea. Our Europe PMC searches of titles and abstracts for "buckwheat tea" returned papers on flavor, roasting and rutin measurement, not trials in people. [8] | Insufficient evidence | Tea |
| Antioxidant activity of the brew | Roasted Tartary buckwheat tea brewed at room temperature for 24 hours showed the highest antioxidant activity in test-tube assays and slowed growth of human pancreatic and breast cancer cells in a dish; rutin was the main contributor. [7] | Lab or animal only | Cells and chemical tests; not a result in people |
| Blood sugar, cholesterol, insulin in type 2 diabetes | In an open-label trial of 165 people for 4 weeks, replacing part of the staple food with Tartary buckwheat food lowered fasting insulin, total cholesterol and LDL cholesterol compared with a diet-only group; blood glucose and HbA1c did not differ. [9] | Promising but limited (open-label, short; food, not tea) | Tartary buckwheat as a food, not a tea |
| Kidney markers in type 2 diabetes | In a 4-week open-label trial of 104 people, the Tartary buckwheat food group had lower urine albumin-to-creatinine ratio and urea nitrogen than the diet-only group. [10] | Promising but limited (open-label, short; food, not tea) | Tartary buckwheat as a food, not a tea |
| Leg symptoms in chronic venous insufficiency | A systematic review of 15 trials found hydroxyethylrutosides, a semisynthetic rutin derivative sold as a standardized product, modestly improved pain, heavy legs and cramps; the trials were of limited quality. [11] | Extract only (a modified compound, not tea) | Standardized products, 1,643 people in total |
The rutin trials are of standardized products or foods, not a cup of tea. A tea cup holds much less than a rutin product, and we do not convert one into the other.
Check before you drink
- Buckwheat allergy. A 2021 review says buckwheat can cause IgE-mediated allergy, including severe reactions and anaphylaxis. It estimates 0.1 to 0.4% of people in Japan, Korea and buckwheat-eating areas of China are affected, and that severe reactions are rare overall. [1] It also describes cross-reactivity between buckwheat and peanut, latex, coconut, quinoa and poppy seed. [1] A 2024 review says most research is from Japan and Korea. [2] We found no source on allergy to the tea specifically. Severe allergic reactions are an emergency; in the US, call 911. See herbal tea allergy and cross-reactions.
- Gluten. Buckwheat is inherently gluten-free, but a 2020 study showed it can pick up gluten when it touches broken wheat, rye, barley or oat grains or contaminated surfaces. [3] A 2025 Turkish market study found gluten in a share of flours, and more often in buckwheat and oat flours than in corn and rice flours; some labeled gluten-free flours also tested above 20 mg/kg. [4] Those were flours, not tea, and nobody we read measured gluten in buckwheat tea. NHS lists wheat, barley and rye as the gluten cereals and does not list buckwheat. [12] Under FDA's rule a "gluten-free" claim needs under 20 parts per million. [13] If you have coeliac (celiac) disease, look for a gluten-free label and ask your clinician or dietitian.
- Skin sensitivity to light. A 2026 paper says buckwheat contains fagopyrin F, a photosensitizer, and that household heating reduced it in grain. [14] We found no source linking buckwheat tea to skin reactions, so we make no claim either way.
- Pregnancy, breastfeeding, babies and children. Proper evidence not found in the sources we read. Herbal drinks are not recommended for infants; see herbal tea for babies and children.
- Medicines, liver, kidney, iron. Proper evidence not found in the sources we read for buckwheat tea. Not described is not proof of none. Ask a pharmacist about your medicines (how interactions work).
- Lead, other metals, pesticides, mold. Proper evidence not found for buckwheat tea. See organic and pesticide residues.
- Very hot drinks. No source we read ties this to buckwheat tea, but IARC says very hot drinks above about 149 °F (65 °C) are probably carcinogenic to the esophagus. See hot tea and esophageal cancer risk.
Tea, capsule or extract?
A cup of roasted buckwheat tea is not a rutin or quercetin supplement and not a bowl of buckwheat. The food trials above replaced part of the staple food, and the venous trials used a modified rutin product. Do not carry those results over to a cup. See tea vs tincture vs capsule.Buying and storing
- Check the label for the species (common or Tartary) and whether it is pure roasted buckwheat or a blend. See reading an herbal tea label.
- If you avoid gluten, choose a product with a gluten-free label. In the studies above, naturally gluten-free buckwheat products without that kind of control were more often contaminated. [3][4]
- Storage and keeping time: storing herbal tea.
Related pages
What research found and what to check: Buckwheat 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.
Rutin in the brew
Not enough evidenceRutin is a plant flavonoid. In roasted Tartary buckwheat tea, the first infusion contained about 389 mg per liter from bran and about 68 mg per liter from grain (6 g in 300 mL of hot water, 30 seconds).
Supplements: Rutin trials in people used standardized products, not tea.
Antioxidant activity of the brew (laboratory)
Lab or animal research onlyRoasted Tartary buckwheat tea brewed at room temperature for 24 hours had the highest antioxidant activity in test-tube assays and slowed growth of human pancreatic and breast cancer cells in a dish; rutin contributed most.
Supplements: Lab only.
Blood sugar, cholesterol and insulin in type 2 diabetes (buckwheat food)
Preliminary or mixedIn a 4-week open-label trial of 165 people, replacing part of the staple food with Tartary buckwheat food lowered fasting insulin, total cholesterol and LDL cholesterol compared with a diet-only group; blood glucose and HbA1c did not differ.
Supplements: Not shown for the tea.
Kidney markers in type 2 diabetes (buckwheat food)
Preliminary or mixedIn a 4-week open-label trial of 104 people, Tartary buckwheat food lowered urine albumin-to-creatinine ratio and urea nitrogen compared with diet alone.
Supplements: Not shown for the tea.
Rutin products and leg symptoms (extract only)
Preliminary or mixedA systematic review of 15 trials found hydroxyethylrutosides, semisynthetic rutin derivatives sold as standardized products, modestly improved pain, heavy legs and cramps in chronic venous insufficiency; the trials were of limited quality.
Supplements: Extract only.
Fagopyrin F and light sensitivity
Not enough evidenceA 2026 paper says buckwheat contains fagopyrin F, a photosensitizer, and that household heating (including pan roasting) reduced it in grain. We found no source linking buckwheat tea to skin reactions.
Supplements: No tea measurement or case found.
Caffeine, pregnancy, children, medicines
Not enough evidenceProper evidence not found in the sources we read for caffeine, pregnancy, breastfeeding, babies and children, or medicines. Not described is not proof of none.
Supplements: Ask a clinician.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Conditions & symptoms (2)
- Food AllergyDocumented risk
Buckwheat can cause IgE-mediated food allergy, including anaphylaxis, with cross-reactions to peanut, latex, coconut, quinoa and poppy seed. Severe reactions are rare overall. No source on allergy to the tea specifically was found.
- Celiac DiseaseDocumented risk
Buckwheat is gluten-free by nature, but cross-contact with gluten grains can contaminate it; nobody we read measured gluten in buckwheat tea.
Documented risks and interactions (2)
- Buckwheat allergy. A 2021 review says buckwheat can cause IgE-mediated allergy, including severe reactions and anaphylaxis, and estimates about 0.1 to 0.4% of people are affected in Japan, Korea and buckwheat-eating areas of China; severe reactions are rare overall. Cross-reactions are described with peanut, latex, coconut, quinoa and poppy seed. No source on allergy to the tea specifically was found.
- Gluten: gluten-free by nature, but cross-contact happens. Buckwheat is inherently gluten-free, but a 2020 study showed it can pick up gluten from broken wheat, rye, barley or oat grains or contaminated surfaces. A 2025 market study found gluten more often in naturally gluten-free flours without gluten-free labels, with buckwheat and oat flours more contaminated than corn and rice. These were grain and flour studies, not tea.
Frequently asked questions
Is buckwheat tea gluten-free?
Buckwheat is inherently gluten-free, but it can be contaminated with gluten grains during handling. [3][4] We found no measurement of gluten in the tea itself. Look for a gluten-free label if you have coeliac disease.
Can buckwheat tea cause an allergic reaction?
Buckwheat is a recognized cause of food allergy, sometimes severe. [1] We found no source on the tea specifically. If you are allergic to buckwheat, peanut, latex, coconut, quinoa or poppy seed, ask an allergy clinician first. [1]
Does buckwheat tea have caffeine?
Proper evidence not found. None of the sources we read stated caffeine for buckwheat tea.
Does buckwheat tea work for blood sugar or blood pressure?
Proper evidence not found for trials of the tea. The diabetes trials we read used Tartary buckwheat food, lasted 4 weeks and were open-label. [9][10]
Is buckwheat tea a source of rutin?
A study of roasted Tartary buckwheat found rutin in the brew, more from the bran than from the grain. [6] Rutin trials in people have used standardized products, not tea. [11]
References
- Norback D, Wieslander G. A review on epidemiological and clinical studies on buckwheat allergy. Plants (Basel) 2021. PubMed 33806876. Read 2026-10-23 (abstract).
- Kajita N, Yoshida K. Buckwheat allergy in Asia. Curr Allergy Asthma Rep 2024. PubMed 38976201. Read 2026-10-23 (abstract).
- Atasoy G, Ulutas B, Turhan M. Potential ways for gluten contamination of gluten-free grain and gluten-free foods: the buckwheat case. Food Addit Contam Part A 2020. PubMed 32805193. Read 2026-10-23 (abstract).
- Ocal HY, Ozel HG. Naturally gluten-free flours are commonly contaminated, while commercially produced gluten-free flours are relatively safe: a market-based study in Turkey. Front Nutr 2025. PubMed 41459067. Read 2026-10-23 (abstract).
- GBIF Secretariat. GBIF Backbone Taxonomy species match, Fagopyrum esculentum Moench (Polygonaceae), accepted name, checked through api.gbif.org on 2026-10-23. Read 2026-10-23.
- Noda T, Ishiguro K, Suzuki T, Morishita T. Roasted Tartary buckwheat bran as a material for producing rutin-rich tea beverages. Plants (Basel) 2021. PubMed 34961131. Read 2026-10-23 (abstract).
- Ryu JY, Choi Y, Hong KH, Chung YS, Cho SK. Effect of roasting and brewing on the antioxidant and antiproliferative activities of Tartary buckwheat. Foods 2020. PubMed 32967348. Laboratory study. Read 2026-10-23 (abstract).
- European Bioinformatics Institute. Europe PMC search, title/abstract searches run 2026-10-23: "buckwheat tea" (flavor, roasting and rutin-measurement papers; no human trial), "buckwheat tea" with caffeine (0 records). Read 2026-10-23.
- Qiu J, Liu Y, Yue Y, Qin Y, Li Z. Dietary tartary buckwheat intake attenuates insulin resistance and improves lipid profiles in patients with type 2 diabetes: a randomized controlled trial. Nutr Res 2016. PubMed 27919453. Read 2026-10-23 (abstract).
- Qiu J, Li Z, Qin Y, Yue Y, Liu Y. Protective effect of tartary buckwheat on renal function in type 2 diabetics: a randomized controlled trial. Ther Clin Risk Manag 2016. PubMed 27920542. Read 2026-10-23 (abstract).
- Aziz Z, Tang WL, Chong NJ, Tho LY. A systematic review of the efficacy and tolerability of hydroxyethylrutosides for improvement of the signs and symptoms of chronic venous insufficiency. J Clin Pharm Ther 2015. PubMed 25630350. Read 2026-10-23 (abstract).
- NHS (UK). Coeliac disease: overview. Read 2026-10-23.
- U.S. Food and Drug Administration. Gluten and Food Labeling. Content current as of 07/16/2018. Read 2026-10-23.
- Kim J, Lee SA, Kim J. Effects of household processing on rutin and fagopyrin F in common and Tartary buckwheat. Foods 2026. PubMed 42794069. Read 2026-10-23 (abstract).