Evidence explainerFenugreek

Fenugreek Side Effects: Digestive Upset, Low Blood Sugar and a Pregnancy Warning

Food amounts are considered safe. Larger amounts can upset digestion and drop blood sugar, NCCIH says fenugreek is not safe in pregnancy above food amounts, and allergies can be serious.

By Kymata Health editorial teamPublished October 9, 2026Last reviewed October 9, 2026

Medical review pending. Written by our editorial team from the studies cited below; a credentialed clinician has not reviewed it yet. Educational only, not medical advice.

Key takeaways

  • NCCIH lists diarrhea, nausea and other digestive symptoms as possible side effects [1].
  • Large doses may cause a harmful drop in blood sugar [1].
  • Fenugreek can cause allergic reactions, including serious ones [1].
  • NCCIH says it is not safe during pregnancy in amounts greater than those found in food; use has been linked to increased risks of birth defects in animals and people [1].
  • Little is known about the safety of amounts above food levels while breastfeeding [1].

The evidence, graded

Pulled from our monograph evidence tables. Grades follow our evidence-grading policy.

  • Grade CWorsenedFasting and 2-hour blood sugar and HbA1cFenugreek · Meta-analysis · n=706 · 2023 · PMID 37762302Fasting blood sugar, 2-hour glucose and HbA1c fell versus control; insulin resistance (HOMA-IR) did not change significantly. No liver or kidney toxicity or severe adverse events; mild digestive side effects in some studies.

Common side effects

NCCIH considers fenugreek safe for adults and children in the amounts commonly found in foods, and possibly safe for adults in larger amounts [1]. There is not enough information to say whether larger amounts are safe for children [1].

Possible side effects include diarrhea, nausea and other digestive symptoms, and large doses may cause a harmful drop in blood sugar [1]. In a 2023 meta-analysis of 10 trials, no liver or kidney toxicity or severe adverse events were seen, though some studies reported mild digestive side effects [2].

Pregnancy and breastfeeding

NCCIH says fenugreek is not safe during pregnancy in amounts greater than those found in food, because its use has been linked to increased risks of birth defects in both animals and people [1]. A 2016 toxicology review collected reports of malformations in humans and animals and concluded fenugreek is not recommended during pregnancy [3].

For breastfeeding, NCCIH says little is known about the safety of amounts above food levels, and that studies of milk supply have had mixed results [1]. A 2018 network meta-analysis found more breast milk with fenugreek than placebo in 4 small studies (122 participants took fenugreek across 5 studies) [4].

Allergies and medicines

Fenugreek can cause allergic reactions, including serious ones [1]. The toxicology review advises avoiding it with a peanut or chickpea allergy because of possible cross-reactivity, and with chronic asthma [3].

NCCIH advises anyone taking any medicine to talk with a health care provider before using fenugreek [1]. Its blood-sugar warning matters most for people on blood-sugar-lowering medicines.

In one case report, a patient on warfarin who was taking boldo and fenugreek products had a raised INR that returned to normal about 1 week after stopping them, and rose again when both were restarted [5]. The two herbs were taken together, so fenugreek alone cannot be singled out [5].

For the blood-sugar evidence, read fenugreek and blood sugar.

Quick answers

Does fenugreek make you smell like maple syrup?

NCCIH notes that the seeds smell and taste like maple syrup [1]. Our sources do not report on body odor.

Can fenugreek affect the liver or kidneys?

In a 2023 meta-analysis of 10 trials, no liver or kidney toxicity was observed [2].

Is fenugreek safe for children?

NCCIH considers food amounts safe for children, but says there is not enough information on larger amounts [1].

Keep reading

Full monographs

Related articles

Browse the full Supplement & Nutrient Encyclopedia or all supplement articles.

References

  1. [1]Fenugreek (Last Updated: February 2025). National Center for Complementary and Integrative Health (NCCIH), 2025.
  2. [2]The Effect of Fenugreek in Type 2 Diabetes and Prediabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Int J Mol Sci, 2023. PMID 37762302
  3. [3]Toxicological properties of fenugreek (Trigonella foenum graecum). Food Chem Toxicol, 2016. PMID 27498339
  4. [4]Effectiveness of fenugreek as a galactagogue: A network meta-analysis. Phytother Res, 2018. PMID 29193352
  5. [5]Potential interaction between warfarin and boldo-fenugreek. Pharmacotherapy, 2001. PMID 11310527

Fenugreek and other dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Talk to your clinician or pharmacist before starting a supplement, especially if you take prescription medicines. This page has no product or affiliate links.