Short answer

We found no documented interaction between Fenugreek and B-complex in the sources below. That isn't proof the combination is right for you: check each one's cautions, and ask your pharmacist if you take medication.

Fenugreek

What it is: A clover-like herb whose seeds are used as a spice and traditional medicine.

What the research says: It may help lower blood sugar in type 2 diabetes, but many studies were low quality. Evidence for other uses is too limited.

Cautions

• It can cause diarrhea, nausea and other stomach symptoms; large doses may drop blood sugar too far.
• It can cause allergic reactions, sometimes serious.
• Not safe in pregnancy in amounts above those in food.

Medicines to check

• Diabetes medicines: large doses may lower blood sugar further

In Holitro: Fenugreek (500 mg per capsule)

Source: NIH National Center for Complementary and Integrative Health: Fenugreek: Usefulness and Safety (updated February 2025)

B-complex (active forms)

What it is: A mix of B vitamins in their active forms.

What the research says: B vitamins help turn food into energy and keep blood and nerve cells healthy; a supplement helps if your diet falls short.

Cautions

• High-dose folate can hide a vitamin B12 deficiency.
• Taking a lot of vitamin B6 for a year or more can cause nerve damage.
• Niacin at 30 mg or more can cause flushing and itching.

Medicines to check

• Methotrexate: folate can interfere with it
• Anti-seizure medicines (folate and vitamin B6 notes)

In Holitro: Methyl B-Complex

Sources: NIH Office of Dietary Supplements: Folate: Fact Sheet for Consumers (updated November 2022); NIH Office of Dietary Supplements: Vitamin B6: Fact Sheet for Consumers (updated June 2023); NIH Office of Dietary Supplements: Niacin: Fact Sheet for Consumers (updated March 2021)

Check with your doctor or pharmacist, especially if you take medication.

Check your stack — free

Educational information only, not medical advice. This reflects general ingredient overlap, not a personalized safety review. Always check with your doctor or pharmacist before combining supplements, especially if you take medication, are pregnant or nursing, or manage a health condition. These statements have not been evaluated by the FDA.