What kind of interaction is it?

Caution: an interaction that may reduce efficacy or raise side-effect risk and warrants monitoring.

Is this interaction backed by published research?

Yes. NutriStack lists 2 citation rows for the Fenugreek + Metformin pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Interaction databaseSupplement × PrescriptionReviewed May 2026

Fenugreek and Metformin, a caution.

Q: Can I take Fenugreek and Metformin together?

Possibly, but with caution. Fenugreek and Metformin have a documented caution-tier interaction. Fenugreek seed extracts (typically standardized to ~50% galactomannan fiber and 4-hydroxyisoleucine) lower fasting glucose and HbA1c in randomized trials of type 2 diabetes. Combined with metformin, the additive glucose-lowering is usually beneficial but can produce hypoglycemia in patients who already have HbA1c near target, are eating less, or also take insulin or a sulfonylurea.

Q: How does this affect a NutriStack Stack Score?

-5 to your Stack Score per scored caution row.

Fenugreek seed extracts (typically standardized to ~50% galactomannan fiber and 4-hydroxyisoleucine) lower fasting glucose and HbA1c in randomized trials of type 2 diabetes. Combined with metformin, the additive glucose-lowering is usually beneficial but can produce hypoglycemia in patients who already have HbA1c near target, are eating less, or also take insulin or a sulfonylurea.

2 primary source citations. Moderate evidence. Last verified May 30, 2026.

Open the interaction checker →Read the methodology

One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.

Sourcing standards·Evidence tiers

From the interaction database

What the row says.

Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.

At a glance

Substances: Fenugreek and Metformin
Pair type: Caution
Evidence (highest tier): Moderate
Source citations: 2 sources
Stack Score effect: −5 to your Stack Score (per scored caution row).
Scope: Supplement × Prescription
Last verified: May 30, 2026

Caution · Moderate evidence

Caution

What is happening. Fenugreek seed extracts (typically standardized to ~50% galactomannan fiber and 4-hydroxyisoleucine) lower fasting glucose and HbA1c in randomized trials of type 2 diabetes. Combined with metformin, the additive glucose-lowering is usually beneficial but can produce hypoglycemia in patients who already have HbA1c near target, are eating less, or also take insulin or a sulfonylurea.

Mechanism. Fenugreek's 4-hydroxyisoleucine stimulates glucose-dependent insulin secretion, and its soluble fiber slows carbohydrate absorption and may reduce hepatic glucose output. Metformin reduces hepatic gluconeogenesis (via AMPK activation and mitochondrial complex I inhibition) and improves peripheral insulin sensitivity. Effects are additive on fasting and postprandial glucose.

Recommendation. Tell your prescriber before starting a fenugreek extract on metformin. Monitor fasting and pre-meal glucose for the first 2-4 weeks. Consider taking the two with a 1-2 hour gap, since fenugreek's soluble fiber can slow drug absorption.

Minimum separation. 120

Sources (2)

Stack Score

How this pair moves the number.

Effect on the composite score

If both Fenugreek and Metformin are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).

The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.

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