NutriStack
Fenugreek and Garlic Extract, a caution.
Fenugreek has documented, though mostly preclinical, antiplatelet effects, and garlic extract is a well-established platelet aggregation inhibitor in humans. Used together, especially at higher doses, they may additively prolong bleeding tendency. This is usually subclinical in healthy people but becomes relevant for those on anticoagulant or antiplatelet medication (warfarin, aspirin, clopidogrel) or approaching surgery.
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.
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 Garlic Extract
- Pair type
- Caution
- Evidence (highest tier)
- Emerging
- Source citations
- 3 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Caution · Emerging evidence
Caution
What is happening. Fenugreek has documented, though mostly preclinical, antiplatelet effects, and garlic extract is a well-established platelet aggregation inhibitor in humans. Used together, especially at higher doses, they may additively prolong bleeding tendency. This is usually subclinical in healthy people but becomes relevant for those on anticoagulant or antiplatelet medication (warfarin, aspirin, clopidogrel) or approaching surgery.
Mechanism. Both have antiplatelet activity. Fenugreek contains coumarin constituents and has shown platelet aggregation inhibition in laboratory and animal studies, while garlic's organosulfur compounds (allicin, ajoene) inhibit platelet aggregation through thromboxane and cyclooxygenase pathways. Combined use can additively reduce platelet function.
Recommendation. Healthy individuals taking ordinary supplemental doses generally do not need to avoid this combination. If you take blood thinners, have a bleeding disorder, or have surgery or a dental procedure scheduled, tell your clinician and consider pausing both 1 to 2 weeks beforehand. Watch for easy bruising, nosebleeds, or prolonged bleeding from minor cuts. No timing separation reduces this effect since the risk is systemic and cumulative.
Minimum separation. None; separating doses does not reduce the additive systemic antiplatelet effect
Sources (3)
- Basch E et al. Therapeutic applications of fenugreek. Altern Med Rev. 2003;8(1):20-7. PMID 12611558
- Allison GL et al. Aged garlic extract and its constituents inhibit platelet aggregation through multiple mechanisms. J Nutr. 2006;136(3 Suppl):782S-788S. PMID 16484563
- Rahman K et al. Dietary supplementation with aged garlic extract inhibits ADP-induced platelet aggregation in humans. J Nutr. 2000;130(11):2662-5. PMID 11053504
Stack Score
How this pair moves the number.
Effect on the composite score
If both Fenugreek and Garlic Extract 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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