NutriStack
Metformin and Psyllium Husk, timing-sensitive.
Psyllium forms a viscous gel that slows gastric emptying and can bind oral drugs in the gut, modestly reducing their absorption. Metformin is a relatively low-bioavailability drug (50-60%) that depends on enterocyte transporters in the small intestine. Co-administering psyllium with metformin can lower metformin Cmax and possibly its glucose-lowering effect, although clinical impact varies.
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.
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At a glance
- Substances
- Metformin and Psyllium Husk
- Pair type
- Timing Sensitive
- Evidence (highest tier)
- Emerging
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored timing-sensitive row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Timing Sensitive · Emerging evidence
Timing Sensitive
What is happening. Psyllium forms a viscous gel that slows gastric emptying and can bind oral drugs in the gut, modestly reducing their absorption. Metformin is a relatively low-bioavailability drug (50-60%) that depends on enterocyte transporters in the small intestine. Co-administering psyllium with metformin can lower metformin Cmax and possibly its glucose-lowering effect, although clinical impact varies.
Mechanism. Psyllium's soluble fiber forms a hydrogel that physically traps small molecules, slows gastric emptying, and can reduce the rate (and sometimes extent) of drug absorption. Metformin is absorbed via PMAT/OCT3 transporters in the upper small intestine, where its absorption is sensitive to transit time and viscosity.
Recommendation. Take psyllium and metformin at different times, ideally with metformin taken 2 hours before or 4 hours after psyllium. Drink plenty of water with both.
Minimum separation. 120
Stack Score
How this pair moves the number.
Effect on the composite score
If both Metformin and Psyllium Husk are in the same stack, this pair applies −5 to your Stack Score (per scored timing-sensitive row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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