Adjunct therapies
What happens when a supplement or a behavior is added to a prescription drug? Choose a therapy to see every graded pairing for it — including the ones where the evidence shows no added benefit, or points to harm.
First pairings are in review
Each pairing is checked against its sources before it is published here. The first set covers widely prescribed therapies such as statins, metformin, GLP-1 medicines and methotrexate.
How to read a pairing
Every pairing carries one of five evidence states. They describe what the combination evidence shows — not how good either part is on its own, which is what each intervention’s own grade measures.
- Additive · documented
- Trials show the combination does better than the drug alone.
- Synergistic · documented
- Trials show more benefit together than the two would give separately.
- No benefit shown · documented
- It was tested properly and added nothing. A firm “no” is as useful as a “yes”: it saves money, pills and false hope.
- Antagonistic · documented
- The pairing works against the drug, or causes harm — for example by blocking its absorption.
- Plausible · not yet tested
- There is a sound reason to expect an effect, but nobody has tested the combination yet.
Four kinds of pairing
- Depletion — the drug lowers a nutrient (metformin and vitamin B12).
- Countermeasure — the add-on offsets a side effect (folate with methotrexate).
- Augmentation — the add-on is tested for extra benefit (exercise with GLP-1 therapy).
- Conflict — the add-on interferes with the drug (calcium or iron with levothyroxine).
This page describes published evidence. It is not advice to add, stop or change anything in a prescribed treatment — talk to the prescriber or a pharmacist first. Pairings marked “In queue for final human review” were drafted with AI assistance from published sources and proofed, and are awaiting final review by a ClinEvident rater.
Looking for two supplements, or a supplement and a behavior, together? Use the interaction checker.