Distil ← Back to home
Class landing · Metformin

Supplements and metformin.

Glucose-lowering supplements, B12 depletion, and the additive-effect pairs to watch.

Metformin is the first-line oral diabetes drug and the most-cited example of medication-induced nutrient depletion. After a year or more of daily use, vitamin B12 levels fall in roughly 10 to 30 per cent of patients. Annual B12 monitoring is sensible; supplementation is straightforward if needed.

Several supplements have their own glucose-lowering effect and stack additively with metformin: berberine, alpha-lipoic acid, inositol, chromium, and bitter melon all have evidence here. Adding any of these without monitoring fasting glucose carries hypoglycaemia risk. None of them are excluded; they are pairs where home glucose monitoring at the start makes sense.

Related guides

Loading database stats…
For adults over 18. This tool gives evidence-graded information, not medical advice. Always discuss changes with your GP, especially if you take any medication, are pregnant, breastfeeding, or have a serious health condition.
Type the supplement name. Click each match to add it.
Brand or generic name works. Click each match to add it.
Anything we should know? (optional)
Pick any that apply. We adjust the findings where context changes the answer.
Add at least one supplement and one medication to check.
Not sure where to start? Try one:
How we decide

How we grade severity, choose what's in scope, and what we exclude.

Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.

Read the full methodology
Your whole stack

Want this checked across everything you take?

This page checks the pairs you enter. The personalised Distil report goes further:

  • the same graded, cited interaction check across your whole stack, not just the pairs you thought to type in
  • where your current routine may be leaving you short of your goals
  • the evidence-backed compounds worth adding, and the ones worth dropping

It's a paid report: £79, or £49 for the first 25 customers. The interactions check is one section of it, and you can read a real one in full before you buy.

See a real sample report
Distil's interactions database is reviewed and updated every quarter. We grade evidence transparently and publish our methodology, including every database change, at /about/methodology. This tool is information, not a substitute for clinical judgement. If you take medication and supplements together, your GP or pharmacist can review your full regimen against your medical history. If you want a full personalised stack reasoned against this same database, the Distil report is the next step up.