Supplement · Grade A

TMG and medications.

Not yet catalogued in the Distil interactions database. We surface that distinction explicitly.

TMG is in the Distil supplement database, evidence Grade A. The page below lists every medication we have explicitly assessed it against.

TMG, also called trimethylglycine or betaine, is a methyl donor whose best-established use is lowering homocysteine, a marker tied to cardiovascular and dementia risk. The evidence for homocysteine reduction is Grade A, supported by Olthof's work, with a weaker Grade B case for strength and power output from resistance training, anchored by Cholewa. The usual dose is 1.25 to 2.5g daily. Its main relevance to other supplements is cooperative rather than cautionary: TMG works within the methylation cycle alongside methylcobalamin B12 and methylfolate, which makes it a sensible pairing for people with an MTHFR variant who are already taking methylfolate. There are no major drug interactions noted. At higher doses it can cause loose stools or stomach upset, and a small subset of people with an FMO3 variant notice a fishy body odour. It is a clean, well-studied option where the goal is methylation support or bringing homocysteine down.

We have not yet completed an explicit assessment of medications for TMG in the Distil interactions database. We surface this distinction deliberately: the Distil checker tells you when we have explicitly assessed a pair and when we have not, because both are useful information. If you take TMG alongside a medication, the checker below will surface anything already in our database, and the missing-item form at the bottom of the page routes uncatalogued pairs into our next curation pass.

What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.

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.

Your supplements

Type the supplement name. Click each match to add it.

Your medications

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.

I confirm I am 18 or over. This tool gives evidence-graded information, not medical advice; always discuss changes with your GP or pharmacist.

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

Something missing?

If a supplement or medication you take isn't in our autocomplete, tell us. We go through what people flag every week and add what's missing.

Thanks, that's logged. We go through flagged items every week.

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.