Best TMG Supplement UK (2026): The 1.5g Claim Threshold, Anhydrous vs HCl, and Single vs Combination
Best TMG supplement UK: the 1.5g rule, and why most 1g products break it.
Trimethylglycine is a simple molecule with one authorised claim, and that claim has a dose condition most UK products do not meet. Here is how to read a TMG label — form, dose, claims, partners — and when a single-ingredient TMG makes more sense than an NMN combination.
TMG (trimethylglycine, betaine anhydrous) is the amino acid glycine carrying three methyl groups — a naturally occurring methyl donor found in beetroot, spinach and wheat bran. It carries one authorised UK/EU health claim, conditional on 1.5g a day; most UK products supply 1g and may not use it.
- Check the form: the label should say betaine anhydrous. "Betaine" alone could be the hydrochloride, a different product.
- Check the claim against the dose: homocysteine or methylation wording on a product under 1.5g a day is unauthorised, and a sign the seller is not reading the register.
- Decide single or combination: NMN + TMG formulas fix the ratio at 750mg each; a single-ingredient TMG in 500mg capsules lets you set it.
The 1.5g rule: one authorised claim, and a dose condition
The GB and EU nutrition and health claims register carries exactly one authorised health claim for betaine. It is not a free pass. It comes with two conditions of use: the product must provide 1.5g of betaine per day, and the label must carry a statement that a daily intake above 4g may significantly increase blood cholesterol. Meet both and the claim is available. Miss either and it is not.
The typical UK TMG capsule product supplies 1g a day — two 500mg capsules. That is below the threshold, so the claim is unavailable to it, and by extension every softer version of the same idea ("methylation support", "supports healthy homocysteine") is an unauthorised health claim on that product. This is the single most common compliance failure in the category, and it is on the front of a great many packs.
| Daily dose on label | Claim available? | What a compliant listing can say |
|---|---|---|
| 1000mg (2 × 500mg) | No — below the 1.5g condition | What it is, the form, the dose, what else is in the capsule. Nothing about what it does. |
| 1500mg or more | Yes — if the 4g cholesterol warning is also printed | The authorised wording, with the mandatory warning alongside it |
| Undeclared ("methylation blend") | Cannot be assessed | Nothing that depends on the betaine dose |
Our own single-ingredient TMG is a 1g product, so it makes no claim — and its product page says so in as many words. We would rather explain the rule than quietly break it.
Anhydrous vs HCl: the word that tells you what you are buying
Trimethylglycine, betaine and betaine anhydrous are the same compound. "Anhydrous" means the crystalline form contains no water of crystallisation — it is the standard supplement form, typically produced from sugar beet (Beta vulgaris, which gave the molecule its name).
Betaine hydrochloride is not the same product. It is a salt of betaine sold for an entirely different purpose, and the two are not interchangeable. A label that says only "betaine" without specifying which has not told you what is in the capsule. If you are buying TMG, look for the words betaine anhydrous or trimethylglycine on the nutrition panel, not just the front.
Per-capsule dose is the number that governs how you can use it
Two products can both say "1000mg per serving" and behave very differently. One is two 500mg capsules; the other is a single 1000mg tablet. The first lets you take 500mg alongside another formula without exceeding any stated dose; the second does not, short of cutting tablets. Since the main reason to buy a single-ingredient TMG is to control the amount you take alongside other products, the per-capsule figure matters more than the headline.
Single-ingredient or NMN combination?
TMG is most often bought by people who also take NMN. The stated rationale is that NMN is metabolised through pathways that consume methyl groups and TMG is a methyl donor — descriptive context, not a claim, and the pairing has never been tested as a product in a clinical trial. Two ways to buy it:
| Combination (NMN + TMG in one capsule) | Single-ingredient TMG | |
|---|---|---|
| Ratio | Fixed by the formula — ours are 750mg NMN : 750mg TMG | You set it, in 500mg steps |
| Pill count | Lower — one product covers both | Higher — two products if you also take NMN |
| Suits | People who want the standard pairing without thinking about it | People already on NMN from another product, or who want more or less TMG than 750mg |
| Claims | None authorised | None authorised at 1g |
There is no wrong answer here; it is a question of whether you want the ratio chosen for you. If you already take NMN + TMG or NMN Complete, adding a single-ingredient TMG is how you raise the TMG side without doubling the NMN.
Our TMG products, described plainly
TMG 1000mg
One active ingredient, two excipients (microcrystalline cellulose and the hypromellose capsule), no artificial colours, flavours or preservatives. 500mg capsules so the dose can be adjusted alongside other formulas. Third-party tested. At 1g a day it sits below the claim threshold and makes no claim.
View TMG 1000mgNMN + TMG 1500mg · NMN Complete 1600mg
Both fix the ratio at 750mg NMN to 750mg TMG per daily serving. NMN + TMG is the two-ingredient version; NMN Complete adds pterostilbene and apigenin. Note that NMN itself is under novel-food assessment in Great Britain (FSA reference RP-2116) — see the NMN guides for the current position. Neither product carries an authorised health claim.
View NMN + TMG View NMN CompleteWhat the evidence actually is
Betaine has a genuine research literature, and most of it uses daily doses of several grams — typically in athletic or clinical settings — well above the 1g common in UK capsule products. That gap is exactly why the authorised claim sits at 1.5g a day rather than at the dose most products sell. We do not summarise study outcomes here as benefits: doing so would be a health claim we are not permitted to make at our dose, and a summary written by the seller is the least reliable version you could read. The register position — one claim, conditional on 1.5g, with a 4g warning — is the honest summary of where the evidence has been judged to stand.
On the NMN pairing specifically: the methyl-group rationale is plausible biochemistry, and it is also unproven as a product. No trial has tested NMN + TMG as a combination, so any listing describing what the pair "does" is extrapolating.
How to read any TMG label
01 · Is the form stated? Betaine anhydrous or trimethylglycine on the nutrition panel. "Betaine" alone, or betaine HCl, is a different question.
02 · Are both figures printed? Milligrams per capsule and per daily serving. The per-capsule number is the one that governs how you can use it.
03 · Do the claims match the dose? Under 1.5g a day, no homocysteine or methylation wording is authorised. If it is there anyway, the seller is not reading the register — weigh the rest of the label accordingly.
04 · Single ingredient, or fully declared partners? A "methylation blend" with an undisclosed betaine dose cannot be assessed on any of the points above.
05 · Is the capsule material stated? Hypromellose or cellulose is plant-based; gelatin is not. "Vegetarian" on the front should be backed by the capsule line on the back.
06 · Independent testing and country of manufacture. Third-party tested, and a stated country of manufacture, are the minimum.