Reviewed and updated: 9 October 2026
Is TMG better than creatine? In a word, no, and the reason is that they do two quite different jobs, so neither one is a like-for-like swap for the other. Creatine is the better-studied of the two by a very long way and has the stronger track record for training performance. TMG, also called trimethylglycine or betaine, is a methyl donor that the body uses in its own chemistry, and the research on it for exercise is much thinner and more mixed. I want to take you through both properly, because the way these two get compared online usually leaves out the most interesting bit: they are actually connected.
I should say up front that I sell both ingredients in different products, so you should read this knowing that. What follows is the comparison I would want to read myself before spending money, which means being just as clear about what the trials did not find as about what they did.
Is TMG better than creatine? The short answer
- What they are: creatine is a small molecule your muscles use to recycle energy during short, hard efforts. TMG is glycine carrying three methyl groups, which the body uses to hand methyl groups to other reactions, including the one that makes creatine in the first place.
- Which has more evidence: creatine, comfortably. It has decades of trials behind it and a large position stand from the International Society of Sports Nutrition. TMG has a smaller body of work, and the results are mixed.
- Are they substitutes: no. In one head-to-head trial, creatine raised muscle phosphocreatine and improved strength and power, while betaine did not, and adding betaine to creatine made no extra difference.
- Can you take them together: yes, nothing in the research suggests a problem, but the trial that tested the pairing found no added benefit from the TMG.
- One honest caution: at high intakes (around 6 g a day for six weeks), betaine raised LDL cholesterol in healthy volunteers. That is one reason to approach large doses with respect.
What TMG actually is
TMG stands for trimethylglycine. You will also see it sold as betaine, betaine anhydrous or glycine betaine, and all of those names describe the same molecule. It was first isolated from sugar beet, which is where the name "betaine" comes from, and it is still found in beetroot today. Chemically it is the amino acid glycine with three methyl groups attached. A methyl group is a small carbon-and-hydrogen unit that the body moves from molecule to molecule as part of everyday metabolism.
That is why TMG is described as a methyl donor. In the liver and kidneys, an enzyme called betaine-homocysteine methyltransferase takes one of those methyl groups from TMG and hands it to homocysteine, turning it back into methionine. Methionine is then used to make S-adenosylmethionine, usually shortened to SAMe, which is the body's main general-purpose methyl donor. If you picture methyl groups as a kind of small change used all over the cell, TMG is one of the ways the body tops up its pocket.
Separately, TMG is an osmolyte. Cells use it to hold water and stay stable under stress, which is the property that attracted early interest from sports researchers. That is a plausible reason to study it in exercise, but plausible is not the same as demonstrated, and it is worth keeping the two apart as you read on.
What creatine actually is, and why it has the reputation it does
Creatine is made from three amino acids: arginine, glycine and methionine. Your body makes some itself, mostly in the kidneys and liver, and you take in a little more from meat and fish. About 95 per cent of the body's creatine sits in skeletal muscle, where much of it is stored as phosphocreatine. During a short, hard effort like a heavy set, a sprint or a jump, phosphocreatine is used to rapidly re-form ATP, the molecule that powers muscle contraction. A larger store of phosphocreatine simply means that system can keep going a little longer before other energy pathways have to take over.
The research on supplementing it is the deepest of any sports ingredient. The International Society of Sports Nutrition position stand concludes that supplementation consistently increases intramuscular creatine, which may help explain the improvements seen in high-intensity exercise performance and training adaptations, and that short and long-term supplementation, at up to 30 g a day for five years, was safe and well tolerated in healthy people (Kreider et al., Journal of the International Society of Sports Nutrition, 2017). The same paper notes that significant health benefits may come from ensuring habitual low dietary creatine intake, around 3 g a day, throughout life.
On the label side, creatine is one of the few ingredients with specific wording attached: creatine increases physical performance in successive bursts of short-term, high-intensity exercise, with the effect obtained from a daily intake of 3 g. If you want the full picture of how it works and how to take it, I have written it up in what creatine is and how it works and creatine timing and usage.
The link nobody mentions: TMG, methyl groups and your own creatine
Here is the part that makes this comparison more interesting than a simple head-to-head. Making creatine is a methyl-hungry process. The last step turns guanidinoacetate into creatine, and it uses a methyl group taken from SAMe. A review of methyl balance in humans concluded that the quantitatively most important SAMe-dependent methylation pathways in mammals are the synthesis of creatine, of phosphatidylcholine and of sarcosine (Mudd et al., American Journal of Clinical Nutrition, 2007). Animal work points the same way. In neonatal piglets, creatine synthesis was shown to place very large demands on arginine and methionine metabolism, and the liver there carried the enzyme that uses betaine to recycle homocysteine into methionine (Brosnan et al., Journal of Nutrition, 2009). That is animal work, so I would not stretch it to adult humans, but it shows why the idea hangs together.
So the theory behind "TMG for creatine" goes like this: TMG helps keep methyl groups available, methyl groups are needed to make creatine, so perhaps extra TMG would support the body's own creatine production. It is a neat chain of logic. The important word is "perhaps", because a neat chain of logic in biochemistry is a reason to run a trial and not a result in itself.
When researchers did run that trial, it did not come out the way the theory suggested, and I will take you through it in the next section. The bigger point here is simply that TMG and creatine are connected as supply chain and finished product, which is exactly why one cannot stand in for the other. Giving the body the raw material for making something is not the same as giving it the thing.
What the research says about TMG and exercise
The head-to-head trial: creatine against betaine
The most useful single study for this question is a double-blind, randomised, placebo-controlled trial in untrained volunteers. Participants were assigned to betaine (2 g a day), creatine (20 g a day, a loading dose), both together, or placebo, and were tested after 10 days. Muscle phosphocreatine content rose in the creatine and creatine-plus-betaine groups, but not in the betaine-only group. Creatine also improved squat and bench press power and one-repetition-max strength, whereas betaine alone made no significant difference to strength or power compared with placebo, and adding betaine to creatine did not do any better than creatine on its own (Del Favero et al., Amino Acids, 2012).
The authors' own title says it plainly: creatine, but not betaine, increased muscle phosphorylcreatine content and strength performance. Two caveats are worth keeping in mind. This was a short trial, and it involved people who were not training regularly, so it cannot tell us what happens over months in experienced lifters. But as direct evidence on the specific question of whether TMG does what creatine does, it points firmly one way.
Pooling the trials: a modest signal with wide error bars
Looking at betaine on its own, a 2017 systematic review of randomised trials in healthy participants found seven studies that were all rated as excellent quality on the PEDro scale. Only two reported increases in strength or power, with gains of up to about 25 per cent in one outcome, and the other five found no change in any strength or power measure (Ismaeel, Journal of Strength and Conditioning Research, 2017). The author concluded that there was a lack of evidence for a clear ergogenic effect, while noting that those two positive studies justified further research.
A more recent systematic review and meta-analysis pooled 17 studies with 317 participants, about a fifth of them women, all comparing chronic betaine (at least seven days) with placebo. It found a significant effect on maximal strength, with an effect size of 0.47 (95% confidence interval 0.04 to 0.89), driven mostly by lower-body strength (0.49, 95% CI 0.01 to 0.98). There were no significant effects on upper-body strength, cycling sprint power, bench press throw power or muscular endurance, and vertical jump only reached significance after one low-quality study was excluded (Zawieja et al., Journal of Sports Sciences, 2024).
I find that result worth reading slowly. It is a real signal, and I would not wave it away. But the lower end of those confidence intervals sits very close to zero, the effects were confined to some outcomes and absent in others, and the studies used different doses and populations. A fair summary is that betaine may have a small effect on maximal strength in some people, and that the evidence is a good deal less settled than it is for creatine.
Why the results are so mixed
There are a few likely reasons, and none of them is a mystery. The trials use different amounts, different durations and different kinds of participants, from untrained students to trained athletes. Betaine studies are also generally small. And if the proposed mechanism is partly about cell hydration and methyl supply rather than a direct store of fuel, you would expect any effect to be subtler and more variable than the effect of loading muscle with phosphocreatine. The honest position is that TMG is an interesting ingredient with a plausible rationale and an unfinished evidence base.
Side by side: how the two compare on the evidence
Taking the studies together, here is how I would sum up the comparison in plain terms. Creatine has consistent evidence that supplementation raises intramuscular creatine and supports high-intensity training performance, and a long safety record in healthy people. TMG has mixed evidence, with some pooled analyses showing a small effect on maximal strength and a head-to-head trial showing none, and with tolerability that depends on the amount.
On mechanism, creatine acts directly as a store of high-energy phosphate in muscle, while TMG works indirectly as a methyl donor and osmolyte. On dose, creatine's useful range is a few grams a day, whereas TMG studies span a much wider range of amounts. On cost, creatine monohydrate is one of the cheapest ingredients in sports nutrition, which matters if you are choosing between them on value alone.
Put it that way and the question changes. It stops being "which is better" and becomes "what am I actually trying to do?" If your goal is to support training performance in short, hard efforts, creatine is the ingredient with the evidence. If you are looking at TMG, it is usually because it is part of a formula for another reason, or because you are curious about methyl donors in general.
How much: label amounts and the doses used in studies
For creatine, the amount attached to the performance wording is 3 g a day, and that is also the maintenance figure the position stand discusses. Some people use a short loading phase first, as in the 20 g a day trial above, but loading is optional, and a steady 3 to 5 g a day gets muscle stores to the same place over a few weeks. I have covered the options in creatine loading, dosing and saturation.
For TMG, the picture is looser. Most of the exercise trials I have seen use a few grams a day, often split across the day; the head-to-head trial above used 2 g. Supplements range from a few hundred milligrams per serving, as in multi-ingredient formulas, up to a gram or more per serving in stand-alone TMG products. The study that found a rise in LDL cholesterol used 6 g a day, which is a lot more than a typical label serving.
Typical diets provide some betaine already. Intake estimates vary a lot depending on how much wheat, spinach and beetroot you eat, which is part of why defining a precise "deficiency" or a precise target is difficult. I am not aware of an official tolerable upper intake level for betaine from UK authorities, so the sensible approach is to stay at or below the amount on the label and to be cautious about anything approaching the multi-gram doses used in research.
One point on wording: the Great Britain register lists a claim for betaine relating to normal homocysteine metabolism, tied to an intake of 1.5 g a day. That is a different job from exercise performance, and it is well above the amount in a typical multi-ingredient capsule, so I do not attach it to any of our products. Nothing on the register links betaine with physical performance.
Can you take TMG and creatine together?
Yes, there is no known interaction between the two, and people do take them alongside each other. The combination was tested directly in the trial I described earlier, where betaine plus creatine produced the same improvements as creatine alone. That tells you two useful things at once: the pairing was fine, and the TMG was not adding anything measurable on top in that setting.
If you already take creatine and you find TMG in a formula you like for other reasons, you do not need to rearrange your routine. Creatine mixes into water or a shake and can be taken at whatever time of day you find easiest to remember, as I explain in creatine timing and usage. TMG is best taken with food, since it can be hard on an empty stomach for some people. There is no need to match the two to the minute.
Which should you choose?
If I put myself in your shoes and the goal is supporting training, I would start with creatine monohydrate. It is inexpensive, the research is extensive, and the authorised wording is specific to exactly this use. Take 3 g a day, give it a few weeks to saturate, and judge it on your own training log. If you want to see what we offer, our micronised creatine monohydrate is a plain, single-ingredient powder with nothing added.
If you are curious about TMG, I would see it as a separate question rather than as an upgrade or an alternative. It makes sense as part of a considered formula, and it is easy to find in foods, but the exercise evidence does not justify buying a large tub in the hope that it replaces creatine. And if you have been told by a doctor to take betaine for a medical reason, that is a prescription matter and sits outside anything I would suggest here.
There is a middle path that fits some people: creatine as the performance ingredient, and a modest amount of TMG only if it arrives as part of a formula you have chosen for its other contents. That is exactly how I think about it in our own range.
Where TMG sits in our NMN formula, and why
The reason we use TMG at all is not exercise. Our NMN formula pairs 500mg of NMN with 500mg of TMG, matched one to one, because NMN metabolism runs through a methylation-dependent pathway, and many experienced users buy TMG as a separate bottle to take alongside. I wrote about that pairing, and the thinking behind it, in NMN with TMG and resveratrol, and when to take it. It sits there as a supporting ingredient in a multi-ingredient capsule. It is not there as a replacement for creatine, and I would not describe it that way.
If you want the wider context on NMN itself, including where it stands in Great Britain, where it is currently a novel food that has not completed authorisation, the places to start are what NAD+ is and why it matters, NMN versus NR and whether NMN is worth taking. The full buyer's overview is how to choose an NMN supplement in the UK.
Shop NMN Fusion Pro with 500mg TMG
Natural food sources of TMG (and creatine)
Food gives you both, in different places. For TMG, wheat bran and wheat germ are among the richest sources, followed by spinach, beetroot and quinoa, with shellfish also contributing. In a typical UK diet, wholemeal bread, breakfast cereals made with wheat bran and a few portions of leafy greens or beetroot add up to a meaningful share of daily intake without any supplement.
Creatine comes almost entirely from animal foods, mainly red meat and fish. A varied omnivorous diet supplies something like one to two grams a day, and vegetarians and vegans start from a lower baseline because their diets contain little or none. That is one reason creatine tends to be studied in those groups too.
How to read a TMG label
A few details are worth checking before you buy. First, look at the name: "trimethylglycine", "TMG" and "betaine anhydrous" are the same ingredient, but "betaine HCl" (hydrochloride) is a different product, usually sold for a different purpose, and it is not the same thing at all. Second, look at the amount per serving, not per pouch, and check how many capsules or scoops make up a serving so you are comparing like with like.
Third, be wary of "proprietary blend" panels that hide how much TMG is actually in there. In ours, every active is listed with its own amount, so you can compare line by line. Fourth, look at the quality wording. We say our products are formulated in the UK and tested for purity and heavy metals at our GMP-certified facility, and certificates of analysis are available on request; whichever brand you choose, I would want a clear statement of that kind rather than vague talk of "premium" or "pharmaceutical grade".
A few cautions worth knowing
TMG is generally well tolerated at label amounts, but some people notice stomach upset, nausea or loose stools, particularly at higher intakes or on an empty stomach. Starting with food and a smaller amount usually helps. As noted above, a trial in healthy volunteers found that 6 g a day for six weeks raised LDL cholesterol by about 0.36 mmol/l and triglycerides by about 0.14 mmol/l relative to placebo, and lower doses also raised LDL, though not by a statistically significant amount (Olthof et al., PLoS Medicine, 2005). If you have raised cholesterol or take cholesterol-lowering medication, speak to your GP or pharmacist before using TMG supplements.
Please also speak to a healthcare professional first if you are pregnant or breastfeeding, if you take regular medication, or if you have a kidney or liver condition. Creatine has a strong safety record in healthy adults, but anyone with a kidney problem should get advice before using it, and it is sensible to drink fluids regularly while you take it. Neither ingredient is intended for anyone under 18.
What to realistically expect
With creatine, expect something modest and cumulative: a few weeks of steady use to fill muscle stores, then possibly a little extra work capacity in short, hard efforts, alongside a training plan that is doing the real heavy lifting. A small, early rise on the scale of a kilo or so can come from water held in muscle, which is normal and worth knowing about.
With TMG, expect very little that you will notice, and regard any change as a bonus. The research suggests a possible small effect on maximal strength in some trials, and no effect in others. Sleep, protein, training quality and consistency will move the needle far more than either ingredient, and if you take only one thing from this article, I would make it that.
Frequently asked questions
Is TMG better than creatine?
No. They do different jobs, and creatine has far stronger evidence for supporting short, high-intensity training performance. In a head-to-head trial, creatine raised muscle phosphocreatine and improved strength and power, while betaine did not.
Does TMG work like creatine?
No. Creatine acts as a store of high-energy phosphate in muscle. TMG is a methyl donor and osmolyte that the body uses in several different reactions, one of which is the synthesis of creatine itself. Supplying a raw material is not the same as supplying the finished product.
Can I take TMG and creatine together?
Yes. There is no known interaction. In the one trial that tested the combination, adding betaine to creatine produced the same results as creatine alone, so the TMG added nothing measurable on top.
How much TMG should I take?
Follow the amount on the label. Studies on exercise have mostly used a few grams a day, and one trial that used 6 g a day found a rise in LDL cholesterol, so large amounts are best approached with caution and a conversation with your GP or pharmacist.
Is TMG the same as betaine?
Yes. TMG, trimethylglycine, betaine anhydrous and glycine betaine are the same molecule. Betaine HCl is a different product and should not be confused with it.
When should I take TMG?
With food, at a time you can remember. There is no research that makes one time of day clearly better than another, and taking it with a meal tends to be gentler on the stomach.
Is creatine safe?
In healthy adults, the evidence is reassuring: the International Society of Sports Nutrition position stand reports that up to 30 g a day for five years was safe and well tolerated. People with kidney problems should seek advice first.
Sources
- Kreider R.B. et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 2017. https://doi.org/10.1186/s12970-017-0173-z
- Del Favero S. et al. Creatine but not betaine supplementation increases muscle phosphorylcreatine content and strength performance. Amino Acids, 2012. https://doi.org/10.1007/s00726-011-0972-5
- Zawieja E. et al. Effects of chronic betaine supplementation on exercise performance: systematic review and meta-analysis. Journal of Sports Sciences, 2024. https://doi.org/10.1080/02640414.2024.2423578
- Ismaeel A. Effects of betaine supplementation on muscle strength and power: a systematic review. Journal of Strength and Conditioning Research, 2017. https://doi.org/10.1519/JSC.0000000000001959
- Olthof M.R. et al. Effect of homocysteine-lowering nutrients on blood lipids: results from four randomised, placebo-controlled studies in healthy humans. PLoS Medicine, 2005. https://doi.org/10.1371/journal.pmed.0020135
- Mudd S.H. et al. Methyl balance and transmethylation fluxes in humans. American Journal of Clinical Nutrition, 2007. https://doi.org/10.1093/ajcn/85.1.19
- Brosnan J.T. et al. Creatine synthesis is a major metabolic process in neonatal piglets and has important implications for amino acid metabolism and methyl balance. Journal of Nutrition, 2009. https://doi.org/10.3945/jn.109.105411
Study findings above are reported as science and describe what researchers measured in those trials. They are not statements about what any supplement will do for you.
Thank you for reading this one properly. If you would like to browse the rest of our guides, they are all gathered in the Pure Vitamins UK supplement guides, and everything starts from the Pure Vitamins UK home page.
Dr. Miron, Founder of Pure Vitamins UK
A food supplement is not a substitute for a varied, balanced diet and a healthy lifestyle. This article is general information and not medical advice. Speak to your GP or pharmacist before starting a new supplement, particularly if you take medication, have a health condition, or are pregnant or breastfeeding.
