Creatine or HMB: what is the difference
Creatine and HMB are often advertised as “supplements for muscle growth,” but they work in completely different ways. Our editors examined where each substance comes from, which process in the muscle it affects, how convincing the studies are and which myths around them have no basis.
Two different molecules with different histories
Creatine and HMB (beta-hydroxy-beta-methylbutyrate) often stand on the same shelf of a sports store, and buyers perceive them as interchangeable “muscle supplements.” In reality these are substances with different origins, different biochemistry and a very different level of evidence. Our editors explain how they differ in essence rather than by marketing promises.
Creatine is a nitrogen-containing organic acid that the body synthesizes from three amino acids: arginine, glycine and methionine. A person covers about half the daily requirement through their own synthesis in the liver and kidneys, and gets the rest from meat and fish. More than 90% of creatine stores are concentrated in skeletal muscles.
HMB is a metabolite of the essential amino acid leucine. Only a small fraction of leucine, by various estimates about 5%, is converted in the body into HMB. Therefore it is practically impossible to obtain appreciable amounts of HMB from food: this would require very large volumes of protein products.
Historically, creatine became a mass supplement after the 1992 Olympic Games, while HMB drew attention after studies by Steven Nissen’s group in the mid-1990s. Since then creatine has received hundreds of controlled studies, whereas the body of data on HMB is far smaller and more contradictory.
Mechanism of action: energy versus protein protection
The main difference is in the point of application. Creatine works as an energy buffer. In the muscle it exists mainly in the form of creatine phosphate, which, with the participation of creatine kinase, quickly restores ATP during short intense efforts. Taking the supplement raises intramuscular stores of creatine and creatine phosphate.
A larger store of creatine phosphate means that an athlete can perform slightly more repetitions in a set or recover faster between sprints. It is precisely the increase in the volume of quality work that over time translates into gains in strength and muscle mass. Additionally, creatine increases the water content in muscle cells, which is also considered one of the signals for growth.
HMB acts differently: it is regarded as an anticatabolic agent. It is assumed to reduce the breakdown of muscle protein (in particular through the ubiquitin-proteasome pathway), somewhat stimulate protein synthesis through mTOR and participate in stabilizing cell membranes as a precursor of cholesterol in muscle cells.
Thus creatine helps to train more intensely, while HMB theoretically helps to lose less muscle tissue under stress. This difference explains why the effect of creatine is noticeable in almost any trained athlete, whereas the effect of HMB is best manifested where catabolism is pronounced: in beginners, the elderly, during immobilization.
- Creatine:ATP resynthesis, increased training volume, cell hydration.
- HMB:reduction of proteolysis, moderate stimulation of protein synthesis, possible membrane stabilization.
What the studies say
Creatine monohydrate is one of the few supplements that the 2018 consensus of the International Olympic Committee classifies among agents with good evidence of efficacy. Meta-analyses record gains in strength and lean mass when combined with strength training, in both men and women, in the young and the elderly.
For HMB the picture is less clear-cut. Nissen’s early works showed a reduction in markers of muscle damage and gains in strength in untrained people. However, the 2009 meta-analysis by Rowlands and Thomson concluded that in trained athletes the effect on strength and body composition is small or trivial.
The ISSN position on HMB (2013) is more optimistic, but some of the positive studies, especially with free-acid HMB, later came under criticism because of atypically large effects that independent groups failed to reproduce. Our editors consider it appropriate to treat these results with caution.
The practical bottom line: creatine has a stable, reproducible effect; HMB a small and context-dependent one. This does not make HMB useless, but it moves it from the category of “basic” to the category of “situational” supplements.
Comparison table
To summarize the differences, we have compiled the key parameters into a table. It does not replace an individual consultation, but it allows you to quickly get oriented in exactly how these two substances differ.
| Parameter | Creatine monohydrate | HMB |
|---|---|---|
| Origin | Synthesis from arginine, glycine, methionine; meat, fish | Metabolite of leucine |
| Main mechanism | Creatine phosphate buffer, ATP resynthesis | Anticatabolic, reduction of proteolysis |
| Typical dose in studies | 3–5 g/day (or loading of ~20 g/day for 5–7 days) | 3 g/day, more often in 2–3 doses |
| Evidence in trained individuals | High | Low or contradictory |
| Change in body weight | Often +1–2 kg due to water at the start | Not typical |
| Cost of an effective dose | Low | Higher |
Note the difference in cost: creatine monohydrate is one of the cheapest supplements per daily dose, whereas an effective dose of HMB usually costs several times more. With a weaker evidence base, this is a substantial argument.
Another nuance is the forms. For creatine the “gold standard” remains the monohydrate; more expensive forms (hydrochloride, buffered creatine) have not proven advantages in comparative studies. HMB is produced as a calcium salt (HMB-Ca) and a free acid (HMB-FA), and the second form is absorbed faster, although an advantage for the result has not been proven.
Finally, both substances are not doping and are not on the WADA Prohibited List. However, for athletes who undergo testing it is important to choose products with independent certification, since the risk of contamination applies to any supplements.
Safety and common myths
Creatine is one of the best-studied supplements from the standpoint of safety. In healthy people at recommended doses, no harm to the kidneys or liver has been found. At the same time creatine raises the level of creatinine in the blood, which can be mistakenly interpreted as a worsening of kidney function, so the doctor should be informed of its use before tests.
The widespread myth that creatine “dehydrates” and causes cramps is not confirmed by studies. Likewise there is no evidence that it causes baldness: the well-known study with an increase in dihydrotestosterone in rugby players did not measure hair loss and has still not been reproduced.
HMB also has a favorable safety profile: in studies with doses up to 6 g per day no serious side effects were recorded. Mild stomach discomfort is sometimes mentioned. People with kidney or liver diseases, as with creatine, need a doctor’s consultation.
Another myth is that HMB and creatine allegedly “conflict” with each other. There are no data on a negative interaction; several studies examined their combination, but an additional benefit from HMB on top of creatine in trained people has not been convincingly shown.
Editorial conclusions
Creatine and HMB are not analogs but substances with different tasks. Creatine enhances the energy supply of short intense efforts and has one of the strongest evidence bases among sports supplements.
HMB is aimed at reducing the breakdown of muscle protein. Its effect in trained athletes is small, and it is most interesting for situations of pronounced catabolism — for example, in old age or during a forced break from training.
If the budget is limited and the goal is strength and muscle mass, it is reasonable to start with creatine monohydrate. HMB should be regarded as an additional, situational tool, not a replacement.
For a deeper understanding of the topic we recommend our materials on the forms of creatine and their differences, on leucine and muscle protein synthesis, as well as on the safety of creatine for the kidneys.
References
- Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18.
- Wilson JM, Fitschen PJ, Campbell B, et al. International Society of Sports Nutrition Position Stand: beta-hydroxy-beta-methylbutyrate (HMB). J Int Soc Sports Nutr. 2013;10(1):6.
- Maughan RJ, Burke LM, Dvorak J, et al. IOC consensus statement: dietary supplements and the high-performance athlete. Br J Sports Med. 2018;52(7):439–455.
- Rowlands DS, Thomson JS. Effects of beta-hydroxy-beta-methylbutyrate supplementation during resistance training on strength, body composition, and muscle damage in trained and untrained young men: a meta-analysis. J Strength Cond Res. 2009;23(3):836–846.
- Nissen S, Sharp R, Ray M, et al. Effect of leucine metabolite β-hydroxy-β-methylbutyrate on muscle metabolism during resistance-exercise training. J Appl Physiol. 1996;81(5):2095–2104.
- Lanhers C, Pereira B, Naughton G, et al. Creatine supplementation and lower limb strength performance: a systematic review and meta-analyses. Sports Med. 2015;45(9):1285–1294.
Andriy Melnyk
A strength-sports coach and author of programs for beginner and intermediate levels. Writes about training planning.
