Nutrition6 min read
The supplements worth buying, and the ones that are not
The supplement aisle is built to make you feel like you are missing something. This is written for healthy adults aged 18 and over without a medical condition, and the list of products with solid evidence behind them is short enough to remember, none of them urgent.
The short answer
Supplements sit behind training, total energy intake and protein, not in front of them, and only a small number have useful evidence. Creatine monohydrate is the one with the strongest case for muscle and strength; protein powder is a convenience food that helps you reach a protein target you are missing, not a requirement; caffeine can help performance in a session rather than building muscle directly; vitamin D is a UK winter health matter. Most other products marketed for muscle growth have weak or poor evidence, and none of them is mandatory.
- Most "muscle-building" products on the shelf have weak evidence at best
The short list worth considering
These are the products with enough evidence behind them to be worth the money for a beginner, in the order most people would benefit from adding them.
| Supplement | What it does | Typical amount |
|---|---|---|
| Creatine monohydrate | Small but reliable gains in strength and training volume, plus evidence of a very small additional effect on muscle size itself when combined with lifting (Burke et al., 2023) | 3-5g a day, any time |
| Protein powder | Convenience: helps hit a protein target you are missing, and topping up protein that way does improve training gains (Morton et al., 2018) | 20-25g per scoop, as needed |
| Vitamin D | UK winter health advice, not a muscle supplement | 10 micrograms a day (Public Health England, 2016) |
| Caffeine | Better focus and effort in a session, not muscle growth | About 3-6mg per kg, roughly an hour before (Guest et al., 2021) |
| Evidence | Products | How to read it |
|---|---|---|
| Stronger, useful | Creatine monohydrate; protein powder where it helps you meet your total protein; caffeine for performance | Worth considering — creatine for muscle and strength, protein as convenience, caffeine for the session rather than for growth |
| Sound evidence, but for health rather than muscle | Vitamin D through the darker UK months | The UK autumn and winter recommendation rests on its own public health evidence; that evidence is about health, not about building muscle |
| Situational, for convenience rather than growth | Mass gainers; pre-workout blends | Calories in a shaker, or caffeine and company before a session — useful to some people on some days, never a requirement for muscle |
| Weak, not worth prioritising | BCAAs, testosterone boosters, glutamine, fat burners | Little or nothing to show for the money once protein and calories are adequate |
The ones you can skip
Most of the shelf falls into this group. Some of these do something measurable in a laboratory, but not enough to change what happens to a beginner training three times a week.
| Supplement | Why it is usually skippable |
|---|---|
| BCAAs | The same amino acids are already in the protein you eat, and total daily protein is what matters (Jager et al., 2017). A review of 24 studies in athletes and regular trainers found the effects on performance and body composition negligible, with less soreness the one fairly consistent finding; most of those studies did not report how much protein people ate, so the picture is incomplete rather than settled (Martinho et al., 2022) |
| Testosterone boosters | A review of 52 studies covering 27 marketed ingredients found most failed to raise total testosterone at all, with a few ingredient-specific exceptions (Morgado et al., 2024). That review measured hormones rather than muscle, so this is an absence of a convincing case rather than proof a product does nothing |
| Mass gainers | Eating enough energy does matter for muscle gain, though the ideal amount of extra energy is not established (Slater et al., 2019). A gainer is a convenient way to drink some of it if food is the obstacle; it is mostly carbohydrate you could buy more cheaply, and nothing about the powder is special |
| Glutamine | Pooled trials in adult athletes found no benefit for body composition or performance (Ramezani Ahmadi et al., 2019). That is about exercising adults, not the clinical uses glutamine also has |
| Fat burners | A fat-loss category rather than a muscle-building one. Formulations and evidence vary widely, and the stimulant doing most of the work is often just caffeine |
| Pre-workout blends | Some formulations can improve muscular endurance and mood in a session, with caffeine likely doing much of that work, but formulations and doses vary enormously and proprietary blends hide the amounts (Harty et al., 2018). Convenient for some people; not needed to build muscle |
If you are going to buy something, buy it in this order
Step 1
Nothing, for the first month
Get to the gym consistently and get your protein up first. That is where the results come from.
Step 2
Cheap, heavily studied, and the one product with evidence of a small effect on muscle size as well as strength. Plain monohydrate is fine; the fancier forms are not better.
Step 3
Protein powder, only if you are short
If you are consistently 30 or 40 grams under your target, a tub is easier than forcing another meal in.
Step 4
Vitamin D in winter
UK public health advice suggests 10 micrograms a day in autumn and winter for most adults (Public Health England, 2016). This is general health advice; it is not evidence that supplementing builds muscle in someone who is already sufficient.
Buying safely
In the UK, food supplements are regulated as food rather than medicine, so they are not licensed or sold as treatments and are not assessed the way a medicine is (Food Standards Agency, 2018). Sticking to plain, single-ingredient products from established retailers is a sensible precaution. We do not have a reliable figure for how often products are mislabelled or contaminated, so treat that as an unknown rather than a quantified risk.
- Prefer single ingredients over proprietary blends
- Look for batch-tested products if you are drug tested for sport
- Be wary of anything promising results that sound like medication
- Check with a pharmacist if you take prescribed medicines
How to judge a supplement claim yourself
You will meet new products faster than anyone can review them, so the useful skill is reading a claim rather than memorising a list. Four questions filter out almost everything on the shelf.
Step 1
Was it tested in people, doing the thing you want to do?
Cells in a dish and rats on a treadmill are where research starts, not where it finishes. A finding in trained or untrained adults lifting weights is what matters here.
Step 2
How large was the effect, in plain terms?
"Statistically significant" does not mean noticeable. Ask what it produced: an extra kilogram on a lift, or a difference nobody could feel.
Step 3
Does the tub contain the dose that was studied?
Proprietary blends often list an impressive ingredient at a fraction of the researched amount, which makes the label true and the product useless.
Step 4
Who paid for the study?
Manufacturer funding does not make research wrong, but independent replication is what turns a promising result into a reliable one.
The creatine worries that come up most
Creatine attracts more myths than the rest of the shelf combined, mostly because it has been around long enough to collect them. Here is what the position guidance and a review of common creatine questions actually say, and where the honest limits of that evidence sit (Kreider et al., 2017) (Antonio et al., 2021).
| Concern | What the evidence shows |
|---|---|
| It causes weight gain | Some early weight gain is water held inside muscle, typically around 1kg. It is not fat. |
| It damages the kidneys | Pooled trials found a rise in a blood marker called creatinine, which is a by-product of creatine itself. Because the usual kidney-function estimate is calculated from that marker, the estimate drops too, yet when filtration was measured by a method that does not depend on creatinine it did not change (de Souza Almeida et al., 2026). Trials in people with kidney disease that is not treated by dialysis are missing entirely, so if you have a kidney condition, an abnormal kidney test, or have been told to monitor your kidneys, ask your doctor before taking it. |
| It causes hair loss | The worry came from one small unreplicated study. A 12-week trial that measured hair density and thickness directly found no difference between creatine and a placebo (Lak et al., 2025). One short trial in young men is reassuring rather than final. |
| You need to load | A loading phase only fills muscle stores faster. 3 to 5g a day gets to the same place in three to four weeks. |
| It only works for men | Benefits have been shown in both men and women; the mechanism is not sex-specific. |
People also ask
Do I need supplements to build muscle as a beginner?
No. Muscle is built by training that gets progressively harder and by eating enough protein and calories. Supplements can make small differences at the edges, but none of them are required and none of them work without the training.
Which supplement has the strongest evidence for muscle growth?
Creatine monohydrate. It is one of the most studied sports supplements there is, and it produces small but consistent improvements in strength and training volume, which over months adds up to more muscle.
Are BCAAs worth buying?
Not if you eat enough protein. Branched-chain amino acids are already present in the protein you eat, and studies giving them to people on adequate protein intakes find no meaningful extra benefit.
Is a pre-workout better than a coffee?
For most people, no. The active ingredient doing the work is usually caffeine, and a strong coffee delivers it for a fraction of the price. Pre-workouts are convenient rather than superior.
Should I take a mass gainer if I struggle to eat enough?
It is usually cheaper to make your own with oats, milk, peanut butter and a banana. Mass gainers are mostly maltodextrin and cost several times what the equivalent food does, though they can be useful when you genuinely cannot face eating.
References
- Antonio, J., Candow, D.G., Forbes, S.C., Gualano, B., Jagim, A.R., Kreider, R.B., et al. (2021) 'Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show?', Journal of the International Society of Sports Nutrition, 18, article 13. doi: 10.1186/s12970-021-00412-w. Available at: https://jissn.biomedcentral.com/articles/10.1186/s12970-021-00412-w
- Burke, R., Pinero, A., Coleman, M., Mohan, A., Sapuppo, M., Augustin, F., et al. (2023) 'The effects of creatine supplementation combined with resistance training on regional measures of muscle hypertrophy: a systematic review with meta-analysis', Nutrients, 15(9), article 2116. doi: 10.3390/nu15092116. Available at: https://pubmed.ncbi.nlm.nih.gov/37432300/
- de Souza Almeida, A., Dias da Silva, L.O., Abe Takahasi, B.N., Damico Terada, B., Alvarez Goncalves, F.G., Cordeiro Porto, B., et al. (2026) 'Impact of creatine supplementation on kidney health: a systematic review and meta-analysis', International Urology and Nephrology. doi: 10.1007/s11255-026-05287-x. Available at: https://link.springer.com/article/10.1007/s11255-026-05287-x
- Food Standards Agency (2018) Food supplements. Available at: https://www.food.gov.uk/business-guidance/food-supplements (Accessed: 23 August 2026).
- Guest, N.S., VanDusseldorp, T.A., Nelson, M.T., Grgic, J., Schoenfeld, B.J., Jenkins, N.D.M., et al. (2021) 'International society of sports nutrition position stand: caffeine and exercise performance', Journal of the International Society of Sports Nutrition, 18, article 1. doi: 10.1186/s12970-020-00383-4. Available at: https://pubmed.ncbi.nlm.nih.gov/33388079/
- Harty, P.S., Zabriskie, H.A., Erickson, J.L., Molling, P.E., Kerksick, C.M. and Jagim, A.R. (2018) 'Multi-ingredient pre-workout supplements, safety implications, and performance outcomes: a brief review', Journal of the International Society of Sports Nutrition, 15(1), article 41. doi: 10.1186/s12970-018-0247-6. Available at: https://pubmed.ncbi.nlm.nih.gov/30089501/
- Jager, R., Kerksick, C.M., Campbell, B.I., Cribb, P.J., Wells, S.D., Skwiat, T.M., et al. (2017) 'International Society of Sports Nutrition position stand: protein and exercise', Journal of the International Society of Sports Nutrition, 14, article 20. doi: 10.1186/s12970-017-0177-8. Available at: https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0177-8
- Kreider, R.B., Kalman, D.S., Antonio, J., Ziegenfuss, T.N., Wildman, R., Collins, R., et al. (2017) '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, 14, article 18. doi: 10.1186/s12970-017-0173-z. Available at: https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0173-z
- Lak, M., Forbes, S.C., Ashtary-Larky, D., Dadkhahfar, S., Robati, R.M., Nezakati, F., et al. (2025) 'Does creatine cause hair loss? A 12-week randomized controlled trial', Journal of the International Society of Sports Nutrition, 22(sup1), article 2495229. doi: 10.1080/15502783.2025.2495229. Available at: https://pubmed.ncbi.nlm.nih.gov/40265319/
- Martinho, D.V., Nobari, H., Faria, A., Field, A., Duarte, D. and Sarmento, H. (2022) 'Oral branched-chain amino acids supplementation in athletes: a systematic review', Nutrients, 14(19), article 4002. doi: 10.3390/nu14194002. Available at: https://pubmed.ncbi.nlm.nih.gov/36235655/
- Morgado, A., Tsampoukas, G., Sokolakis, I., Schoentgen, N., Urkmez, A. and Sarikaya, S. (2024) 'Do "testosterone boosters" really increase serum total testosterone? A systematic review', International Journal of Impotence Research, 36(4), pp. 348-364. doi: 10.1038/s41443-023-00763-9. Available at: https://pubmed.ncbi.nlm.nih.gov/37697053/
- Morton, R.W., Murphy, K.T., McKellar, S.R., Schoenfeld, B.J., Henselmans, M., Helms, E., et al. (2018) 'A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults', British Journal of Sports Medicine, 52(6), pp. 376-384. doi: 10.1136/bjsports-2017-097608. Available at: https://pubmed.ncbi.nlm.nih.gov/28698222/
- Public Health England (2016) PHE publishes new advice on vitamin D. London: Public Health England. Available at: https://www.gov.uk/government/news/phe-publishes-new-advice-on-vitamin-d (Accessed: 23 August 2026).
- Ramezani Ahmadi, A., Rayyani, E., Bahreini, M. and Mansoori, A. (2019) 'The effect of glutamine supplementation on athletic performance, body composition, and immune function: a systematic review and a meta-analysis of clinical trials', Clinical Nutrition, 38(3), pp. 1076-1091. doi: 10.1016/j.clnu.2018.05.001. Available at: https://pubmed.ncbi.nlm.nih.gov/29784526/
- Slater, G.J., Dieter, B.P., Marsh, D.J., Helms, E.R., Shaw, G. and Iraki, J. (2019) 'Is an energy surplus required to maximize skeletal muscle hypertrophy associated with resistance training?', Frontiers in Nutrition, 6, article 131. doi: 10.3389/fnut.2019.00131. Available at: https://pubmed.ncbi.nlm.nih.gov/31482093/
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Educational information for adults aged 18 and over. It does not diagnose, treat or manage any medical condition. If you have a health condition, or symptoms that worry you, speak to your doctor or a health professional.