Supplements That Actually Work
The list of supplements with solid evidence behind them is short. Here it is, along with the much longer list of things not worth your money.
Last updated: 1 July 2026
Overview
The supplement industry is large, lightly regulated, and built on the gap between what people hope works and what has been shown to.
The genuinely useful list is short enough to fit in a paragraph. Everything else ranges from mildly promising to actively pointless.
Quick Answer
The supplements with the strongest evidence for training are creatine monohydrate, caffeine, protein powder as a food convenience, and vitamin D where a deficiency exists. Most other performance supplements, including BCAAs, testosterone boosters and fat burners, have little or no supporting evidence.
Key Points
- Creatine and caffeine are the only two with strong performance evidence.
- Protein powder is convenient food, not a performance supplement.
- Vitamin D matters only if you are deficient, which many people in northern climates are.
- BCAAs are redundant if you eat enough total protein.
- Fat burners produce trivial effects at best.
The short list
| Supplement | Evidence | Typical dose |
|---|---|---|
| Creatine monohydrate | Strong | 3 to 5g daily |
| Caffeine | Strong | 3 to 6mg per kg, 45 to 60 min before |
| Protein powder | Strong as food, neutral as a supplement | As needed to hit protein target |
| Vitamin D | Strong if deficient | 10 to 25 micrograms daily in winter |
| Omega 3 | Moderate, mainly general health | 1 to 2g combined EPA and DHA |
Public health advice in the UK is to consider a daily vitamin D supplement during autumn and winter, since sunlight is insufficient to produce enough at those latitudes.
The long list of things that do not do much
| Supplement | The claim | The reality |
|---|---|---|
| BCAAs | Muscle growth, reduced soreness | Redundant if total protein is adequate |
| Testosterone boosters | Raise testosterone | No meaningful effect in healthy men |
| Fat burners | Accelerate fat loss | Effects are trivial, mostly caffeine |
| Glutamine | Recovery, immunity | No benefit in healthy trained people |
| Mass gainers | Muscle gain | Expensive calories, food is cheaper |
| Detox products | Remove toxins | Your liver and kidneys already do this |
| Pre-workout blends | Multiple benefits | Usually caffeine plus expensive filler |
Most pre-workout products are caffeine with additions that either do nothing or are present at doses too low to matter. Caffeine alone is far cheaper and equally effective.
Caffeine, used properly
| Aspect | Guidance |
|---|---|
| Dose | 3 to 6mg per kg bodyweight |
| Timing | 45 to 60 minutes before training |
| Tolerance | Builds within one to two weeks of daily use |
| Cut-off | At least 8 hours before bed |
| Caution | Sleep loss will cost you more than caffeine gains |
Caffeine improves endurance, perceived effort and, to a smaller degree, strength output. If you use it every day for every session, you lose most of the acute benefit and keep the sleep disruption.
How to judge a claim yourself
- -Is there human research, or only cell and rodent studies?
- -Is the dose in the product the same as the dose in the studies?
- -Was the research funded by the company selling it?
- -Does the marketing rely on a mechanism rather than an outcome?
- -Would the effect be visible without the supplement, given good training and food?
The final question filters most of the market. No supplement compensates for inconsistent training, inadequate protein or insufficient sleep.
Common Mistakes
| Mistake | Why it causes problems | Better approach |
|---|---|---|
| Buying supplements before fixing sleep and food | Small effect chasing large problems | Fix the basics first |
| Proprietary blends | Doses are hidden, usually because they are low | Buy single ingredients |
| Daily high dose caffeine | Tolerance plus sleep disruption | Use it strategically |
| BCAAs alongside a high protein diet | Paying for amino acids you already eat | Skip them |
| Believing before and after photos | Marketing, not evidence | Look for controlled studies |
Frequently Asked Questions
What supplements should a beginner take?
Realistically, none are needed. If you want to start somewhere, creatine and vitamin D in winter are the two most defensible.
Are BCAAs useless?
For anyone eating adequate total protein, essentially yes. They may have a small role for people training fasted on very low protein intakes, which describes very few people.
Do fat burners work?
The measurable effects are very small, and mostly attributable to the caffeine content. They are not a substitute for a calorie deficit.
Should I take a multivitamin?
It is inexpensive insurance if your diet is restricted or you eat few vegetables. It is not necessary for someone eating a varied diet.
Sources
NHS vitamins and minerals guidance - https://www.nhs.uk/conditions/vitamins-and-minerals/
Examine independent supplement analysis - https://examine.com/
British Dietetic Association food facts - https://www.bda.uk.com/food-health/food-facts.html