The supplement industry is full of promises. But only a few are actually backed by quality research. Here's exactly what works, what helps at the margins, and what's a waste of money.
Before buying supplements — know your calorie and protein targets. Calculate them here.
Open the free nutrition engine →The essentials (they really work)
Protein powder — not 'magic', but the easy way to hit your daily protein target, which is the foundation for building muscle. Creatine monohydrate — the most proven supplement for strength and mass, 3-5 g/day. These are the only two supplements most lifters actually need.
The useful (help at the margins)
Casein — slow-digesting protein, good before bed. Pre-workout / caffeine — improves performance in hard sessions. Vitamin D and Omega 3 — don't 'build muscle' directly but support overall health and recovery.
The overrated
BCAAs (redundant if you eat enough protein), 'testosterone boosters', and expensive mass gainers (mostly sugar — cheaper to just eat food). Don't waste money on these.
How to build a smart stack
Start with the base: protein + creatine. Add caffeine before hard workouts if needed. Cover vitamin D and omega 3 for general health. That's it — you don't need more. The money saved is better spent on quality food.
What works, what it costs, and how strong the evidence is
Everything below in one view. "Evidence" means how consistently controlled trials find a real effect on muscle or performance — not how loudly it is marketed. Cost is a rough per-serving figure for mid-range products, to show relative value rather than exact prices.
| Supplement | Typical dose | Evidence | Cost / serving | What it actually does |
|---|---|---|---|---|
| Creatine monohydrate | 3–5 g daily, any time | Strong | ~$0.10 | Strength and lean mass. The most studied sports supplement there is. |
| Protein powder | 20–40 g per serving, to fill your daily gap | Strong | ~$1.00 | Not magic — a convenient way to reach a protein target you were missing. |
| Caffeine | 3–6 mg per kg, 30–60 min pre-training | Strong | ~$0.15 | Measurably better output in hard sessions. Tolerance builds. |
| Beta-alanine | 3–6 g daily, split | Moderate | ~$0.20 | Helps in 1–4 minute efforts. Causes harmless skin tingling. |
| Citrulline malate | 6–8 g pre-training | Moderate | ~$0.30 | Small endurance benefit in high-rep work. |
| Casein | 20–40 g, usually before bed | Moderate | ~$1.20 | Slow-digesting. Useful mainly as convenience, not a separate effect. |
| Vitamin D / Omega 3 | as advised for your own levels | Indirect | ~$0.15 | General health and recovery. Not muscle-building on their own. |
| BCAAs | — | Weak | ~$0.60 | Redundant once daily protein is adequate. Skip. |
| Testosterone boosters | — | Weak | $1.00+ | No consistent effect in healthy men. Skip. |
| Mass gainers | — | Weak | ~$2.00 | Mostly sugar and milk powder. Cheaper to eat food. |
Three of the ten are worth most people's money. That ratio is the honest summary of this industry.
How to choose the product — what to check on the label
Creatine: buy monohydrate. HCl, ethyl ester and "buffered" versions cost more and have never beaten it in a head-to-head trial. Look for a single-ingredient tub and a third-party testing mark (Informed Sport or NSF). Flavourless powder is the cheapest form of the same thing.
Protein powder: divide grams of protein per serving by the serving size. Anything under roughly 70% is padded with filler. Check the protein figure against the scoop size, not the tub size, since "servings per container" is where the marketing hides. Whey concentrate is fine for most people; isolate is worth the premium only if lactose bothers you.
Pre-workout: ignore the blend name and read the caffeine dose per scoop. Proprietary blends that do not disclose amounts are impossible to compare, and plain caffeine plus creatine gets you most of the effect for a fraction of the price.
Anything: a long ingredient list is a warning, not a feature. Products worth buying have few ingredients in disclosed amounts.
When to take them
Timing matters far less than most marketing implies. Creatine works through saturation, so the time of day is irrelevant — only taking it every day is. Protein matters as a daily total; spreading it across three or four meals is slightly better than one large hit, but the "anabolic window" after training turns out to be hours wide, not minutes. Caffeine is the one real exception: it needs 30–60 minutes to peak, and taken late it will cost you sleep, which undoes more than the session gained.
Side effects worth knowing
Creatine causes a small increase in water held inside muscle — typically one to two kilograms in the first weeks. This is regularly misread as fat gain and it is not; it is also the reason the scale moves before anything else does. Decades of study have found no kidney harm in healthy people. Beta-alanine causes a tingling sensation that is harmless and dose-dependent. High-dose caffeine brings the obvious costs: poor sleep, jitters, a rising tolerance. Protein powder is food, and the usual limits of any dairy or plant intolerance apply.
Two stacks, by experience
Starting out: creatine monohydrate, 5 g daily, and protein powder only on the days you fall short of your target. That is the whole list. It costs a few dollars a week and covers the overwhelming majority of the available benefit.
Training seriously for a few years: the same base, plus caffeine before hard sessions, and optionally beta-alanine if your training features sustained one-to-four-minute efforts. Everything beyond that is refinement measured in fractions of a percent, and only worth buying once sleep, calories and daily protein are genuinely consistent.
🛒 Recommended for this guide
🥤Whey ProteinCheck price →💪Creatine MonohydrateCheck price →🌙CaseinCheck price →⚡Pre-workoutCheck price →Buying from the US or UK? Our home fitness gear page lists the same supplements on Amazon, alongside equipment. The links above search AliExpress, which ships more widely.
FAQ
What's the most important supplement?
If you pick one — protein powder (to complete your protein). If two — add creatine.
Are BCAAs worth it?
Usually not. If you hit your daily protein target, BCAAs are redundant.
Do I need a mass gainer?
No. Gainers are mostly expensive sugar — better to add calories from real food.
What are the best supplements for muscle gain?
Creatine monohydrate and protein powder. Those two carry most of the evidence and most of the benefit; caffeine helps performance in hard sessions. Everything else in the category is either marginal or unsupported.
How long before supplements show results?
Creatine changes measurable strength within two to four weeks, and puts one to two kilograms of water into muscle before that. Protein powder has no effect of its own — it works only insofar as it closes a gap in your daily protein, so the timeline is the timeline of your training.
Is creatine safe?
In healthy adults it is one of the most studied supplements available and has not been shown to harm the kidneys. The common complaint is water weight in the first weeks, which is inside the muscle rather than fat. Anyone with existing kidney disease should ask a doctor first.
Do I need supplements to build muscle at all?
No. Training, total calories and total protein account for nearly all of the result. Supplements are a convenience and a small edge at the margin — which is why the money is better spent on food if you have to choose.