The supplement industry sells about forty products for this. The evidence supports two — and one of them has a hard ceiling the industry has every reason not to mention.
Creatine monohydrate. The International Society of Sports Nutrition’s position stand describes it as the most effective ergogenic nutritional supplement currently available to athletes for increasing high-intensity exercise capacity and lean body mass during training. Monohydrate specifically is the most extensively studied and clinically effective form.
Enough protein — and there’s a number. A meta-analysis of 49 studies and 1,863 participants found protein supplementation significantly increased strength, fat-free mass and muscle size during resistance training. But gains plateaued at 1.62 g/kg/day of total protein. Beyond that, no further gains. The tub says otherwise because the tub is for sale. 💪
- Creatine: the one that genuinely works
- How to actually take it
- The kidney myth
- Protein, and the number that matters
- The 1.62 ceiling nobody advertises
- Total intake, not supplement intake
- “Getting cut” is a different problem
- Caffeine: real, with caveats
- What you’re wasting money on
- The contamination risk
- Common mistakes
- Frequently asked questions
- Your checklist
Creatine: the one that genuinely works
If you buy one supplement in your life, this is it — and unusually for this site, we can say that without hedging.
The International Society of Sports Nutrition position stand concluded that creatine monohydrate is the most effective ergogenic nutritional supplement currently available to athletes in terms of increasing high-intensity exercise capacity and lean body mass during training.
That’s not marketing language. That’s a professional body’s formal position, and it sits on top of one of the largest evidence bases of any supplement in existence.
Most of this site is spent explaining why supplements don’t do what the label says. Creatine is the exception that makes the rest of the scepticism credible.
One detail matters commercially: creatine monohydrate is the form described as most extensively studied and clinically effective for muscle uptake and increasing high-intensity exercise capacity. The exotic variants — hydrochloride, ethyl ester, buffered, “elite” blends — cost considerably more and carry a fraction of the evidence. Monohydrate is the cheapest form and the best-supported one, which almost never happens.
How to actually take it
The protocol is straightforward and the ISSN position stand states it plainly.
The quickest method of increasing muscle creatine stores is approximately 0.3 g/kg/day for 5–7 days, followed by 3–5 g/day thereafter to maintain elevated stores.
| Phase | Dose | Duration | Notes |
|---|---|---|---|
| Loading (optional) | ~0.3 g/kg/day | 5–7 days | Fastest route to saturation; split across the day |
| Maintenance | 3–5 g/day | Ongoing | This is the dose that matters long-term |
| Skip loading | 3–5 g/day from day one | Ongoing | Reaches the same place, just more slowly |
Loading is optional rather than essential — it gets you saturated faster, and some people find the higher initial dose causes stomach upset. Starting straight at maintenance arrives at the same destination over a few weeks.
Practical points: take it daily, including rest days, because you’re maintaining a store rather than timing a stimulus. Timing around workouts matters far less than consistency. And expect a small increase in scale weight early on from intracellular water — that’s the mechanism working, not fat gain.
The kidney myth
This is the objection everyone raises, and it deserves a direct answer.
The ISSN position stand addresses safety at doses far above what anyone recommends. Studies of 15–25 g/day for 4–12 weeks in athletes undergoing heavy training reported no side effects. Collegiate football players ingesting 20–25 g/day experienced greater gains in strength and muscle mass with no evidence of adverse effects.
Those are loading-level doses sustained for months — five to eight times the ordinary maintenance dose — in the population using it hardest.
Creatine raises serum creatinine, which is a marker used to estimate kidney function. Higher creatine intake means more creatinine in the blood — not because your kidneys are struggling, but because you’re consuming more of the substance it’s derived from. A routine blood test can therefore look alarming when nothing is wrong. Tell your doctor you take creatine before any kidney function test, exactly as you would with any other supplement. If you have existing kidney disease, that’s a genuine conversation to have with your doctor rather than a myth to dismiss.
Protein, and the number that matters
The second thing that works isn’t really a supplement — it’s hitting a target, and a powder is just a convenient way to do it.
The evidence here is a meta-analysis published in the British Journal of Sports Medicine, pooling 49 studies with 1,863 participants. It found that dietary protein supplementation significantly increased changes in strength, fat-free mass and muscle size during prolonged resistance exercise training.
So protein works. The interesting part is where it stops working.
The 1.62 ceiling nobody advertises
Here is the finding that should change what you buy.
Protein supplementation beyond total protein intakes of 1.62 g/kg/day resulted in no further training-induced gains in fat-free mass.
A plateau. Past roughly 1.62 grams per kilogram of bodyweight per day, additional protein produced no additional muscle. The 95% confidence interval around that breakpoint extends to about 2.2 g/kg/day, so a sensible practical reading is: aim for around 1.6, and there’s no demonstrated reason to exceed roughly 2.2.
What that means in real numbers:
| Bodyweight | Target (~1.6 g/kg) | Upper bound (~2.2 g/kg) | Beyond this |
|---|---|---|---|
| 60 kg / 132 lb | ~97 g/day | ~132 g/day | No further gains shown |
| 75 kg / 165 lb | ~122 g/day | ~165 g/day | No further gains shown |
| 90 kg / 198 lb | ~146 g/day | ~198 g/day | No further gains shown |
| 105 kg / 231 lb | ~170 g/day | ~231 g/day | No further gains shown |
Two moderating findings from the same analysis are worth knowing. The impact of protein supplementation on fat-free mass gains was reduced with increasing age, and it was more effective in resistance-trained individuals — so the people who benefit most from getting this right are the ones already training seriously.
Total intake, not supplement intake
The single most common misreading of that number: 1.62 g/kg is your total daily protein from all sources, not the amount you need from powder.
Chicken, eggs, fish, dairy, beans, tofu and bread all count. Someone eating a normal high-protein diet may already be close to the target and need very little supplementation — while someone eating little protein at meals can’t fix it with one shake.
Track your actual protein intake for three days. Not estimated — logged. Most people are surprised in one direction or the other, and until you know your baseline you can’t tell whether you need a supplement at all. If you’re already at 1.6 g/kg from food, a protein powder adds cost and nothing else. If you’re at half that, powder is a genuinely efficient fix. Three days of logging is cheaper than a year of guessing.
“Getting cut” is a different problem
The phrase bundles two goals that pull in opposite directions, and conflating them is why people spin their wheels.
Gaining muscle requires a training stimulus and adequate protein, and is easiest in a small energy surplus. Getting lean requires an energy deficit. Doing both simultaneously is possible mainly for beginners, people returning after a layoff, and those with more fat to lose — for everyone else it’s slow at best.
What actually determines whether you get lean:
- A sustained energy deficit. No supplement creates one. This is the whole mechanism.
- Enough protein — the same 1.6 g/kg target, which in a deficit does double duty by preserving lean mass and keeping you fuller.
- Resistance training, which signals your body to keep muscle while losing fat. Without it you lose both.
- Sleep, which affects appetite regulation and recovery.
- Patience. Faster deficits cost more lean mass.
Nothing in the “cutting” or “fat burner” aisle changes any of those. We’ve covered why in more detail in our review of thermogenic fat burners — including the liver-injury signal attached to one of their common ingredients.
Creatine Monohydrate
Described by the ISSN as the most effective ergogenic supplement available — and the cheapest form is the best one
This is the rare case where the evidence is strong, the dose is simple and the correct product is the inexpensive one. Buy plain monohydrate — it’s the most extensively studied and clinically effective form, and the exotic variants cost more for less evidence. Take 3–5 g daily, every day including rest days, with optional loading at ~0.3 g/kg for the first 5–7 days if you want to saturate faster. Expect a small early increase in scale weight from cell water; that’s the mechanism, not fat. Look for third-party testing, particularly if you compete in a tested sport.
- Take it daily, including rest days — you’re maintaining a store
- Monohydrate beats the expensive variants on evidence and price
- Expect a small early weight increase from intracellular water
- Choose third-party tested if you compete in a tested sport
- Tell your doctor you take it before any kidney function blood test
Caffeine: real, with caveats
Caffeine is the third thing with genuine evidence, though it belongs in a different category from the first two — it improves your training session rather than building tissue.
It reliably improves perceived effort and performance, particularly for endurance and high-volume work. The caveats are practical:
- Tolerance builds. Daily heavy use blunts the effect; it works best used deliberately rather than habitually.
- Sleep is the cost. Late-afternoon training doses can wreck sleep quality, and sleep drives recovery — so you can easily trade a better session for a worse week.
- It stacks. Pre-workout, coffee and energy drinks add up faster than people track.
- Pre-workout blends often hide doses in proprietary formulas alongside a dozen ingredients with far weaker support.
What you’re wasting money on
| Product | The claim | Reality | Verdict |
|---|---|---|---|
| BCAAs | Builds muscle, prevents breakdown | Largely redundant if you hit your protein target — whole protein already contains them, in better ratios | ❌ Skip if protein is adequate |
| “Testosterone boosters” | Raises natural testosterone | Typically herbal blends with weak or absent evidence for meaningful change in healthy men | ❌ Skip |
| Thermogenic fat burners | Burns fat | Marginal energy expenditure effects; some carry real safety concerns | ❌ Skip |
| Glutamine | Recovery, immunity | Little support for either in healthy trained people eating enough | ❌ Skip |
| Exotic creatine forms | Better absorption | Monohydrate is the most studied and effective form, and the cheapest | ❌ Buy monohydrate |
| Mass gainers | Bulk formula | Mostly sugar and maltodextrin at a premium — food does this cheaper | ⚠️ Expensive calories |
| Protein powder | Builds muscle | Works — but only to the extent it gets you to ~1.6 g/kg total. Not magic, just convenient | ✅ If you’re short on protein |
The contamination risk
Worth flagging specifically for anyone who competes, and worth knowing for everyone else.
Sports supplements are a category where undeclared ingredients have repeatedly been found — including substances banned in tested sport. For an athlete subject to drug testing, “I didn’t know it was in there” is generally not a defence, and a contaminated pre-workout can end a career.
- Choose third-party tested products — Informed Sport, NSF Certified for Sport, or equivalent.
- Be most careful with pre-workouts and “proprietary blends”, where undisclosed amounts make verification impossible.
- Search the product name plus “FDA tainted products” before buying.
- Simple, single-ingredient products like plain creatine monohydrate carry less risk than complex blends by their nature.
Common mistakes
- Buying protein powder without knowing your intake. You may already be at target. Fix: log three days first.
- Chasing protein far beyond 1.62 g/kg. Gains plateaued there. Fix: hit the target, then stop spending.
- Buying exotic creatine. Monohydrate is best-studied and cheapest. Fix: buy the plain one.
- Skipping creatine on rest days. You’re maintaining a store. Fix: daily.
- Panicking at early weight gain on creatine. It’s cell water. Fix: expect it.
- Trying to cut and bulk simultaneously. They pull opposite ways. Fix: pick one for a block.
- Buying a fat burner instead of running a deficit. Fix: the deficit is the mechanism.
- Not mentioning creatine before a kidney blood test. Fix: tell them; it raises creatinine legitimately.
Frequently asked questions
What’s the single best supplement for building muscle?
Creatine monohydrate. The International Society of Sports Nutrition’s position stand describes it as the most effective ergogenic nutritional supplement currently available to athletes for increasing high-intensity exercise capacity and lean body mass during training. Monohydrate specifically is the most extensively studied and clinically effective form — and it’s the cheapest, which is unusual. Take 3–5 g daily, every day, with optional loading of about 0.3 g/kg for the first 5–7 days.
How much protein do I actually need?
A meta-analysis of 49 studies and 1,863 participants found gains plateaued at a total protein intake of 1.62 g/kg/day — beyond that, protein supplementation produced no further training-induced gains in fat-free mass. The confidence interval extends to about 2.2 g/kg/day, so aiming for roughly 1.6 and not exceeding around 2.2 is a sensible reading. Crucially, that’s total protein from all food and drink, not the amount you need from powder.
Is creatine bad for your kidneys?
The evidence doesn’t support that concern in healthy people. The ISSN position stand cites studies at 15–25 g/day for 4–12 weeks in athletes in heavy training with no reported side effects, and collegiate footballers at 20–25 g/day gaining strength and muscle with no evidence of adverse effects — doses far above the usual 3–5 g. The myth persists because creatine raises serum creatinine, a marker used to estimate kidney function, so tests can look alarming when nothing is wrong. Tell your doctor you take it before kidney testing, and discuss it properly if you have existing kidney disease.
Do I need BCAAs?
Almost certainly not if you’re hitting your protein target. Whole protein sources already contain branched-chain amino acids, in complete ratios alongside everything else you need. BCAAs are essentially a partial, more expensive version of something you’re already consuming. The money is better spent on getting total protein to around 1.6 g/kg, or on creatine.
Can I build muscle and lose fat at the same time?
To a degree, and mainly if you’re a beginner, returning after a break, or carrying more body fat. For most trained people the two goals conflict — building muscle is easiest in a small surplus, losing fat requires a deficit. The practical approach is to pick one focus for a block of time. In a deficit, keep protein at target and keep resistance training, because that’s what preserves lean mass while you lose fat; without it you lose both.
Are pre-workouts worth it?
The caffeine in them does something real — improved perceived effort and performance. The rest of a typical pre-workout is a long ingredient list with much weaker support, often in a proprietary blend that hides doses. Plain caffeine at a known amount gives you the effect you’re paying for, more cheaply and more predictably. Watch total intake across coffee and energy drinks, avoid late-afternoon doses that damage sleep, and be aware pre-workouts are the category where contamination risk is highest — choose third-party tested if you compete.
Your checklist
- Log three days of protein before buying any powder
- Aim for around 1.6 g/kg/day total; no demonstrated reason past ~2.2
- Remember that’s all sources, not supplement alone
- Buy plain creatine monohydrate, not the exotic forms
- Take 3–5 g daily, including rest days
- Expect a small early weight increase from cell water
- Tell your doctor about creatine before kidney function tests
- Pick one goal per block — cutting or building
- Keep resistance training during a deficit to protect lean mass
- Choose third-party tested products if you compete
- Search products for “FDA tainted products” before buying
Affiliate disclosure. Some links on this page are affiliate links. As an Amazon Associate we earn from qualifying purchases. This never affects our conclusions — this article recommends the cheapest form of the one supplement it endorses, and advises against most of the category.
