Creatine and Protein Powder: What the Evidence Says

Walk down a supplement aisle and you could believe getting fit requires a small chemistry set: pre-workouts, BCAAs, fat burners, mass gainers, a tub for every goal. Strip away the marketing and the research tells a much simpler story. Of everything on that shelf, only two supplements have a genuinely strong, repeated evidence base behind them. Everything else ranges from mildly useful to a waste of money.

Creatine: the most studied supplement in sports science

Creatine monohydrate has been researched for more than three decades, in thousands of people, and the conclusions have held up remarkably well. The International Society of Sports Nutrition’s position is about as close to settled science as sports nutrition gets: creatine is the most effective supplement currently available for increasing high-intensity exercise capacity and lean body mass when paired with training, and it’s safe for healthy adults at recommended doses, including over long-term use.

What it actually does is unglamorous but useful. Creatine tops up your muscles’ short-term energy stores, which lets you squeeze out an extra rep or two, or recover a little faster between sets. Over months of consistent training, that small edge compounds into a meaningful difference in strength and muscle gained.

The dose that matters is 3 to 5 grams a day, taken consistently — there’s no need for the old-fashioned loading phase of 20 grams a day unless you’re in a hurry to saturate your muscles for a specific event. Timing doesn’t matter much either; taking it with a meal, any time of day, works fine.

The most common side effect is a small amount of water retention in the muscle, which shows up as a bit of extra weight on the scale rather than fat. It isn’t dangerous, but it catches people off guard if they don’t expect it. For healthy adults, the research doesn’t support concerns about kidney damage at standard doses. If you have existing kidney disease, or you’re not sure, that’s a conversation for your doctor before you start, not a reason to assume the worst from general research on healthy populations.

Protein powder: convenience, not magic

We’ve covered this in more depth when talking about eating for muscle gain, so briefly: protein powder isn’t necessary if whole food gets you to your target, but it’s a legitimate, well-evidenced way to close the gap when it doesn’t. Whey is absorbed quickly, which suits a post-workout shake, but the type matters far less than hitting your daily total. Plant-based blends (pea, soy, rice) perform comparably once you’re getting a mix of amino acids across the day.

If you’re choosing a product, look for one that’s been third-party tested for banned substances and contaminants, and don’t pay extra for elaborate blends promising “muscle-building matrices.” A simple, tested whey or plant protein does the job.

Where the rest of the shelf falls short

Pre-workout supplements mostly work because of the caffeine in them, at a dose you could get from a strong coffee for a fraction of the price. BCAAs (branched-chain amino acids) add little on top of a diet that already hits its total protein target, which most of the research now shows is the part that actually matters. Fat burners have a long history of overpromising and underdelivering, and the ingredients with any real effect are usually just caffeine again, in a more expensive bottle.

None of this means these products are dangerous, just that the evidence for them doesn’t come close to what backs creatine and protein. If a shortlist has to exist, it’s short: creatine, protein (from food or powder), and otherwise, your money is generally better spent on food, sleep, or a few sessions with a coach.

The honest summary

Supplements were never going to replace the training itself, and the two that survive genuine scrutiny are the least exciting ones in the shop. Creatine and protein won’t transform a poor programme, but stacked on top of consistent training, sensible eating and enough sleep, they’re a small, well-earned edge worth having.