Creatine, Explained: What It Actually Does and Whether You Should Take It

If you've spent any time around a gym, a supplement aisle, or fitness content online, you've heard the word "creatine." It's one of the most talked-about supplements in fitness, and also one of the most misunderstood. Some people swear by it, others worry it'll wreck their kidneys or cause bloating and hair loss. So what's actually true?

Here's a clear, no-hype look at what creatine is, what it does, and what the current research actually says.

What Creatine Actually Is

Creatine is a naturally occurring compound made in your liver, kidneys, and pancreas, and it's also found in foods like red meat and fish. Your body stores most of it in skeletal muscle, where it helps regenerate ATP (the molecule your muscles use for quick, explosive energy). That's why creatine's biggest, best-documented benefit is improved performance in short, high-intensity efforts: heavy lifts, sprints, jumps, and other power-based movements.

Supplementing with creatine simply tops up what your muscles can already store, giving you a bit more fuel for that kind of output.

What the Research Actually Shows

According to the International Society of Sports Nutrition (ISSN), which has reviewed decades of research on the topic, creatine monohydrate is considered the most effective supplement currently available for increasing high-intensity exercise capacity and building lean muscle mass during training. Beyond the gym, ongoing research also points to potential benefits for recovery, injury prevention, and even brain health and aging, though those areas are still developing compared to the well-established performance benefits.

In plain terms: if your goal is strength, power, or muscle growth, creatine has one of the strongest evidence bases of any supplement on the market.

Is It Safe?

This is where most of the hesitation comes from, so let's address it directly.

Kidney damage. This is the most persistent myth. Large-scale research, including a 2025 meta-analysis covering hundreds of trials, has found no evidence that creatine harms kidney function in healthy people at recommended doses (3–5 grams per day). Creatine can cause a small, harmless bump in serum creatinine, a common blood marker doctors use to estimate kidney function, but this doesn't reflect actual kidney damage. The ISSN's own position stand notes that even doses as high as 30 grams per day have been used safely for up to five years in monitored settings.

Hair loss. This myth traces back to a single small study from 2009 that showed a hormonal change, not actual hair loss. A more recent randomised, placebo-controlled trial that directly measured hair follicle health found no meaningful difference between creatine users and a placebo group. There's currently no solid evidence linking creatine to hair loss.

Bloating. This one has some truth to it, but it's misunderstood. Any water retention from creatine happens inside the muscle cells, not under the skin, it's part of why muscles can look fuller, not puffier. It's also typically temporary and most noticeable during a "loading phase," if you choose to do one.

Overall. A 2025 meta-analysis found that reported side effects with creatine occur at almost the same rate as with a placebo (about 4.6% versus 4.2%), which is about as reassuring as safety data gets for a supplement.

How to Actually Take It

You don't need to overcomplicate this:

A daily dose of 3–5 grams of creatine monohydrate is the standard, well-researched amount. You can take it any time of day, with or without food, consistency matters more than timing. Some people choose a "loading phase" (around 20 grams per day, split into smaller doses, for 5–7 days) to saturate muscle stores faster, but it's optional. Skipping it just means it takes a couple of extra weeks to reach the same saturation point.

Creatine monohydrate specifically is the form with by far the most research behind it. Fancier or "advanced" versions on the market haven't shown any clear advantage, so there's rarely a reason to pay more for them.

Who Should Think Twice

Creatine is well-studied in healthy adults, but if you have pre-existing kidney disease, are pregnant or breastfeeding, or are on medications that affect kidney function, it's worth talking to a doctor before adding any new supplement, creatine included. This is general information, not personalized medical advice.

The Bottom Line

Creatine monohydrate is cheap, extensively studied, and backed by one of the strongest safety and efficacy profiles of any supplement available. The myths about kidneys, hair, and bloating don't hold up well against the current evidence. If your training involves strength, power, or muscle-building goals, it's one of the few supplements genuinely worth considering.

Sources:

• International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine — Journal of the ISSN
• Creatine Reconsidered: What the Latest Research Reveals — ACE Fitness
• Does Creatine Cause Hair Loss? — Cleveland Clinic
• Debunking Creatine Myths — Transparent Labs