Is Creatine Safe? What 685 Clinical Trials Show

When I was running my supplement store in Miami, creatine was the one product where customers actually came back to tell me it worked. Not “I think something is happening” — but “I added 25 pounds to my bench press in five weeks” or “I’m recovering faster between sets, what is this stuff?”

That doesn’t happen with most supplements. A lot of what’s on the shelf produces results that are impossible to separate from placebo, wishful thinking, or just eating better that week. Creatine is different. You feel it. You measure it. The numbers go up.

After many years behind that counter, and after going through the research myself, here’s everything you actually need to know — without the hype, the scare stories, or the bro-science.

What Is Creatine?

Creatine is a compound your body already makes — about 1 gram per day — produced in your liver, kidneys, and pancreas. You also get small amounts from eating meat and fish. Around 95% of the creatine in your body is stored in your muscles, where it helps regenerate ATP — the fuel your cells burn during short, explosive efforts like lifting, sprinting, or any high-intensity work.

When you supplement with creatine, you’re topping off those muscle stores beyond what diet and your body alone can provide. More stored creatine means more available energy during the moments that count — the last two reps, the final sprint, the set you would have cut short.

That’s it. No mystery. No magic. Just more fuel where your muscles need it most.

What Does the Research Actually Show?

Here’s where creatine separates itself from almost every other supplement on the market. This isn’t a compound with two studies and a lot of marketing. We’re talking about hundreds of peer-reviewed studies across decades of research (a 2025 safety analysis alone pooled 685 human clinical trials), covering everyone from elite athletes to elderly populations to people with neurological conditions.

That last point surprises a lot of people. The brain uses around 20% of your body’s energy despite being only 2% of your body weight. Creatine’s role in ATP regeneration doesn’t stop at the muscles — and researchers are actively studying what that means for mental performance, aging, and neurological conditions.

The 2017 International Society of Sports Nutrition position paper — which reviewed the entire body of research — concluded that creatine monohydrate is the most effective ergogenic nutritional supplement currently available for increasing high-intensity exercise capacity and lean body mass.

That’s not a supplement company saying that. That’s the research community.

Who Should Take Creatine?

The honest answer is: more people than you’d think.

The gym crowd already knows about creatine. But based on current research, these groups also stand to benefit significantly:

• Strength and power athletes — This is the core use case. If you lift weights, sprint, play basketball, football, soccer, or do any sport with explosive demands, creatine has a direct, measurable impact on your performance.
• Older adults — One of the most underappreciated use cases. Muscle loss accelerates after 50, and creatine has shown real promise for slowing that decline, supporting strength, and even reducing fall risk when combined with resistance training. I wish more people over 60 knew about this.
• Vegetarians and vegans — Because creatine comes primarily from meat and fish, people who don’t eat animal products tend to have lower baseline muscle creatine stores. Supplementation has shown particularly strong effects in this group. If you’re plant-based and training, this one is almost a no-brainer.
• People dealing with mental fatigue or high stress — Early research here is promising. Creatine supplementation has shown improvements in cognitive tasks, particularly under conditions of sleep deprivation or mental exhaustion. This is still an emerging area but worth watching.

How Much Should You Take?

I’ll make this simple because people overcomplicate it constantly.

A loading phase (20g/day for 5–7 days) can help you reach saturation faster, but it’s not necessary for long-term results.

Timing doesn’t matter much. Before training, after training, with food, without food — the research shows consistency matters far more than timing. Take it at the same time every day so you don’t forget.

Is Creatine Safe?

I’m going to be direct here: yes, creatine is safe for healthy individuals, and the fear around it has never matched the evidence.

Every concern I heard from customers in the store — kidney damage, liver stress, hair loss, dehydration, cramping — has either been debunked in research or was based on a single poorly-designed study from decades ago that has never been replicated.

Long-term studies following people taking creatine for years have found no adverse effects in healthy individuals. The ISSN, the American College of Sports Medicine, and essentially every major sports science body have affirmed this.

The biggest look at this so far is a 2025 analysis of 685 human clinical trials, with 12,839 people taking creatine and 13,452 taking a placebo, in studies lasting as long as 14 years. Side effects were reported by 4.6% of people taking creatine and 4.2% of people taking placebo, a difference that wasn’t statistically significant, and that included markers of kidney function. (In the interest of transparency: some of the authors disclosed ties to the creatine industry.)

The kidney myth deserves a special mention. Creatine does raise creatinine levels in your blood — creatinine is a metabolic byproduct that doctors use to assess kidney function. Some early studies saw this and raised concerns. But raised creatinine from creatine supplementation is a normal metabolic response, not a sign of kidney damage. Actual kidney function markers — like GFR — remain normal. If you have healthy kidneys, creatine is not a threat to them.

If you have a pre-existing kidney condition, talk to your doctor first. That’s genuinely good advice, not a legal disclaimer.

Common Myths — Let’s Put These to Rest

Which Type of Creatine Should You Buy?

Walk into any supplement store and you’ll see a dozen forms — creatine HCl, creatine ethyl ester, buffered creatine, creatine nitrate, and more. Most of them cost significantly more than creatine monohydrate.

Save your money. Creatine monohydrate is the form used in the vast majority of research. It’s the cheapest, the most studied, and has never been shown to be inferior to any other form in a properly controlled study. The other forms are largely a marketing exercise.

Buy creatine monohydrate. Look for products that are Creapure certified — that’s a quality mark for pharmaceutical-grade creatine produced in Germany. It’s flavorless, mixes easily, and works exactly as advertised.

Here’s how the most common forms compare in controlled trials. For prices per gram of actual creatine from real brands, see our full creatine guide.

Final Thoughts

I’ve watched a lot of supplement trends come and go. Products that were everywhere one year and completely forgotten the next. Ingredients that were “clinically proven” until you looked at who funded the study.

Creatine is not a trend. It was one of the top sellers in my store and it’s been one of the most consistently validated compounds in sports science for over three decades. The research has only gotten stronger over time, not weaker — which is the opposite of what happens with most supplement ingredients.

If someone walked into my store today and asked where to start, I’d say the same thing I said a hundred times behind that counter: start with creatine. Get the basics right. Everything else builds from there.

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