Creatine side effects: does it cause hair loss, weight gain or bloating?

Short answer

For healthy adults taking 3–5 g a day, creatine monohydrate is one of the best-studied and safest supplements. The International Society of Sports Nutrition, after reviewing hundreds of studies, found no clinically significant or serious side effects across age groups at recommended doses (1).

What people actually notice:

• Weight gain — yes, usually 1–2 kg in the first weeks, mostly water inside muscle, not fat.

• Hair loss — the best evidence says no. A 2025 randomized trial in 45 resistance-trained men taking 5 g a day for 12 weeks found no change in DHT or in hair density, follicle count or hair thickness compared with placebo (2). The worry came from a 2009 study that measured a rise in DHT but never measured hair (3).

• Bloating and diarrhea — mostly from large single doses. In soccer players, a single 10 g dose caused diarrhea in 56%, versus 29% when the same amount was split into two 5 g doses — not different from placebo (4).

• Kidneys — no evidence of harm in healthy people, but creatine raises the blood creatinine test, which can look like a kidney problem when it isn't (5).

If you've worried that creatine might cost you your hair or your kidneys, you're not imagining a risk out of nowhere and it's not your fault — those myths are everywhere. Here's what the research actually shows.

Note: this article is for general education and is not medical advice. If you have kidney disease, diabetes, high blood pressure, liver disease, take medicines that affect the kidneys, or are under 18, talk to a doctor before taking creatine. This guide is published by Welltory, which makes one of the apps mentioned. Welltory is a general wellness product: it helps you track and understand your data and does not diagnose or treat any condition.

Does creatine make you gain weight?

Yes, but mostly water, and mostly in your muscles.

Creatine draws water into muscle cells along with it. When you start taking it — especially with a loading phase of about 20 g a day — body weight typically rises by about 1–2 kg within the first week or so. Without loading, the gain is slower and often smaller.

This isn't fat and it isn't the "puffy" water retention under the skin that people associate with salty food. It's water inside muscle cells, which is part of how creatine works. An expert review of common creatine misconceptions notes that, where observed, a water effect is short-term and temporary (5).

Over months, more weight can come from extra muscle if creatine helps you train harder. Creatine doesn't add body fat by itself; if you gain fat, look at calories rather than creatine.

Who might care: athletes in weight-class sports, runners and climbers, for whom an extra 1–2 kg matters. For most men lifting weights, it's a non-issue.

Does creatine cause hair loss?

The best current evidence says no.

Where the worry came from. In 2009, a study of 20 college rugby players found that after a week of loading with 25 g of creatine a day, blood levels of dihydrotestosterone (DHT) — the hormone involved in male pattern baldness — rose by 56% and stayed 40% above baseline after two weeks of 5 g a day. Testosterone didn't change (3). The study didn't measure hair at all, and its DHT finding hasn't been replicated in other studies (5).

What the newest trial shows. In 2025, researchers randomized 45 resistance-trained men aged 18–40 to 5 g of creatine monohydrate or placebo daily for 12 weeks. They measured DHT and hair directly, with trichograms and imaging of hair density, follicle count and thickness. There were no differences between groups in DHT, the DHT-to-testosterone ratio or any hair measure. The authors described this as the first direct assessment of hair follicle health after creatine and said it provides strong evidence against the claim that creatine causes hair loss (2).

What it means for you. If you're genetically prone to male pattern baldness, your hair may thin whether or not you take creatine. Twelve weeks is a relatively short time, so very long-term effects haven't been tested directly. If you're already losing hair and worried, talk to a dermatologist about treatments that work rather than relying on avoiding creatine.

Does creatine cause bloating or diarrhea?

Sometimes — mostly when you take too much at once.

In a study of 59 elite soccer players over 28 days (4):

• Placebo — 35%

• 2 × 5 g (split doses) — 29% — not different from placebo

• 1 × 10 g (single dose) — 56% — significantly more

How to avoid it:

• Take 3–5 g once a day, or split larger doses (such as loading) into 4–5 g portions.

• Dissolve it well in enough liquid.

• Take it with food.

• Skip the loading phase if your stomach is sensitive.

The "bloated" look some people describe in the first weeks is usually the water inside muscle described above, not gut bloating.

Is creatine bad for your kidneys?

There's no compelling evidence that creatine harms healthy kidneys at recommended doses (1). The kidney myth traces largely to misunderstandings about creatine metabolism and a single 1998 case report (5).

The creatinine catch. Creatine breaks down into creatinine, which is what standard blood tests use to estimate kidney function (eGFR). Taking creatine can raise creatinine, which can make kidney function look worse on paper (5). Tell your doctor you take creatine before blood tests; they can use another marker, such as cystatin C, if needed.

Who should be careful: people with kidney disease, diabetes or high blood pressure, and people taking medicines that can affect the kidneys — talk to a doctor before starting.

Does creatine cause dehydration or cramps?

This is a common gym myth, but studies in athletes training in heat haven't shown that creatine increases cramping, dehydration or heat illness. Drink normally, especially when training hard or in hot weather.

Does creatine cause acne?

There's no good evidence that it does. Acne in people who lift often has other explanations: sweat, friction, hormones, diet, or other products (including some pre-workouts and, at the extreme, anabolic steroids). If you get acne after starting a "creatine" product, check whether it contains other ingredients.

Is creatine a steroid?

No. Creatine is a naturally occurring compound found in meat and fish and made in your body. It isn't a hormone, doesn't act like an anabolic steroid, and isn't banned in sport.

Is creatine safe long term?

The ISSN considers creatine monohydrate safe in healthy people across ages, with daily doses of 0.3–0.8 g per kg body weight studied for several years without clinically significant adverse effects (1). The usual 3–5 g a day is far below that.

The bigger safety issue is product quality. Supplements in the US aren't approved by the FDA before sale. Choose plain creatine monohydrate with a third-party testing seal, especially if you're a tested athlete.

Creatine or the rest of the scoop? Where side effects often come from

Many "creatine side effects" are really side effects of other ingredients. Creatine is often sold inside pre-workouts, mass gainers and "stacks" that also contain:

• Caffeine and other stimulants — jitters, racing heart, poor sleep, anxiety, stomach upset;

• Beta-alanine — a harmless but strange tingling of the skin;

• Sugar alcohols and sweeteners — gas and bloating;

• Large amounts of carbohydrate in gainers — weight gain that is fat if calories exceed your needs;

• Proprietary blends — where you can't tell how much of anything you're taking.

If you get side effects, switch to plain creatine monohydrate with a single ingredient on the label. If they disappear, creatine wasn't the problem.

Who should avoid creatine or be careful?

Creatine is well tolerated by most healthy adults, but talk to a doctor first if you:

• have chronic kidney disease or a single kidney;

• have diabetes or high blood pressure, which put the kidneys at risk;

• take medicines that can affect kidney function, such as regular anti-inflammatory painkillers, some diuretics or certain blood pressure medicines;

• have liver disease;

• are under 18;

• are pregnant or breastfeeding, because research in these groups is limited;

• have bipolar disorder — a few case reports have raised questions, so discuss it with your psychiatrist.

Creatine and blood tests

If you take creatine and have routine blood work, your creatinine may come back a little high and your estimated kidney function (eGFR) a little low. That's because creatine is broken down into creatinine, the marker most labs use (5). Heavy training and a high-protein diet can push creatinine up too.

What to do:

• Tell your doctor before the test that you take creatine and train hard.

• If a result is borderline, ask whether to recheck after a few days off creatine and hard training, or to add cystatin C, a marker that isn't affected by creatine.

• Don't ignore a clearly abnormal result just because you take creatine — let your doctor interpret it.

How to choose a clean creatine product

• Pick creatine monohydrate. It's the form behind almost all the safety and effectiveness research.

• Check for a single ingredient. "Creatine monohydrate" and nothing else is ideal.

• Look for third-party testing, such as sport-certification seals, especially if you compete in tested sport.

• Prefer powder for value. Gummies and capsules cost more per gram and gummies may be harder to dose.

• Ignore "no bloat" marketing. Monohydrate taken in sensible doses rarely causes problems; claims for special forms aren't backed by strong evidence.

What happens when you stop taking creatine?

Nothing dramatic happens to your body. Over roughly four to six weeks, muscle creatine stores drift back to their usual level, and the extra water in your muscles goes with them — so expect your weight to drop by about the same 1–2 kg you gained at the start. Your body's own creatine production, which slows a little while you supplement, returns to normal.

You may notice slightly fewer reps at the same weight in hard sets, because the extra energy reserve is gone. Strength and muscle you built while taking creatine don't disappear because you stopped; they're maintained by training, like any other gains. There's no withdrawal, no "crash" and no need to taper off. If you plan to stop before a weigh-in or a race where every kilogram counts, give yourself about a month for the water weight to come off.

Creatine side effects in older adults

Interest in creatine for men over 50 has grown, because it may help preserve muscle when combined with strength training. Side effects in older adults look similar to those in younger people: mainly early water weight and occasional stomach upset. The main extra consideration is that kidney problems, high blood pressure and multiple medicines are more common with age, so a quick check with a doctor before starting is more important. Bring the product label to that appointment, along with your current list of medicines, so the check takes two minutes rather than a guess. Our guide to sarcopenia explains why muscle matters so much later in life.

Side effects at a glance

How to check whether creatine suits you

1. Note your starting point: morning weight, how your stomach feels, any skin or hair concerns.

2. Start low: 3 g a day with food, no loading.

3. Watch the first two weeks: a 1–2 kg weight rise is expected; stomach upset suggests splitting the dose or taking it with a meal.

4. Track training and recovery, not just side effects — that's how you know whether it's worth continuing. Our guide on when to take creatine and how long until it works has a 12-week plan.

Living with a supplement shelf: the questions people ask next

Can I take creatine if I'm on finasteride or worried about my hairline?

The 2025 trial found no effect of creatine on DHT or hair over 12 weeks. If you're on finasteride or other hair-loss treatment, there's no known interaction, but it's reasonable to mention creatine to your dermatologist.

Does creatine affect testosterone?

Studies, including the 2025 trial, haven't shown that creatine meaningfully changes testosterone. Our article on testosterone after 40 covers what does.

Can teenagers take creatine?

Talk to a doctor first. Most guidance focuses on adults, and young athletes usually get more from sleep, food and good coaching.

Does creatine interact with medicines?

Creatine isn't known for many interactions, but be careful with medicines that affect kidney function. Our guide to supplement and drug interactions explains how to check.

Before you blame yourself

If you gained two kilos in your first week on creatine and felt like you'd ruined your diet, you didn't. That's water in your muscles, and it's a sign creatine is doing what it's supposed to.

When to see a doctor

See a doctor if you have kidney disease, diabetes, high blood pressure or liver disease; if you take medicines that affect the kidneys; if you notice swelling, reduced urination, dark urine or unusual fatigue; or if you have ongoing stomach symptoms after splitting your dose.

How to bring this up with your doctor

What to ask for, by name. "I take creatine; could it explain a slightly high creatinine, and should we check cystatin C?"

What to bring. The product label, your dose and how long you've taken it, and recent blood results.

What to say, out loud. "I've taken [dose] of creatine monohydrate daily for [time] for strength training. Is that fine with my [condition/medicines]?"

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How Welltory helps — and what it cannot do

The limits first. Welltory is a general wellness product, not a medical device. It doesn't measure creatine, kidney function or hormones.

What it can do is show how your body handles your training while you try a new supplement.

Recovery readings. Take a morning HRV measurement with your phone camera, a compatible watch or a chest strap (camera measurements, accurate HRV measurements).

Tag what you change. When Welltory asks "What happened?", tag "started creatine", "stomach upset", "heavy session", "poor sleep" (My Patterns). Patterns start to appear after around seven tagged events; some sections need a paid plan.

A record for your doctor. From the web app you can export your data as CSV (export guide).

How we made it

We based this article on the International Society of Sports Nutrition's 2017 position stand on creatine, an expert review of common creatine misconceptions, a 2025 randomized controlled trial of creatine and hair, a 2009 study of creatine and DHT in rugby players, and a study of gastrointestinal effects of different creatine doses in soccer players. Search questions came from what people in the United States most often ask about creatine side effects. For the product section, we checked every function against the Welltory Help Center on October 23, 2026.

Made with AI tools, then edited and fact-checked by the Welltory team. See our Editorial & AI policy.

Jane Smorodnikova, co-founder of Welltory, built the methodology behind how we read physiological data.

Written by Tatsiana Yashyna.

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