Creatine and Magnesium Myths, Checked Against the Evidence

Creatine and magnesium are two of the best-studied supplements you can buy, and two of the most argued about. Here's every common claim we hear, checked against the research. The verdict says whether the claim holds up; the grade says how strong the evidence behind that verdict is.

Grades work the same way across the site: Good means several controlled trials agree, Mixed means they point in different directions, Early means one or two small trials, and Weak means little support at all. More on how we grade.

Creatine myths at a glance

Creatine, claim by claim

"Creatine is a steroid"

FalseGood evidence

Creatine is built from three amino acids, your body makes about half of what it uses each day, and it's in every steak and salmon fillet. It doesn't act like a hormone and isn't on any anti-doping banned list. A review of twelve studies found ten showed no change in testosterone, and the other two found small changes within the normal range. More in what creatine is.

"Creatine damages your kidneys"

False, for healthy peopleGood evidence

This one comes from a blood test. Creatine breaks down into creatinine, and doctors use creatinine to estimate kidney function. Taking creatine raises it a little, which can make healthy kidneys look like they're struggling. Studies that measured kidney function directly, for up to five years, found no harm in healthy people (Kreider et al., 2017). If you already have kidney disease, the picture is different: ask your doctor first. Details in is creatine safe?

"Creatine dehydrates you and causes cramps"

FalseGood evidence

Researchers who reviewed the evidence found no support for this. Several studies of athletes training in the heat found creatine users had the same or fewer cramps and injuries than those who didn't take it. You don't need to drink extra water because you take it.

"Creatine causes hair loss"

No evidence it doesEarly evidence

The idea traces back to a single 2009 study of 20 rugby players that found a rise in a hormone called DHT. It never measured hair. In 2025, a 12-week trial gave 45 men 5 g a day and checked their hair directly: no difference from placebo. That's one trial, in men only, so the grade is Early. But the evidence that started the worry didn't measure hair at all.

"Creatine makes women bulky"

FalseGood evidence

Creatine helps you train a little harder, and muscle comes from training plus food. It doesn't add fat, and the water it pulls into muscle is small. In one trial, 12 women took 20 g a day for five days with no significant change in body weight. Women start with lower creatine stores than men, which is one reason researchers think it may be worth more to them, not less. See creatine for women.

"Creatine makes you gain weight"

True, but it's waterGood evidence

Many people gain 0.5 to 2 kg (1 to 4 lb) on the scale in the first few weeks, mostly with a loading phase. It's water held inside muscle cells, not fat, and it stops rising after a month. Skipping the loading phase keeps it small. See creatine bloating and water weight.

"You need a loading phase"

FalseGood evidence

Loading (about 20 g a day for 5 to 7 days) fills your muscles in a week. Taking 3 to 5 g a day from the start gets you to exactly the same place in about four weeks (Kreider et al., 2017). Loading is optional, and it's harder on the stomach. Our creatine calculator works out both plans for your bodyweight.

"You need to cycle off creatine"

FalseGood evidence

There's no sign your body stops responding over time. Studies have followed people taking it daily for up to five years. If you stop, your muscle stores drift back to normal over four to six weeks, and that's all that happens.

"HCl and other new forms work better"

FalseGood evidence

Creatine HCl dissolves far better in water, which is real. But in head-to-head trials, including an 8-week trial in elite athletes, it worked no better than monohydrate. HCl also contains less creatine per gram, and it usually costs two to three times as much. The same goes for buffered creatine and the various blends. See the best form of creatine.

"Women's creatine is different"

FalseGood evidence

Check the Supplement Facts panel on a creatine sold for women and you'll usually find creatine monohydrate, the same as the standard tub, sometimes with a flavor or a small dose of something extra. There's no women's form of creatine in the research; the trials in women used plain monohydrate. Our best creatine for women guide compares the options on price per 5 g.

"Creatine works even if you don't train"

Mostly falseWeak evidence

Creatine's main job is helping you squeeze out a little more work in hard, short efforts. Without training, there's little for it to add to: studies of creatine on its own show little effect on muscle or bone. Its effects on the brain are a separate, early area of research.

"Coffee cancels out creatine"

Probably falseMixed evidence

Some early research suggested caffeine might blunt creatine's effect. Later studies haven't backed that up in any meaningful way, though the research isn't fully settled. Taking your creatine in your morning coffee is fine, and the warmth helps it dissolve.

Magnesium myths at a glance

Magnesium, claim by claim

"All forms of magnesium are the same"

FalseGood evidence

They differ in two ways that matter: how much is absorbed, and what they do to your gut. Organic forms like citrate and glycinate absorb better than oxide, and in one well-known study only about 4% of oxide was absorbed. Citrate works as a mild laxative; glycinate rarely does. See magnesium glycinate vs citrate and the other forms.

"The big number on the front is your dose"

Usually falseGood evidence

"Magnesium Glycinate 1,000 mg" on the front of a bottle usually means the weight of the whole compound. Only about 14% of that is magnesium, so you'd be getting about 140 mg. The Supplement Facts panel on the back lists the real figure. Our magnesium label checker converts any form for you.

"Magnesium glycinate cures insomnia"

OverstatedEarly evidence

The best trial gave 155 adults with poor sleep 250 mg of magnesium as bisglycinate or a placebo for four weeks. Magnesium won, but by a small margin, and most people were still in the mild-insomnia range at the end (2025 trial). It can help a little. It isn't a sleeping pill. The full breakdown is in magnesium glycinate for sleep.

"More magnesium is better"

FalseGood evidence

The NIH sets the upper limit for magnesium from supplements at 350 mg a day for adults (NIH ODS). Above that, diarrhea and cramping become more likely, and people with kidney disease can build up dangerous levels. Most trials used 200 to 350 mg.

"Most people don't get enough magnesium"

Partly trueGood evidence

According to the NIH, many people in the US get less magnesium from their diet than the recommended amount: 310 to 320 mg a day for women and 400 to 420 mg for men (NIH ODS). But eating less than the target isn't the same as being deficient. Symptoms of true deficiency are uncommon in healthy people, because the kidneys hold on to magnesium when intake is low.

"Magnesium fixes anxiety"

Not provenWeak evidence

You'll see this claim on a lot of labels and social media posts. There's little direct trial evidence for it, and almost none for glycinate specifically. If anxiety is affecting your life, a doctor can help in ways a supplement can't.

"Magnesium stops muscle cramps"

UnclearMixed evidence

Studies of magnesium and ordinary muscle cramps have been inconsistent. Some people swear by it; controlled trials haven't shown a reliable effect. It's cheap and low risk to try at normal doses, but don't expect a sure fix.

"Glycinate absorbs far better than citrate"

Not provenMixed evidence

Both are well-absorbed organic forms, and reviews don't show a clear winner between them. Glycinate's real advantage is that it's gentler on the stomach. Citrate's is that it's cheaper and helps with constipation. See glycinate vs citrate.

Spotted a myth we've missed?

Email hello@labelliterate.com with the claim and, if you have it, where you saw it. We add new claims when a reader sends one in and the research is there to check it against.

Questions people ask

Is creatine bad for you?

Not for healthy adults at 3 to 5 g a day. Trials have run for up to five years without safety problems. People with kidney or liver disease, and anyone pregnant, should check with a doctor first.

Does creatine cause baldness?

There's no evidence it does. The worry comes from a 2009 study that measured a hormone, not hair. A 2025 trial that measured hair directly found no difference from placebo.

Does magnesium really help you sleep?

A little, for some people. The best trial found a small improvement in insomnia symptoms over four weeks with 250 mg a day. It isn't a sleeping pill.

TD

Written by Tom D

Tom has trained in the gym for years and has taken 5 g of creatine every day for about a decade, with magnesium on and off for most of the year. Reading the research behind supplements started as a hobby; this site is where he writes it up. He isn't a doctor or dietitian, so every claim links to the study behind it.

Sources

1. Kreider et al. 2017, ISSN position stand on creatine safety and efficacy (JISSN)
2. Antonio et al. 2021, Common questions and misconceptions about creatine (JISSN)
3. 2025 randomized trial of creatine and hair (summary)
4. Creatine monohydrate vs HCl in elite athletes, JISSN 2025
5. NIH Office of Dietary Supplements, Magnesium fact sheet
6. Firoz & Graber 2001, Bioavailability of US commercial magnesium preparations
7. Magnesium bisglycinate and sleep, randomized trial (2025)

We link to the original study wherever we can. Read how we grade evidence and choose products.