Creatine: who it actually helps, how much to take, and when to ask your doctor

Creatine is everywhere right now. It looks at you from shop shelves, from your feed, from conversations with friends: "just try it, it's the most researched supplement in the world." Five years ago it belonged to the world of weightlifting — today it's sold to women over 40 as a remedy for fatigue, brain fog, muscle loss and even fragile bones.

And there you are, holding the tub, wondering: does this actually work — or is it simply a new wave of marketing?

I spent more time on this article than on anything else I've written for the blog. Not because the topic is complicated, but because it's surrounded by beautiful numbers that fall apart when you check them. So today, an honest conversation: what creatine really does, what it doesn't do, who it isn't for, and how to take it properly. Without the hype — and without the scare stories. 🌱

What creatine actually is

Let's start simply. Creatine is not a hormone, not a stimulant, and not "sports chemistry". It's a substance your body makes on its own — roughly a gram a day — and that you also get from food, mainly meat and fish.

Its job is to be a fast energy reserve. When a cell needs energy right now (a short effort, lifting something, a sprint, the first seconds of a set), it spends a molecule of ATP. Creatine helps restore it almost instantly — like a small power bank keeping the cell going until slower energy systems come online.

So the logic is simple: a bigger reserve means more work in short, intense moments. Everything else follows from that single mechanism. And that's exactly why so many loud promises about creatine don't survive scrutiny: they reach far beyond what this mechanism can deliver.

What creatine really does

Here's the good news. What is confirmed is confirmed very solidly: creatine has been studied for decades, across hundreds of trials.

1. It helps you gain lean mass — but only alongside resistance training. In a pooled analysis of 61 controlled trials (1,457 participants), creatine produced +1.39 kg of fat-free mass compared with placebo (Ashtary-Larky et al., JISSN, 2025). In another analysis — 143 trials — body mass rose by +0.86 kg while body fat fell by 0.28 percentage points (Pashayee-Khamene et al., JISSN, 2024).

An honest caveat you'll rarely hear in an advert: part of that weight is water inside the muscle cells, not protein alone. And most of these trials were done in men.

2. It adds a little strength in the main lifts. 69 randomised trials, 1,937 participants: bench press +1.43 kg, squat +5.64 kg versus placebo. Leg press and grip strength, however, did not change significantly (Kazeminasab et al., Nutrients, 2025).

A kilo and a half on the bench is one small plate. Not a revolution. But over several months, those "small plates" add up to a difference you can feel.

3. It helps with repeated short efforts. Average power across a series of sprints rises noticeably — while peak power and resistance to fatigue do not (Glaister & Rhodes, IJSNEM, 2022). In other words, creatine helps you repeat an effort rather than make a single effort stronger.

4. For postmenopausal women it gives a small but real gain. A meta-analysis of 7 trials, 608 women, average age around 62: +0.37 kg lean mass and +7.5 kg on the leg press — but only at 5 g a day or more and always together with resistance training (Naddafha et al., JISSN, 2026).

Here I want to be completely honest: the confidence interval in that analysis crosses zero. In plain terms — some women will get no effect at all, and that is a normal, expected outcome, not your fault.

The one thing to remember, if you remember nothing else: creatine is an amplifier of your training response. It makes your work a little more productive. It does not do the work for you.

What creatine does NOT do

I consider this the most important part. Because this is exactly where marketing outruns the science — and these are the promises that make women buy the supplement and then feel let down.

It does not build muscle without training. Across 35 trials the gain was around +1.10 kg with resistance training — and essentially disappeared without it (Delpino et al., Nutrition, 2022). More than that: creatine does not increase the rate of muscle protein synthesis directly. Its effect on muscle size is indirect.

It does not strengthen bone. This is probably the most widespread myth in conversations about women over 50. The data say the opposite: a meta-analysis of 5 trials found no effect on bone density at all (Forbes, Chilibeck & Candow, Front Nutr, 2018). And crucially — a two-year trial in 237 postmenopausal women, with resistance training three times a week, found no difference in bone density at the femoral neck, the hip or the spine (Chilibeck et al., MSSE, 2023). Both groups got noticeably stronger. Both groups still lost bone.

It is not proven for memory or "mental clarity". In November 2024 the European Food Safety Authority (EFSA) reviewed 23 studies and formally refused permission to claim that creatine improves cognitive function: a cause-and-effect relationship has not been established. The memory meta-analysis was later corrected by its own authors — the overall effect fell to statistically non-significant (Prokopidis et al., Nutr Rev, 2023, correction 2023). And the only randomised trial in older women (56 participants, 24 weeks, 5 g a day) showed no effect on cognition or mood.

I wrote about this in more detail in a separate piece — "Creatine and the Brain: a Scientific Look Without Sugarcoating".

It does not speed up recovery. 13 trials: no effect on muscle soreness, strength recovery, range of motion or inflammation — not at 30 minutes, not at 96 hours.

None of this is a reason to give creatine up. It's a reason to buy it for what it actually does.

Safety: what's true and what's a myth

The overall picture is calm. Across an analysis of 685 clinical trials, side effects were reported in 13.7% of creatine studies versus 13.2% of placebo studies — no difference (p=0.776). The longest trial included 1,741 people taking 10 g a day for 5 to 8 years: no differences in adverse events were detected (JAMA, 2015).

Now the specific fears.

"Creatine wrecks your kidneys." This is the most common worry — and the most understandable misunderstanding. Creatine naturally breaks down into creatinine, and creatinine is precisely the marker used in blood tests to assess kidney function. So the number on the form really does rise: on average by 0.13 mg/dL. Urea, meanwhile, doesn't move.

The most convincing evidence here comes from studies that assessed the kidneys with methods independent of creatinine (isotope-measured filtration, cystatin C): in people with type 2 diabetes, in older adults, and in people training on a high-protein diet, kidney function did not change (review by Longobardi et al., Nutrients, 2023).

But the conclusion isn't "ignore it" — it's something else: raised creatinine also happens when kidney function is genuinely declining, and that single marker cannot tell the two apart. Which is why you tell your doctor (see below).

"Creatine makes your hair fall out." This whole story comes from one 2009 study in 20 rugby players, which measured hormones and never measured hair at all. In 17 years it has not been replicated. The one study that did measure hair (38 men, 12 weeks) found no difference in hair density, hair count or hormones (Lak et al., JISSN, 2025). Both were male-only: in women this has never been studied either way. So, honestly: the mechanism people fear has never turned into actual hair loss in anyone — but I can't offer you an absolute guarantee either.

"Bloating and a puffy face." Water is genuinely retained — predominantly inside the muscle cells. No study has ever measured subcutaneous water or facial puffiness. So this fear is neither confirmed nor refuted.

"Cramps and dehydration." Here the data point the other way: a systematic review of 10 high-quality trials found an effect on core body temperature of 0.03 °C — that is, none. In a season-long observation of athletes, those taking creatine had fewer cramps, not more.

What genuinely does happen: stomach discomfort from too large a single serving. The fix is simple — no more than 5 g at a time, with food and plenty of water. With a split dose, the complaint rate in one trial was actually lower than in the placebo group.

How to take it: the practical protocol

My recommendation for most readers is the most boring and the most effective.

| Question | Answer | |---|---| | What to buy | Plain creatine monohydrate powder. Not HCl, not "buffered", not liquid, not gummies | | Dose | 3–5 g a day, every day | | Loading phase | Optional. 20 g a day for 6 days and 3 g a day for 28 days reach the same saturation — the only difference is speed | | When | Doesn't matter much. Before or after training, and on rest days too. Consistency beats timing | | With what | With a meal. With protein and carbohydrates, retention is about 25% higher | | When to expect an effect | 3–4 weeks on 3–5 g. In women, judge it over months of consistent training, not weeks | | Do you need breaks? | No evidence that you do |

Three clarifications that will save you money and worry:

• Expensive forms are not better. In an 8-week trial, HCl showed no statistically significant advantage over monohydrate on any measure. "Buffered" — the same. Monohydrate is absorbed almost completely: there isn't much left to improve.
• Liquid creatine and gummies — skip them. In solution, creatine gradually converts into inactive creatinine. Mix it right before you drink it. Gummies also cost several times more than powder.
• Grit at the bottom is not an absorption problem. At room temperature, 5 g fully dissolves in about 350 ml. In a small glass of cold water you'll see sediment. Add water, stir, drink — the dose still counts.

And about quality. Sports nutrition is an industry with a contamination history: in a study of 634 supplements bought in 2000–2001, 14.8% contained undeclared anabolic steroids. Things are better today — which is exactly why certification exists. Look for independent batch testing on the tub: Informed Sport or NSF Certified for Sport.

Women: what we know — and what we don't

Almost nobody talks about this, and someone should.

Of 656 creatine studies, only 58 — that is 9% — were conducted exclusively in women (de Guingand et al., Nutrients, 2020). Practically the entire standard protocol, including the famous loading scheme, is built on male data: the foundational 1996 dosing study had 31 men and zero women.

When the data are split by sex, the effect in women looks smaller: +1.46 kg lean mass in men versus +0.29 kg in women (Delpino, 2022). In a review of 27 studies in active women, creatine beat placebo in only 3 of 11 strength studies (Tam et al., Nutrients, 2025).

But here's what matters most: this is not proof that creatine doesn't work for women. Female subgroups are almost always small and statistically weak — and the largest analysis of 100 studies found no sex difference at all. The honest conclusion is this: the effect in women is less well measured, not proven absent. That's a gap in the science, not a verdict.

A few more things worth knowing:

• Perimenopause is barely studied. The one small trial used non-standard forms of creatine at doses 3–5 times lower than usual. Any "creatine for perimenopause" promise is extrapolation.
• Smart scales will mislead you. In 13 dancers, DXA "lean mass" rose by 1.7 kg while body mass rose only 0.7 kg. These devices count water as tissue. Don't judge the effect by the scale — judge it by what you lift and how you feel.
• Fluid retention depends on your cycle phase. In the luteal phase water increases; in the follicular phase it doesn't. And even then there was no significant difference in body mass.

Who shouldn't take it — and when you need a doctor

This is the section the whole article was worth writing for. 🔴

Do not start without medical supervision if you have:

• Kidney disease, reduced filtration, a single kidney or you're on dialysis. There are no controlled trials in this group. The expert position isn't "dangerous", it's "not studied": the decision is made with your doctor, monitored with markers that don't depend on creatinine.
• Pregnancy. There are no completed randomised trials in humans. Outside research settings it is not recommended.
• Breastfeeding. Never studied at all. Neither "safe" nor "unsafe" can honestly be said — the data simply don't exist.

Discuss it in advance if:

• You have bipolar disorder. This is the one psychiatric caution with a real signal: in a randomised trial in bipolar depression, two of 17 participants on 6 g a day switched into hypomania. That doesn't mean "creatine causes mania" — it means the decision belongs to your psychiatrist.
• You're under 18. Here experts genuinely disagree. The decision belongs to a paediatrician or sports physician.
• You regularly take NSAIDs, diuretics or immunosuppressants. These combinations have never been studied in people. So both "it's dangerous" and "there are no interactions" are wrong. What's right: not studied — ask your doctor.

And the most practical line in the whole article:

If you're having a blood test — tell your doctor or nurse that you take creatine.

Your creatinine will read higher, and that's expected. But creatinine alone cannot distinguish a harmless rise from a genuine drop in kidney function. If accuracy matters, there is cystatin C — a marker creatine doesn't affect. Discuss it with your doctor.

Separately: don't go looking online for "how many days to stop creatine before a blood test". No such interval has ever been established, and the numbers circulating online aren't based on a single study.

Red flags — stop and see a doctor (these symptoms need attention regardless of any supplement): a sharp drop in urine output; dark, cola-coloured urine; new swelling of the face or legs, breathlessness; severe unexplained muscle pain or weakness; persistent nausea and vomiting.

Gaining 1–3 kg in the first week of loading is expected water. Gaining noticeably more, especially with swelling and breathlessness, is not a creatine effect — that's one for the doctor.

Frequently asked questions

Do I need creatine if I don't go to the gym? Probably not. Almost all the proven benefit appears alongside resistance training. Without it, you're paying for a very modest effect.

I'm vegetarian — do I need it more? Possibly. Creatine comes almost entirely from meat and fish, and in one trial vegetarians started lower and gained more. But it isn't universal: in a 2025 study, vegans' baseline levels were comparable to omnivores'. Let's put it this way: it's worth trying, with no guarantees.

Is it true that women need a higher dose? There's no reliable data for it. All the large long-term trials in women used 5 g a day, or around 0.1 g per kg of body weight. Recommendations of 20 g a day for postmenopausal women have never been compared against a standard dose.

Can I take creatine with coffee? Yes. The claim that coffee "cancels out" creatine is an unresolved question of effectiveness, not of safety. There's no evidence of harm.

How long until I know whether it works? Give it 4–8 weeks of consistent use and consistent training, and judge it not by the scale but by the weights you're lifting and how you feel. If nothing has changed in that time — that's your answer, and it's fine.

Do I need to cycle off? No evidence that you do. After stopping, stores return to baseline over roughly 30 days.

Small steps for this week

You don't need to decide everything at once. Pick one:

1. Foundation first. If your protein is low and your sleep is broken, start there. A supplement on a poor base will give you almost nothing.
2. If you train with weights at least twice a week, creatine makes sense. If not, start with the training.
3. Get plain monohydrate powder with independent certification. No loading, 3–5 g a day.
4. Mix it in plenty of water, take it with food, at the same time each day.
5. Evaluate after 4–8 weeks — by strength and how you feel, not by the number on the scale.
6. Going for a blood test — mention the creatine.

And finally — the most important thing

Creatine is a good tool. Calm, inexpensive, well studied. It gives a small but real advantage to those already doing the main things: training, eating enough protein, sleeping well.

But it won't replace any of them. In The Better Plate approach the order is always the same: the plate, sleep and movement first — supplements only after that. Not because supplements are bad, but because on a good foundation they work far more noticeably.

And please, no perfectionism. 💚 If you decide not to take creatine, you lose nothing that truly matters. If you decide to take it, do it consciously, calmly and with your eyes open. That is what caring for yourself actually looks like.

Educational note: this material is for information only and does not replace consultation with a doctor. Before starting any supplement — especially with kidney disease, in pregnancy, while breastfeeding, on medication, or with a psychiatric diagnosis — consult a professional. The Better Plate uses educational principles of healthy eating, including ideas inspired by the Harvard Healthy Eating Plate; Better With Anna is not affiliated with Harvard University.

Want to understand what your body is actually missing before you buy supplements? Start with a biomarker analysis or an express consultation — so decisions are made from data, not advertising. And if mindful nutrition is your thing, visit the Better With Anna homepage and read "Nutraceuticals without fanaticism" — on when supplements are genuinely needed. 🌱

Sincerely yours, Anna Bertoldi