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Published 13 Sep 2026
Creatine is one of the most studied supplements there is, which makes this an unusually answerable question, up to a point. What follows separates what is documented from what is repeated, and says where the evidence runs out rather than filling the gap with reassurance.
Healthy adults who train. If you have kidney or liver problems, are pregnant or breastfeeding, take prescription medication, or are under eighteen, this is a question for a doctor or a pharmacist rather than for a page. Creatine is not a neutral substance for everyone, and none of what follows is written with those situations in mind.
Three effects come up often enough to be worth stating one by one.
| Reported effect | What the evidence says |
|---|---|
| Weight gain in the first weeks | consistent; water drawn into muscle, not fat (separate piece) |
| Stomach discomfort: cramping, bloating, loose stools | reported mostly at larger single doses, much less at the smaller daily amount |
| Muscle cramps | studies that looked for a cramping effect have generally not found one; some found fewer cramps in the creatine groups |
That third row is worth stating plainly, because the belief is widespread and the research does not support it.
This is the concern that drives most of the searching, and it has a clear origin. Creatine raises blood creatinine, the marker used to estimate kidney function. A routine blood test can therefore look worse without kidney function having changed. That is a measurement artefact, and it is well described.
In healthy adults, studies looking specifically at kidney markers have not found harm at normal doses, including trials running for months and some considerably longer. That is a reasonable body of evidence, and it is why “creatine damages your kidneys” is not supported for that group.
What it does not establish is safety in people who already have reduced kidney function, because those people are excluded from the trials. Absence of harm in healthy adults is not evidence of safety in kidney disease, and conflating the two is the most common error on pages about this. If that is you, the box at the top is the whole answer.
One practical note: if you are having blood work done, mention that you take creatine. It can save a conversation about a raised creatinine that has a simple explanation.
This one traces back to a single small study in rugby players, published in 2009, which reported a rise in a hormone associated with male pattern baldness. It did not measure hair loss.
That study has not been replicated since, and later work has generally not reproduced the hormonal finding. So the position is narrow: one small study, one indirect marker, no demonstrated effect on hair, no replication. That is neither “proven safe” nor “proven to cause hair loss”. It is a thin finding carried a long way beyond what it can bear.
It is also a good example of how a single result becomes a widely held belief when everyone cites the headline and nobody checks what was measured.
The research is overwhelmingly in healthy adults, and heavily weighted towards younger men. Several groups are thinly represented or absent: adolescents, older adults, people who are pregnant or breastfeeding, and people with liver or kidney conditions.
For those groups the correct statement is not that creatine is risky. It is that the question has not been answered, and a page cannot answer it for you. That is a real limit, not a formality, and it is why this site does not extend its conclusions to people the studies did not include.
Long-term use is better documented than it used to be, with trials running several years. Still, “several years in healthy adults under study conditions” is a narrower claim than “safe forever for everyone”.
It is not medical advice, and this is not a medical site. The organisations at the top of the search results for this question are clinics and medical bodies, and that is appropriate. They can speak to your situation in a way a training app cannot.
What this page can do is report what the research says with the hedging left in. That turns out to be hard to find between the pages that promise nothing can go wrong and the ones that imply everything can.
In healthy adults, studies looking at kidney markers have not found harm at normal doses. It does raise blood creatinine, which can make a routine test look worse without function having changed. None of that speaks to people who already have reduced kidney function; for them this is a question for a doctor.
There is one small study from 2009 in rugby players reporting a rise in a related hormone. It did not measure hair loss, it has not been replicated, and later work has generally not reproduced the finding. That is a thin basis for either conclusion.
The research points the other way: trials looking for a cramping effect have generally not found one, and some reported fewer cramps. The belief is common and the evidence does not support it.
Stomach discomfort is reported, mostly at larger single doses. It is much less common at the smaller daily amount, and taking it with food and plenty of water helps.
Trials running several years in healthy adults have not found harm, which is a reasonable body of evidence. It is still a narrower statement than “safe indefinitely for everyone”, and it does not cover the groups the studies excluded.
More reading: the safety question in full · the weight gain · all posts
There is no creatine setting in the app, nothing to log, and nothing being sold here. This page exists because it is a question people who lift keep asking, and because a straight answer is harder to find than it should be: what is known, and where it stops. That is the same thing the app does with the numbers it does own: your training and your food, worked out from your own data, with the rule shown.