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Published 13 Sep 2026
Creatine is among the most studied supplements available, and for healthy adults the evidence is reassuring. That sentence needs both halves. Pages that drop the second half and call it safe without qualification make a claim the research does not support, in the same way the pages warning about your kidneys do.
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.
In healthy adults, at the doses normally used, trials have not found harm, and a 2017 review of that evidence reaches the same conclusion. That includes studies looking specifically at kidney and liver markers, and studies running for months to years. The volume of research here is unusual for a supplement, and it is why creatine is treated differently from most of the shelf it sits on.
The reported effects are modest and mostly practical:
Both have their own pieces.
Safety in people the studies did not include. That is not a technicality. Trials deliberately exclude people with kidney or liver disease, so the conclusions do not extend to them. A page that calls creatine safe, full stop, has quietly generalised beyond its evidence.
The same applies to adolescents, to people who are pregnant or breastfeeding, and to anyone on medication that affects the kidneys. For those groups the right statement is that the question has not been answered, not that it has been answered reassuringly.
And “safe” carries a lot of weight in the original question. Safe at what dose, for how long, alongside what else? The research answers a specific version: normal doses, healthy adults, timescales up to a few years.
Creatine raises blood creatinine, which is the marker used to estimate kidney function. A test can look worse without anything having changed. This is well described, and it is the root of most of the worry.
It is also why mentioning creatine to whoever ordered your blood work is worth doing. The fuller version is in the piece on side effects.
Supplements are regulated differently from medicines in most countries. What is in the tub is a manufacturing question, not a question about creatine. Independent testing programmes exist for that reason.
This site does not name products or rate manufacturers. That is outside what a training app can usefully judge, and it changes over time. Worth knowing that the question exists and that it is separate from whether the compound itself is well studied.
The organisations at the top of the search results for this question are clinics and medical bodies. That is the right order, and this page is not trying to displace them.
What it offers instead is the shape of the evidence with its limits intact: good support for one group, silence for several others, and a clear line between the two. If your situation falls on the other side of that line, the box at the top is not a disclaimer. It is the answer.
For healthy adults at normal doses, the evidence is reassuring and unusually extensive. For people with kidney or liver conditions, people who are pregnant or breastfeeding, under-eighteens and people on medication, the research does not answer the question. That is a conversation with a doctor.
The research in adolescents is thin, so the answer is that it has not been established, not that it is fine. That makes it a question for a doctor.
No. Creatine is a compound found in food, mostly meat and fish, and made by your own body. It works by increasing an energy store in muscle and is not a hormone.
There is no established reason to. The idea comes by analogy from compounds that work very differently, and studies of continuous use have not found a reason for breaks.
If you have a health condition, take medication, are pregnant or breastfeeding, or are under eighteen: yes, and that is the point of the box at the top. Otherwise the research in healthy adults is what this page describes.
More reading: side effects in detail · the standard doses · 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.