Medical Disclaimer: The information in this article is for educational purposes only and is not intended as medical advice, diagnosis, or treatment. Always consult a licensed healthcare provider before starting any new supplement, especially if you have kidney concerns.
Not long ago, one of my patients, a woman in her fifties who has never set foot in a gym in her life, asked me if she should be taking creatine. She had seen a clip online claiming it could help her memory and her bones. A few weeks later, a college student asked me almost the opposite question, worried that the creatine his roommate kept pushing on him would somehow damage his kidneys. Same supplement, two completely different conversations, and both of them only half right.
Creatine has quietly become one of the most talked-about supplements outside of sports nutrition circles, and the claims attached to it have expanded far beyond muscle gain. Some of that expansion is backed by genuine, growing research. Some of it is enthusiasm running ahead of the evidence. It is worth separating the two clearly.
What Creatine Actually Is
Creatine is not a synthetic performance drug. It is a naturally occurring compound made in the liver, kidneys, and pancreas from three amino acids, and it is also found in foods like red meat and fish. The body stores most of it in skeletal muscle, where it is used to rapidly regenerate ATP, the molecule your cells use for quick bursts of energy.
This is why creatine has traditionally been associated with strength training and explosive sports. When your muscles need a fast energy source for a heavy lift or a sprint, creatine phosphate is one of the first systems the body draws on.
What has changed in recent years is a growing body of research looking at what creatine does outside the muscle, particularly in the brain, where creatine also plays a role in cellular energy production.
The Muscle and Strength Evidence, in Brief
This part of the research is well established. Creatine monohydrate is one of the most extensively studied supplements in existence, with decades of trials showing it can:
- Modestly increase strength and power output during resistance training
- Support lean muscle mass gains when combined with training
- Improve performance in short, high-intensity bursts of activity
- Aid recovery between sets and sessions
This is not new or controversial information. What is newer, and more relevant to people who never plan to touch a barbell, is the research on cognition, aging, and muscle preservation later in life.
Creatine and Brain Function
Because neurons are highly energy-demanding cells, and creatine supports cellular energy production, researchers have looked at whether supplementation affects cognitive performance, particularly under conditions of stress, sleep deprivation, or aging.
The current picture, based on smaller trials rather than large-scale, definitive studies, suggests:
- Some evidence of improved performance on memory and reasoning tasks, particularly in situations involving mental fatigue or sleep deprivation
- Possible modest benefit in older adults, where brain creatine stores tend to be lower
- Interest in creatine as a supportive measure in certain neurological conditions, though this research is still early and should not be interpreted as treatment
This is a genuinely exciting area of research, but it is important to be precise about the language. “Some evidence of modest benefit under specific conditions” is very different from “creatine boosts your brain,” which is the version that tends to circulate online.
Creatine and Aging Muscle
One of the more clinically meaningful applications is in older adults. As people age, they naturally lose muscle mass and strength, a process called sarcopenia, which is closely linked to falls, frailty, and loss of independence.
Research combining creatine supplementation with resistance exercise in older adults has shown it can help preserve muscle mass and strength more effectively than exercise alone. This is one of the more practically important findings for non-athletes, particularly people in their sixties and beyond who are trying to stay strong and independent.
It is worth being clear that creatine alone, without any physical activity, is unlikely to meaningfully build or preserve muscle. It works as a support to exercise, not a replacement for it.
The Kidney Question
This is the single most common concern I hear, and it deserves a direct answer. In people with healthy kidney function, decades of research, including long-term studies, have not shown that standard creatine doses cause kidney damage. Creatine does slightly raise creatinine, a marker doctors use to assess kidney function, but this reflects normal creatine metabolism rather than actual kidney injury, and it can sometimes confuse routine blood test interpretation.
The caveat matters: people with pre-existing kidney disease, or those taking medications that affect kidney function, should not start creatine without speaking to their doctor first, since the safety data in that specific population is far more limited.
Who Might Reasonably Consider It
Outside of athletes, creatine may be reasonably considered by:
- Older adults working with a doctor or physiotherapist on a resistance training program to preserve muscle and strength
- Vegetarians and vegans, since dietary creatine mainly comes from meat and fish, meaning this group typically has lower baseline stores
- People under significant sleep deprivation or mental fatigue for sustained periods, based on the early cognitive research, though this is a softer recommendation than the muscle-related evidence
Who Should Be Cautious
- Anyone with existing kidney disease or a single functioning kidney
- People taking nephrotoxic medications, meaning drugs that can stress kidney function
- Anyone pregnant or breastfeeding, due to insufficient safety data
- People relying on it as a substitute for medical evaluation of persistent fatigue or cognitive concerns, rather than as a supportive measure
Common Side Effects
Creatine is generally well tolerated. The most commonly reported effects are mild and include water retention, particularly in the first week or two, and occasional stomach discomfort if taken in large single doses. Spreading the dose out or taking it with food typically resolves this. Serious side effects are rare in people without underlying kidney disease.
A Realistic Way to Think About It
Creatine has moved from a niche gym supplement to one of the more well-supported options in general nutrition science, but the strength of the evidence varies a lot depending on which claim you are looking at. The muscle and strength research is strong. The healthy-kidney safety research is strong. The cognitive and aging research is promising but still developing, and should be treated as such rather than as settled fact.
If you are considering it, the most sensible approach is the least exciting one: start with a normal dose, stay well hydrated, pair it with adequate protein intake and, where relevant, resistance exercise, and speak to your doctor first if you have any kidney concerns or take regular medication.
Frequently Asked Questions
Q1: Do I need to “load” creatine with a high dose at the start?
No, loading is optional. It saturates muscle stores faster, but a consistent daily maintenance dose reaches the same saturation point over a few weeks without a loading phase.
Q2: Is creatine safe for teenagers?
This should be discussed with a pediatrician or family doctor. Most safety research has been conducted in adults, and use in younger people should be individually assessed rather than self-directed.
Q3: Will creatine make me gain weight?
It can cause a small increase in water weight within the muscle cells in the first couple of weeks, which is different from fat gain. This is expected and not a sign of harm.
Q4: Can I take creatine if I don’t work out at all?
You can, though the muscle-related benefits depend heavily on resistance training. Any potential cognitive benefit is less dependent on exercise, but the evidence there is still developing.
Q5: Does creatine interact with medications?
It can be relevant for people on certain kidney-affecting medications or those with existing kidney disease. Always check with a doctor or pharmacist if you take regular prescription medication.
This article is intended for general educational purposes and does not replace personalized medical advice. If you have kidney concerns, are on regular medication, or are considering a new supplement for a specific health goal, please consult a licensed healthcare professional first.
I am a final-year MBBS candidate. After years of watching patients misunderstand their own diagnoses, I started writing — because accurate health information should not require a medical degree to understand. I specialise in health, health tech, and public health content, combining clinical training with a passion for making medicine accessible to everyone.”
