Browse evidence-based analysis of health-related claims and assertions
Your muscles use creatine like a fast-charging battery to keep energy flowing during intense exercise, shuttling it quickly where it’s needed most—like a delivery service for power.
When male mice can't transport creatine properly, their muscles show signs of weakening because key growth signals are turned down and breakdown processes are turned up.
Male mice that can't transport creatine properly in their muscles have mitochondria that aren't working efficiently — they're using energy but not making as much usable fuel (ATP), kind of like a car engine that's revving but not moving.
In male mice that can't transport creatine properly, their muscle mitochondria get way bigger, move to the wrong part of the muscle cell, and get damaged inside — like tiny powerplants going haywire.
In male mice that can't transport creatine properly, their muscle cell powerhouses don't handle calcium well when triggered, even though calcium levels look normal at rest.
Male mice that can't transport creatine properly have super weak muscles — their grip gets way worse as they age, and their leg muscles can't produce nearly as much force or power as normal mice.
Male mice that can't transport creatine properly have much weaker muscles — their muscle fibers shrink by over two-thirds and take up less space in the muscle, showing serious damage to fast-moving muscle types.
When there's enough creatine in your muscle cells, it can hide the negative effects of exercise on how muscles use energy, meaning creatine might help keep energy flow working smoothly even after a workout.
If you cycle for two hours and don't have creatine in your muscles, your muscle cells' energy powerhouses become less responsive to a key energy signal, which might mean energy can't move as easily without creatine.
After a couple of hours of moderate cycling, men's muscles may get better at shuttling energy around, helping them perform better in future workouts.
Even though their energy enzyme levels didn't change, rat hearts showed different energy processing in one specific area after living in low-oxygen conditions for three weeks—hinting that heart energy control might work differently in different parts.
Rats breathing low oxygen for three weeks show weaker heart energy systems, especially in the part of the heart that pumps blood, suggesting their heart cells aren’t moving energy around as well.
Rats exposed to low oxygen for three weeks show that their heart cells don’t respond as well to creatine, which might mean their energy system isn’t working as efficiently in low-oxygen conditions.
In resting muscles, the way energy molecules move isn't slowed down by how far they have to travel — they can get where they need to go just fine.
In resting human muscles, a molecule called phosphocreatine can travel far enough to deliver energy where it's needed, even between distant parts of the muscle cell — kind of like a tiny energy shuttle making the rounds.
In healthy human muscles, a molecule called phosphocreatine moves around at a specific speed when there's nothing blocking it — and scientists use that speed to understand how energy gets shuttled inside cells.
In healthy adult muscles, a molecule called phosphocreatine doesn't move freely — it's kind of boxed in by cell walls, and the size of those boxes matches the size of the muscle fibers themselves.
In healthy adult muscles at rest, a molecule called phosphocreatine moves more easily along the length of muscle fibers than across them—like sliding along a hallway instead of pushing through walls—because the muscle's internal structure guides its movement.
Taking creatine is safe for kids, teens, and adults of all ages, and doesn’t cause more side effects than a sugar pill, according to studies that looked at people from young children to older adults.
Taking creatine doesn’t seem to hurt your kidneys — studies show no difference in kidney health between people who take creatine and those who don’t, even after hundreds of trials.
People who take creatine don't seem to get more muscle cramps or pain than those who don't — even though a few more users reported it, the difference isn't big enough to matter.
Taking creatine doesn’t seem to cause more stomach issues than a fake pill — about the same number of people get digestive problems whether they take creatine or not.
Taking creatine — whether it's the common monohydrate type or another form — doesn't seem to cause more side effects than a fake pill, even in kids, older adults, healthy people, or those with medical conditions.
Creatine doesn’t seem to cause many problems in real life — out of millions of reports, hardly any mention it, and most of those also involve other supplements or medicines.