Creatine is one of the most thoroughly researched supplements on the market. Praised for its ability to boost strength, power, and muscle mass, it’s earned die-hard fans everywhere, from gym rats to endurance athletes. Research in recent years has also highlighted a surprising bonus. Creatine may support memory, reasoning, and overall mental function by helping fuel the brain and reducing mental fatigue.
But despite all those proven benefits, the supplement’s reputation has taken a few hits. Rumor mills, locker-room lore, and Reddit threads have long insisted it leads to weight gain, and that claim has stuck around. To sort out what’s real and what’s bro-science, we turned to expert dietitians and nutritionists who break down the truth.
Does Creatine Make You Gain Weight?
“In short, creatine does not cause actual weight gain, but can cause the number on the scale to increase,” says Tiffany Ma, a board-certified sports registered dietitian. “During the initial phases of supplementation, water is being pulled into muscle cells as a result of saturation of phosphocreatine in the skeletal muscle. The body reacts to this saturation of creatine by balancing it out with water.”
In other words, early water retention is normal (and temporary). Studies show that during the first few days of taking creatine, your muscles hold onto a bit more fluid, which can nudge the scale upward. But this effect usually levels off quickly. When people notice a more lasting change in weight, it’s rarely water. Instead, it’s typically a small increase in muscle mass, which is exactly what creatine is designed to support when paired with resistance training.
What’s a Loading Phase?
The amount of temporary weight you might gain also depends on whether you do a creatine loading phase. A loading phase is a short period of taking a higher dose of creatine to quickly saturate your muscles. Typically, it involves 20 to 25 grams per day, split into multiple servings, for about 5 to 7 days before dropping to a maintenance dose of 3 to 5 grams.
“Skipping the loading phase does not reduce the long-term benefits, but it makes the change slower and often less noticeable in the beginning,” says Ma. “A standard daily dose without loading gradually increases muscle creatine stores, so any water retention tends to be more subtle and spread out over weeks rather than happening abruptly in a few days.”
According to Dr. Mark Kovacs, PhD, FACSM, CSCS, people who load usually see a quick bump of about one to three pounds within the first week. After that, weight may continue to rise slightly, usually another pound or so, more gradually over the next three to four weeks.
Related: This Is The Best Time to Take Creatine, According to Science
How Long Does Creatine Take to Work?
The effects of creatine depend on whether you use a loading phase, how much you take, and your consistency. Ma says most people start noticing results within about two weeks, but it varies based on your protocol.
“If someone uses a loading approach, their muscles saturate more quickly, and weight changes can happen within the first week,” she says. “Without loading, the process is slower, and many people see gradual changes over two to four weeks. Some individuals may not notice much change at all, even if creatine is working, because the response varies based on muscle mass, training routine, hydration, and baseline creatine levels.”
