Yes, when taking creatine, you might experience a very small increase in body weight.

“Some people, but not all, experience a small amount of weight gain when taking creatine,” Grant Tinsley, Ph.D., a professor and researcher at Texas Tech University, tells mindbodygreen.

However, Tinsley explains that this weight gain is due to water storage, not fat gain.

The small amount of weight that some people experience when taking creatine is typically due to increased creatine concentrations and water storage in the muscles. “While this effect has been observed in multiple studies, not all individuals or groups experience this,” he reiterates. 

Studies have shown mixed results when it comes to water weight gain and creatine use. Some studies have found that during the first few days of creatine supplementation, some people experience increases in total body water (TBW), extracellular body water (ECW), and intracellular water (ICW).

For example, a 2017 study published in Medicine & Science in Sports & Exercise that included 18 male cyclists found that when the participants followed a creatine-loading phase that involved taking 20 grams of creatine per day for five days, their TBW increased by 1.4%. But, other studies have found that creatine has no significant impact on the body’s water levels, especially over the long term.

In addition to water weight, creatine can help support muscle mass gain when combined with resistance exercise and proper nutrition. Gaining muscle mass can impact your body weight, but this is usually viewed as a positive side effect of creatine supplementation and is the reason many people use creatine.