What is a proven side effect of creatine use in healthy individuals?

Weight gain is a well-documented side effect of creatine supplementation in healthy individuals. This increase in body weight primarily occurs due to two mechanisms. First, creatine helps to increase the water content in muscles, which can lead to a greater water retention effect, thereby increasing overall body mass. Second, creatine can enhance the muscle’s ability to perform higher-intensity training by promoting more significant gains in strength and muscle mass over time. This physiological response can translate to an increase in lean body mass as well.

While nausea, increased heart rate, and muscle cramps may be reported by some individuals using creatine, they are not as consistently recognized among the general side effects across broader populations as weight gain is. This makes weight gain a more reliably observed outcome associated with creatine supplementation in otherwise healthy individuals.