Creatine is a natural amino acid your body produces, but it's also available over-the-counter as a supplement. According to the University of Maryland Medical Center, creatine supplements make up a $14 million industry in the United States alone. Despite its popularity and growing mound of evidence supporting its efficacy when used by strength-training athletes, concern about creatine causing dehydration and other side effects still exist. According to the UMMC, dehydration is not a common side effect associated with short-term creatine supplementation. Consult your doctor before trying creatine supplements.
Your body stores creatine primarily in your muscle tissue as creatine phosphate, also called "phosphocreatine." The stored creatine helps supply your muscles with energy during explosive exercise, such as lifting weights or sprinting. According to the UMMC, creatine supplements don't benefit endurance athletes. Your muscle tissue does reach a saturation point when it comes to storing phosphocreatine, so taking more than the recommended dosage is not effective and potentially increases your risk of side effects.
The concern about dehydration when taking creatine supplements is largely due to your muscle tissue retaining water. This is the reason you may experience weight gain after just a week of supplementing creatine. UMMC doesn't list dehydration as a common side effect of creatine supplementation; however, it does list muscle cramps. Muscle cramping occurs frequently when your body is not getting enough water. So, the best approach is to increase your intake of water by sipping it constantly throughout the day as well as during and after your workouts.
A 2006 laboratory study published in the "Journal of Athletic Training" examined how creatine use affects men in terms of dehydration, muscle cramping and heat tolerance. This study focused on 22-year-old males taking 21.6 grams of creatine per day for a period of one-week -- the typical dosage during the "loading phase." Scientists tested the men under various exercise conditions to see if increasing the heat caused the men taking creatine to dehydrate more quickly compared to men not taking the creatine but exercising under the same conditions. The results showed no significant differences between men taking creatine and those not taking the supplement. This study suggests that short term use of creatine -- up to one-week -- doesn't cause dehydration.
Certain medicines may interact negatively with creatine supplements. According to the UMMC, if you take diuretics or consume large amounts of caffeine while taking creatine supplements, your risk of dehydration increases. Additionally, caffeine may decrease your body's ability to utilize creatine effectively during exercise. You may want to avoid caffeinated beverages immediately before, during and after your workouts. Most importantly, drink water constantly throughout the day to keep your body properly hydrated.