Creatine is the single most studied supplement on the market. A naturally occurring substance within your body, creatine is formed from the amino acids glycine, methionine and arginine. Creatine can also be found in high levels in red meats.
Through a number of studies, creatine supplementation has already been proven to increase fat-free mass and strength when paired with resistance training. However, there was little research on creatine supplementation timing and the effectiveness of different timing.
A study done by Jose Antonio and Victoria Ciccone published in the Journal of the International Society of Sports Nutrition has found the answer to that question. The study showed that taking creatine post-workout is superior to taking it pre-workout, from a strength and body composition standpoint.
You can read the full research article here.