Taking creatine supplements may increase the amount of creatine in the muscles. Muscles may be able to generate more energy or generate energy at a faster rate. Some people think that taking creatine supplements along with training will improve performance by providing quick bursts of intense energy for activities such as sprinting and weightlifting.

In another case, supplements touted as "myostatin blockers" were formulated from a type of sea algae. In a test tube, they effectively blocked the activity of the protein myostatin, which inhibits muscular growth in the body. The supplement ads implied that they'd enable you to develop unprecedented levels of muscular growth, but as it turned out, they didn't actually work in the human body.
Don’t make the mistake of trying to bulk up when you should be on a diet. While you might have muscle on your mind, most people need to get leaner first. If you’re fat and you start eating for size, you’re only going to get fatter. Get rid of the excess blubber first, to the point where you can see some abs, and then worry about getting big. You should be as low as 12% body fat before you change your diet up to focus on mass gain. That will ensure that your insulin sensitivity is high. When it is, you can eat more carbs and your body won’t store them as fat.

Synthesis primarily takes place in the kidney and liver, with creatine then being transported to the muscles via the blood. The majority of the human body's total creatine and phosphocreatine stores is located in skeletal muscle, while the remainder is distributed in the blood, brain, and other tissues.[17][18][20] Typically, creatine is produced endogenously at an estimated rate of about 8.3 mmol or 1 gram per day in young adults.[16][17] Creatine is also obtained through the diet at a rate of about 1 gram per day from an omnivorous diet.[17][18] Some small studies suggest that total muscle creatine is significantly lower in vegetarians than non-vegetarians, as expected since foods of animal origin are the primary source of creatine. However, subjects happened to show the same levels after using supplements.[21]