In the world of sports supplements, creatine is a rarity -- a substance with a proven track record of safety and effectiveness that is allowed by all major competitive governing bodies. It has also shown promise in treating a number of chronic diseases, and is available over the counter at modest cost. One area in which it has not shown promise, however, is weight loss, though creatine may have an indirect positive effect.
Creatine is most commonly used as a sports supplement, but it is also used in treating a variety of medical conditions such as Parkinson's disease, ALS and rheumatoid arthritis. The common thread is that all these situations require an increase in strength and muscular control -- creatine doesn't actually build muscle, but it helps the muscles draw water away from the rest of the body. The increased hydration facilitates efficient nerve signaling, resulting in a faster response time and better control of muscle contractions. It also helps form adenosine triphosphate, which powers muscular contractions, resulting in a greater amount of available energy within the muscles themselves.
Because creatine helps your muscles perform better, you'll be able to work out more effectively. It won't help you break the six-minute mile, but it may help you graduate to heavier dumbbells. Although cardio work is what burns the fat, lifting weights increases your muscle mass, and consequently, your calorie expenditure. Cultivating lean mass can help you lose weight over time as long as you don't increase your caloric intake to match your increased output. Although the same process can occur without creatine, it may happen a little faster with it.
Creatine is not a weight loss drug. It has no thermogenic properties, it is not a fat blocker, and it won't do the work for you. It can help you perform better when you work out, but it will be completely ineffective if you don't. In fact, because creatine pulls water into your muscles, you may actually gain 1 to 3 lbs. during the loading phase. As you build muscle, you will gain more weight. Building muscle will help you burn fat, but the number on the scale may go up.
The Bottom Line
The only thing that can make you lose weight is eating fewer calories than you burn, and the only thing that can keep you from losing weight is burning fewer calories than you eat. If you're looking for the "magic" weight loss pill, creatine isn't it. If you want something to help you build a little muscle tone while you get in shape, creatine could help. Creatine is generally recognized as safe, but it's long-term effects have not been studied, and it doesn't seem to affect people older than 60. If you are taking creatine for a medical reason, consult your doctor about your weight loss intentions -- she may be able to switch your medication or recommend a plan that will suit your situation.