When most people think "supplements," they think of anabolic steroids-powerful drugs that cause intense muscle gains, have scary side effects, and are banned from all major sporting events. However, most body building supplements are perfectly legal-and many do not have serious side effects, especially when taken in moderation.

First, the disclaimer: we're not doctors, and we can't give you advice on which supplements to take based on your individual situation. If you have concerns about specific supplements or any health condition that might play a part in the supplements you use, consult a doctor. That being said, here's an overview of some of the major supplements body builders use to get big.

Creatine. Creatine is a muscle-building acid that's made naturally in the body. In supplement form, it enhances a muscle's ability to maintain power during brief, high-intensity exercises. It also reduces fatigue, lessening the burning sensation you get from lactic acid buildup in your muscles and delaying muscle failure. It allows you to work out stronger and harder, encouraging your body to build muscle more effectively. Creatine is generally safe for everybody, although studies on its effects on people with diabetes and kidney problems haven't been completed.

Protein. Protein provides the building blocks for muscle, hormones, tissues, and enzymes in the body. When body builders work out, their protein stores are depleted-and you need protein to build more lean muscle. It also raises levels of growth hormone, speeds up your metabolism, increases your body's fat-burning abilities, and lowers insulin levels. There are several different types of protein supplements, including whey, glutamine, albumin, casein, and soy. In general, protein is considered a natural supplement and safe to take, and it's usually taken immediately after workouts in powder form.

Meal replacements. Meal replacement products include bars and powdered drink mixes. They are meant to replace a whole meal, and most include a combination of high protein, low fats, moderate carbohydrates, and vitamins and minerals. Because body builders must eat every three hours or so, meal replacements are valued for their ease and convenience as well as their nutritional benefits. In general, they have no serious health side effects.

Vitamins and minerals. Body builders take vitamin and mineral supplements for a variety of reasons. Supplements with zinc, Vitamin B, E, and C, magnesium, selenium, and niacin are believed to aid in muscle recovery and repair. Beta-carotene and other vitamins reduce free radicals in the body, while Vitamins E, C, and other anti-oxidants are believed to promote heart health. While there are side effects associated with taking some vitamins in high doses, in general they are safe when taken in moderation.

Thermometric supplements. Thermometric supplements are fat-burners that raise the body's core temperature, thus raising its metabolism and causing it to burn fat more quickly. Up until 2004, almost all supplements of this type contained caffeine, aspirin, and ephedrine. When the FDA banned ephedra supplements, manufacturers started adding replacements such as bitter orange, which contains synephrine-a chemical similar to ephedrine, and that also acts as a stimulant. There is no scientific evidence proving the effectiveness of this chemical in weight loss. But there are side effects, including increased nervousness, heart palpitations, and shaking. In general, taking more of these supplements only results in increased side effects-not increased weight loss.

Testosterone. In addition to defining male sex characteristics, testosterone helps the body build muscle and burn fat. Men's testosterone levels peak in the teens, and drop as the body ages. Because of this, many older body builders seek to maintain their testosterone levels by taking supplements. There are many supplements on the market made from plants, vitamins, and synthetic chemicals that claim to boost testosterone levels, although proof of these claims is sketchy. There are serious side effects to taking too much testosterone, including hair loss, acne, shrinkage of the genitals, and changes in voice. In general, teenagers are advised not to take testosterone supplements, as their bodies already produce high levels of the hormone.

Human growth hormone (HGH). Human growth hormone raises your energy levels and metabolic rate, giving you more energy and allowing your body to burn fat at a higher rate. It lessens fatigue, strengthens ligaments and joints, and encourages the growth of lean muscle mass. It's also less easily detected than other hormone supplements. Side effects can include a distended belly if you take the drug too frequently; abnormal growth of bone and internal organs; increased risk of diabetes; atherosclerosis and high blood pressure; headaches and muscle pain; and bloating and swelling in the arms and legs.

Anabolic steroids. Anabolic steroids have been used for years in body building and in many other sports to build muscle beyond what the human body is capable of building on its own. Steroids are powerful performance-enhancing drugs that can have adverse effects on the body. Some of the side effects include altered sex characteristics-including breast growth, testicular shrinkage, and infertility in men; and facial hair and a lowered voice in women. Both sexes can experience increased risk of heart attack, high blood pressure, coronary artery disease, and liver damage. The use of these steroids is banned in all major sporting industries, including body building.

Some supplements are bad for your health when taken in high or even moderate doses, while others are relatively safe. In addition to safety, it's important to consider whether or not the supplement you're considering is backed by any scientific evidence that proves it's effective. If not, you may be wasting your money on a product that doesn't work. Do your research and talk to your trainer and doctor, and you should be able to find the combination of supplements that works for you.

About the author

Jean Lam is the webmaster of Body Building Resource which provides articles on weight training, nutrition and fitness, body building book and DVDs.