Behind only coronary and heart related illness, obesity is the second largest threat to the health and lives of Americans. The pharmaceutical industry has recently begun to investigate this health issue (known as obesity but despite the increase in research spending, a dieting wonder drug is yet to be found. The search continues for a drug that will trigger weight loss with no side-effects, but in the absence of a clear choice here you will find a review of the top diet pills available on the market today, complete with a review of their effectiveness and side-effects:

1) Hydroxycut. Based on th eECA stack (Effedrine, Caffein, Aspirin), Hydroxycut is a stimulant and appetite suppressant. Because it contains Effedrine it can have some serious side-effects: it affects your heart and can cause high blood pressure and rapid heartbeat. It is effective: there is clinical data to substantiate the manufacturer's claims of significant weight loss when used as directed. People with preexisting heart conditions should probably stay away from this product.

2) Hoodia. Hoodia is a natural, cactus based extract. It is an appetite suppressant, and one unreleased trial in 18 individuals concluded that those participants who took a recommended dose of a hoodia based product reduced their food intake by 1000 calories per day compared to a placebo group. Despite its popularity there are no studies to indicate that Hoodia is safe and effective in pill form. This is currently a very popular diet pill. Be careful when purchasing: an independent study estimates that eighty percent of hoodia products on the market are either counterfeit or contaminated.

3) Orovo. Orovo is sold as a short term detoxifier, and makes further claims to weight loss, skin rejuvenation energy booster and appetite suppressant. It is designed to be taken for seven consecutive days, with seven days off in between dosage. It is made of natural ingredients. While no clinical studies conclude that Orovo is safe and effective, there is a significant body of testimonial data to indicate that it does indeed enhance weight loss when taken in conjunction with a healthy diet.

4) Nuphedragen. These pills are stimulants and appetite suppressants. They contain Caffeine, Synephrin, Phenylethylamine and Chocamine (a proprietary extract of the cocoa plant). While the benefits of caffeine for weight loss are well documented, none of the other active ingredients in this formula have a body of clinical evidence validating their usefulness in weight loss.

5) Noxycut. Designed for men, Noxycut contains ingredients to increase testosterone levels as well as the fat burners synephrine, guggulsterones, yohimbe, caffeine and cinnamon. It is an appetite suppressant and claims to enhance the development of muscle tissue when combined with an appropriate workout routine. As with most diet pills that are appetite suppressants and contain caffeine, consumers with a history of heart disease should be careful and seek medical advice before taking this product.

6) Curvatrim. No Clinical evidence exists to support the manufacturer's claims that this product will simultaneously reduce fat, enhance breasts and clear up acne. It contains several effective ingredients, primarily diuretic in nature (such as caffeine) but the manufacturer does not disclose the amount of the ingredients contained: it's a "proprietary blend". Shown to be effective in some testimonials, it works primarily by reducing water weight and suppressing appetite.

7) 72 Hour Slimming Pill. This product is sold as a body detoxifying regimen designed to help you lose 6-15 pounds in three days. A review of the contents reveals that it contains a number of powerful diuretic compounds. Diuretics cause you to lose water weight, so while the product will indeed help you "lose weight", it's only water that you're losing, and you're going to gain it back quickly.

8) Caralluma Burn. This is an all-natural herbal appetite suppressant. Caralluma Burn is the right product for you if your appetite has been your downfall in the past. The formulation is caffeine free, and so won't give you the jittery feeling that most appetite suppressants do; the ingredients are all natural. Shown to be effective in clinical studies.

9) alli Weight Loss Pill. This is the only FDA approved weight loss product available without prescription. It blocks fat absorption. alli is sold bundled with an individually tailored support plan complete with telephone and online support to help you achieve gradual and healthy weight loss. Clinical trial data indicates that alli can help you gradually lose 50% more weight, and keep it off, than you would without a weight loss supplement.

10) Dietrine Carb Blocker. Preliminary and clinical studies indicate that this product reduces the absorption of carbohydrate calories, so the carbs that you eat pass through your system and are eliminated. No known side-effects or interactions with other herbal medications, and 100% natural.