The hCG diet utilizes human chorionic gonadotropin, a hormone the placenta produces during pregnancy, to increase weight loss on a very low-calorie diet. Human chorionic gonadotropin has not been proven in clinical trials to increase weight loss beyond what you would lose with any low-calorie diet. Two forms of hCG are used for weight loss: an injectable form and a homeopathic remedy placed sublingually, under the tongue. The long-term effects of taking hCG on pregnancy have not been studied, but sublingual hCG does not appear in the blood and probably has no effect at all, although advocates disagree.
First used as a diet aid by British Dr. Albert Simeons in the 1950s, hCG was injected on a daily basis while patients followed a 500-calorie diet. This very-low calorie diet can have dangerous effects, although it causes rapid weight loss. Numerous studies showed that hCG did not have an added benefit, according to a meta-analysis of studies conducted by Dutch researchers and reported in the September 1995 issue of the "British Journal of Clinical Pharmacology." The effect of the drug on future pregnancies has not been tested. In men, injectable hCG can increase testosterone production, which may increase sperm production.
Sublingual hCG is a homeopathic remedy, meaning it contains extremely small amounts of diluted hCG. Since sublingual hCG doesn't appear in the blood in any detectable amount, according to Fred Bloem, M.D., it probably has no effect whatsoever on future pregnancies.
Human chorionic gonadotropin does interact with other hormones, when produces it naturally during pregnancy. Men who take large doses of injectable hCG can develop signs of excess estrogen production as excess testosterone converts to estrogen, with enlarged breasts as a side effect.This hormone, when injected, can also increase your risk of developing headaches, blood clots, fatigue, depression, dizziness and irritability.
Human chorionic gonadotropin is the same hormone measured in urine and serum pregnancy tests. Although the amount you take on the hCG diet is small, you could still register a positive result on a pregnancy test, even if not pregnant. This will not happen with sublingual hCG, which is undetectable in your blood. While your body produces hCG naturally during pregnancy without any effect on future pregnancies, the effects of hCG injections when you're not pregnant is not known. If you want to get pregnant in the future, talk to your doctor before starting hCG injections to lose weight.