The HCG (human chorionic gonadotropin) diet sets off two big red flags. First, it caps your intake at 500 calories a day when experts warn that the typical woman needs 1,600 to 2,400 calories daily, and the typical man needs 2,000 to 3,000 calories to maintain a healthy weight. (If you follow a diet containing less than 1,200 calories, you should do so only under a doctor's supervision.) Experts say such a low calorie intake can cause side effects such as gallstones, bone and muscle loss, electrolyte imbalances and heart arrhythmia. The diet isn't only calorie-restricted; you must also eat only organic meats, vegetables and fish.
Second, daily injections of HCG are supposed to curb your appetite so you can better tolerate living each day on what one source calls "the energy equivalent of a turkey sandwich." HCG is approved by the FDA for use only by prescription and to treat very limited conditions, mainly fertility; HCG is not approved for over-the-counter sale, or for treating overweight or obesity.
The HCG injections come with additional risks such as decreased sperm production, male breast enlargement, headaches, long-term breast cancer risk, fatigue and blood clots. One expert calls the diet "utter and dangerous nonsense," and warns that it can even kill you. Another says this sort of extreme calorie restriction isn't sustainable, and doesn't create the kind of lifestyle change that prevents dieters from regaining the weight. Some health food stores sell supplements labeled as homeopathic HCG, but the FDA says their sales are illegal (as are some of the marketing claims supplement manufacturers make) because HCG isn't approved for over-the-counter use.
We found no recent medical studies about using HCG for weight loss, but older studies published in the British Journal of Clinical Pharmacology and the South African Medical Journal indicate no scientific basis for using HCG as a weight-loss supplement. There's a thorough accounting of which foods are allowed at RD411.com, and a number of other recaps and expert opinions from sources like MayoClinic.com. The only positive review we found was published in Marie Claire, where one woman shares her weight-loss experience.
1. British Journal of Clinical Pharmacology
This meta-analysis reviews eight controlled and 16 uncontrolled trials measuring HCG's weight-loss efficacy. Researchers say most of the studies were of "poor methodological quality," there's no scientific evidence to indicate HCG's usefulness in the treatment of obesity, and it doesn't do any of the things it's often marketed for, including reducing hunger and redistributing fat.
Review: The Effect of Human Chorionic Gonadoptropin (HCG) in the Treatment of Obesity by Means of the Simeons Therapy: a Criteria-Based Meta-Analysis, G.K. Lijesen, et al., Sept. 1995
2. South African Medical Journal
Forty obese women are placed on a calorie-restricted diet and given injections of either HCG or a saline placebo. At the end of six weeks, the HCG group shows no advantage (or increased weight loss or body circumference) over the placebo group.
Review: Human Chorionic Gonadotrophin and Weight Loss. A Double-Blind, Placebo-Controlled Trial, B. Bosch, et al., Feb. 17, 1990
3. U.S. Food and Drug Administration
The FDA discusses concerns about unproven and illegal HCG products and misleading marketing claims. There are links to other FDA articles about HCG, including a drug safety podcast.
Review: Fraudulent HCG Products for Weight Loss, FDA Officials, Dec. 6, 2011
Experts give a thorough accounting of which foods are allowed according to both "accepted" book versions, the original by Dr. A.T.W. Simeon and a 2007 follow-up by Kevin Trudeau, who has been accused of fraud and misrepresentation. Included is a long list of reported side effects from using HCG (plus possible side effects of improperly injecting yourself).
Review: Human Chorionic Gonadotropin (hCG) Diet, Nutritionists at RD411.com, April 2010
5. ABC News
ABC asks a panel of three health experts from prominent universities to evaluate several weight-loss plans, including the HCG diet. One calls it "utter and dangerous nonsense," and warns that its severe calorie restriction could even be lethal.
Review: Baby Food, CarbLovers, HCG Diets and More: Which Fad Diets Work?, ABC News Medical Unit, July 22, 2011
6. Mayo Clinic
A registered dietitian says calorie restriction, not HCG, causes weight loss on this diet. She adds that it's unknown whether HCG is safe for this use or not, warns of potential side effects from the diet, and cautions that HCG products sold on the Internet "might not be what they say they are."
Review: Does the HCG Diet Work – And Is it Safe?, Jennifer K. Nelson, RD, LD, June 26, 2010
7. U.S. News & World Report
The author reviews general information about HCG and interviews a medical professor about its effects. She also relates the story of a fit, active soccer referee who tried the HCG diet and saw negative results.
Review: HCG Diet Dangers: Is Fast Weight Loss Worth the Risk?, Angela Haupt, March 14, 2011
8. Marie Claire
One woman relates her positive experience with the HCG diet (she self-injected HCG once a day for 45 days). She says she lost 25 pounds and, as of the article's press date, has kept it off.
Review: The Controversial Diet That Really Works, Alison Edmond, as told to Erin Flaherty, Jan. 27, 2011
9. Shape magazine
The author recaps a few quick facts about this diet, including its lack of FDA approval, the lack of research about its efficacy for weight loss and potential side effects.
Review: 5 Things You Need to Know About the HCG Diet, Jennipher Walters
10. ABC News
This article covers the developing controversy about so-called homeopathic HCG products available over the counter. (Normally, HCG is available only by prescription, in an injectable form, for treating infertility and some hormone imbalances.)
Review: FDA, FTC Crack Down on Illegal HCG Weight Loss Products, Lara Salahi, Dec. 6, 2011