As an endocrinologist, I probably should know quite a bit about all the various hormones out there. But, somehow I fell down on the job. It is only in the past week or so that I learned about the hCG/weight loss craze. It’s all over the news and the internet. The other night I saw 3 hCG ads on TV. What is this all about?
Human Chorionic Gonadotropin or hCG for short, is a glycoprotein hormone that is produced mainly in the placenta (the fetus and various tumors can also make the hormone). As the name implies, the hormone stimulates the gonads, akin to the pituitary gonadotropins, luteinizing hormone (LH) and follicule-stimulating hormone (FSH). It was discovered in 1919 and within a few years it was found to be useful as a pregnancy test. The “A-Z test” (named for Asheim and Zondek) was based on the fact that the urine of pregnant women promoted ovarian follicular development, ovulation, and formation of the corpus luteum (the “scar” in the ovary formed after ovulation and the site of progesterone production). In the 1930s it was established that hCG was a placental hormone. In the 1940, the hormone was purified. We now know that the hormone consists of 2 subunits, alpha and beta. The alpha subunit is virtually identical to several other pituitary hormone alpha subunits including LH and FSH and thyroid-stimulating hormone (TSH). In addition, the beta subunit of hCG is very similar to that of LH and, as we will discuss, hCG works a lot like LH.
What does hCG do?
Although the function of hCG in pregnancy is not completely understood, most experts believe the hormone is critical to maintain the function of the corpus luteum ( i.e., adequate progesterone production) during early pregnancy. The hormone level in the blood (and urine) rises rapidly in early pregnancy, reaches a peak at about 10-12 weeks and then gradually declines to a steady but low level throughout the rest of pregnancy. Not surprisingly, the hormone level is higher in pregnancies with multiple fetuses. Levels are very high in cases of maternal isoimmunization (i.e., Rh factor disease) and in women with hydatidiform mole or choriocarcinoma.
Clinically, other than its use as a pregnancy test, hCG has been used mostly as a fertility drug, in women to stimulate ovulation, and in men, to stimulate sperm production. The hormone is also used by pediatric endocrinologists and urologists in an effort to coax undescended testes into the scrotum. I do not think it is used much these days for this purpose
The use of hCG for weight reduction
The idea of using hCG as a diet drug seems to have come from the work of a British endocrinologist named Albert Simeons. Don’t ask me why, but Simeons studied the use of hCG injections for weight reduction in pregnant women and overweight boys in India. He found that treating these patients with extremely low-calorie diets (500 kcal/d) for several months at a time and low-dose hCG injections resulted in impressive weight loss that was mostly fat tissue, not lean body mass (i,e, muscle). Apparently, the idea caught on and for quite a number of years, hCG has been widely used (but below my radar) as a weight-loss drug. As best I can tell, there are no convincing scientific data to show any weight loss benefit from hCG (a very good reference on the subject is Lijesen GK et al: Br J Clin Pharmacol 1995;40:237-43). Various medical professional organizations have issued warnings about the ineffectiveness of hCG for weight loss.
Perhaps, the most interesting development has been the rapid rise in the popularity of oral hCG, so-called “homeopathic hCG.” This product comes in the form of drops and can be purchased from numerous sites on the internet. The sites typically consist of pages and pages of testimonials and how to purchase the product. I do not know if it is true, but an article in Wikipedia states that the U.S. Food and Drug Administration has deemed homeopathic hCG an illegal substance and it is not protected as a homeopathic drug. I am not aware of any credible scientific studies showing any health benefit from these oral products. One would not expect any benefit since “real” hCG is only biologically active when taken by injection. As you might expect, homeopathic hCG drops are very expensive, with typical treatment courses costing many hundreds of dollars.
What about hCG injections? There is no question that injected hCG is biologically active and has legitimate medical uses in the treatment of infertility. In men, hCG acts about like LH to stimulate testis testosterone production. In fact, hCG has been used by drug doping athletes to normalize testis size after they have taken high dose testosterone injections to enhance athletic performance; the testosterone injections inhibit LH secretion, resulting in shrinkage of the testes. In women, the effects of hCG are complex. The hormone can promote ovulation, and as discussed earlier, it can help support the corpus luteum and progesterone production. The hormone can also lead to increases in estrogen production by first stimulating synthesis of testosterone in the ovary which is then converted into estrogen by enzymes in the ovarian granulosa cells. Unfortunately, in some patients, hCG injections can result in the ovarian hyperstimulation syndrome in which very large increases in testosterone occur. The condition can be life-threatening with the development of massive edema and vascular thromboses. Many other hCG side effects have been reported. Of course, when used as fertility drug, hCG injections can greatly increase a woman’s chances of having a multiple pregnancy. Anyway, if hCG doesn’t really help promote weight loss, it is my opinion that the possible therapeutic risks (many) outweigh any possible benefits (none proven).
What is most amazing to me is that apparently many insurers will cover the cost of hCG injections for weight loss if prescribed by a physician . The hormone is marketed by several pharmaceutical companies (e.g., brand names include Chorex, Novarel, Pregnyl, and Profasi). Even without insurance coverage, the cost of injectable hCG is quite low, about $2.00/injection (a good summary of the costs and side effects can be found at eHow.com).
Who said our health care system is broken?
- FYI: Nice Review About Vitamin D
- An Addendum: Use Of Human Chorionic Gonadotropin (hCG) For Weight Loss