HCG (Human Chorionic Gonadotropin)

WHAT IT IS

Human chorionic gonadotropin is a glycoprotein hormone, not a small peptide, made of two subunits and produced naturally by the placenta during pregnancy. It shares a receptor with luteinizing hormone, which is why it can substitute for LH signaling in the testes or ovaries.

Pharmaceutical hCG is purified from the urine of pregnant women or manufactured recombinantly, and it has been used in reproductive medicine since the mid-twentieth century, well before it became a recognizable name in wellness and diet marketing.

It is a protein hormone with a long, well-documented clinical history for reproductive indications, and a separate, much more controversial history as a marketed weight-loss aid, which is not the same thing as an approved use.

APPROVED AND RESEARCHED USES

FDA-approved and clinically supported uses of hCG include:

• Inducing ovulation as part of infertility treatment in women
• Treating hypogonadotropic hypogonadism and stimulating testosterone production in men
• Managing certain cases of cryptorchidism (undescended testicles) in prepubertal boys
• Supporting spermatogenesis in men with pituitary-related infertility, often alongside FSH-containing medications

PROPOSED BIOLOGICAL MECHANISM

Because hCG binds and activates the LH receptor, it triggers the same downstream effects as a surge of natural LH, prompting the ovaries to release an egg or the testes to increase testosterone production.

In men, this LH-mimicking action is also why hCG has been studied alongside testosterone therapy, since it can help maintain testicular testosterone production and size, which exogenous testosterone alone tends to suppress.

hCG does not act on appetite, fat metabolism or thyroid signaling in a way that would plausibly explain a weight-loss effect, which is a separate and important point from its reproductive endocrinology role.

AREAS OF ONGOING INTEREST

• Optimal low-dose hCG protocols to preserve fertility during testosterone therapy
• Comparative outcomes of hCG versus gonadorelin for maintaining testicular function
• Use in assisted reproduction alongside other gonadotropins
• Continued public health efforts to curb its marketing for unapproved weight-loss use

WHAT THE EVIDENCE CURRENTLY SUGGESTS

For its approved fertility and hypogonadism indications, hCG has decades of clinical trial and real-world use behind it, making it one of the better-established hormone therapies discussed on this site.

For weight loss, the picture is different. Multiple controlled studies going back to the 1970s and beyond have failed to show that hCG produces fat loss beyond what a very low-calorie diet accomplishes on its own, and the appetite-suppressing claims associated with hCG diet products have not held up under controlled testing.

The FDA has been explicit and public about this distinction. FDA status: hCG is FDA-approved for specific fertility and hypogonadism indications, and the agency has stated plainly that hCG is not approved, or shown to be effective, for weight loss.