hCG is the acronym for Human Chorionic Gonadotropin, a substance produced by the placenta during pregnancy in huge amounts. It was discovered by Ascheim and Zondek in the urine of pregnant women, back as 1927.

After its discovery, scientists tried to find a name for this substance, and when they observed that the administration of hCG helped to provoke ovulation in experimentation animals, they named their discovery Gonadotropin, that means it has an action on gonads (testicles or ovaries) and Chorionic because later it was found was produced by the Chorium of the placenta.

hCG is one of the few drugs of natural origin that still remain in the current Pharmacopoeia. Secreted by the placenta, the presence of hCG in the urine of pregnant women was first reported by Ascheim and Zondek in 1927. Since then, thousands of scientific articles have been published about the effect of hCG on gonads (testicles or ovaries), but comparatively a small number of these have investigated its vast therapeutic potential on diseases ranging from Kaposi sarcoma, to asthma, psychoses, artheriopaties, thalassemia, osteopenia, glaucoma, and cancer.

Large quantities of hCG are secreted by the placenta during pregnancy, invalidating claims of cancer or hirsutism (disproportionate hair growth) as side effects of HCG, as no clinical records exist of pregnant women being more susceptible to these diseases.

Research done by Dr. Daniel Belluscio at the Oral hCG Research Center has determined that the use of hCG for obesity treatment meets patients' expectations for a safe and effective weight loss program that is easy to follow and can improve their quality of life, without negative side effects or contraindications.

- See ‘The hCG (Human Choriogonadotropin) method for the treatment of obesity: Overcoming the "test of time"’ for a complete description of the pharmacological nature of hCG.