As I've noted in the past , manufacturers of dietary supplements are not legally obligated to demonstrate either efficacy or safety of their products prior to reaching the store shelf. However, they are prohibited from using/including prescription medications in their products and from making health claims.
In this particular situation, hCG is a prescription medication which is typically used for female infertility purposes and off-label in hypogonadal men. For what it's worth, hCG is also recognized as a performance enhancing drug or substance w/guidelines recently promulgated by WADA (World Anti-Doping Agency) .
While I am not by any means an expert in homeopathy , the idea is that a substance is serially diluted to such a degree that none would be found/available but that the dilution would work its benefit via water's memory .
I suspect the FDA & FTC are upset since one can either claim the inclusion of hCG as a prescription product or disclaim its presence in a dietary supplement. But one shouldn't attempt to sell even "homeopathic" dilutions of prescription medications as supplements w/health claims.
Regardless, whether one chooses to search for "homeopathic" hCG or purchase prescription hCG from the myriad clinics sprouting up around the country, there is no credible data demonstrating any additional benefit of hCG in achieving weight loss beyond that from an extremely low calorie diet in isolation, ATW Simeon's writings notwithstanding . Such is the arcane legal battlefield that governs our health & science.