Also known as Human chorionic gonadotropin · Choriogonadotropin alfa · Ovidrel · Pregnyl · Novarel
A heterodimeric glycoprotein hormone — two different glycosylated subunits — that mimics the LH surge; the pregnancy hormone, also the subject of a debunked diet.
Human chorionic gonadotropin is the most structurally complex hormone in this catalog. It is not a single chain but a non-covalent heterodimer of two different subunits — a 92-amino-acid alpha subunit (shared with LH, FSH, and TSH) and a 145-amino-acid beta subunit that is specific to hCG — each heavily decorated with sugar chains. That glycosylation is not decoration: it is essential to the hormone’s long circulating half-life and biological activity, and it makes hCG a true glycoprotein biologic, roughly 36–40 kDa, that cannot be captured as a simple amino-acid formula.
hCG’s biology is defined by its architecture. The alpha subunit is common to the whole glycoprotein-hormone family (LH, FSH, TSH); specificity comes entirely from the beta subunit and the way the two fold together. Because the subunits are made and then assembled — and because the sugar chains are added by the producing cell — hCG is a genuine glycoprotein: recombinant versions (choriogonadotropin alfa) are made in mammalian (CHO) cells precisely so that human-like glycosylation can occur, while older products are purified from the urine of pregnant women. This is biology that bacterial synthesis cannot reproduce.
In medicine it is well established: it triggers ovulation in assisted reproduction, supports early-pregnancy progesterone, and is used in male hypogonadism and to preserve testicular function and fertility — including alongside testosterone therapy, where it keeps the testes signaled. It is also, famously, the hormone that pregnancy tests detect.
The drama is the HCG diet. In the 1950s a British physician, Albert Simeons, claimed hCG injections plus a 500-calorie diet caused targeted fat loss. The diet was repeatedly debunked — the weight loss comes from near-starvation, not the hormone — yet it resurfaces continually, and the FDA has explicitly warned that over-the-counter "homeopathic" hCG weight-loss products are illegal and ineffective. A second, quieter misunderstanding surrounds its use in performance and TRT communities. Both make hCG a clean example of a legitimate, well-characterized hormone whose public reputation is dominated by uses it was never validated for.
Acts as an agonist at the LH/CG receptor, reproducing the luteinizing-hormone signal: in women it triggers ovulation and sustains the corpus luteum’s progesterone; in men it stimulates Leydig-cell testosterone production. Its long half-life, conferred by glycosylation, lets a single dose mimic the natural LH surge.
Behind every vial of HCG is the same exacting pipeline every research peptide runs — but the chemistry plays out differently for this molecule. Here is how HCG, specifically, is brought into being.
On paper, HCG weighs in at roughly 36,700 daltons. Before a single bond is made, the target sequence, salt form, and purity threshold are written down as the contract the finished material must meet.
HCG is assembled by solid-phase peptide synthesis — the chain grows one protected residue at a time on resin, and what you fail to build cleanly here you pay to remove later.
The crude mixture — HCG plus its deletions and side products — is then separated on preparative HPLC, and where the cut is taken decides the difference between a genuinely pure peptide and a barely-passable one.
A real batch of HCG proves itself: identity confirmed by mass spectrometry against its ~36,700 Da, purity read directly off an analytical HPLC trace, water and counterion content measured. That batch-specific certificate of analysis is the only honest way to know what is actually in a vial of HCG — and a short, cold, accountable chain of custody is how that purity survives the trip to your bench.
hCG is either purified from the urine of pregnant women or, as choriogonadotropin alfa, produced recombinantly in mammalian (CHO) cells so that the essential glycosylation is human-like. Its molecular weight (~36–40 kDa) is approximate and varies with glycosylation, so it is not represented by a single molecular formula. Characterization includes subunit identity, glycan profiling, and bioassay potency — glycoprotein-grade analytics well beyond an HPLC purity number.
Don't judge a vial by its cake. A fluffy, good-looking lyophilized powder reflects bulking agents and freeze-drying parameters — not purity. Insist on a batch-specific certificate of analysis.
Recent clinical trials and publications mentioning Human chorionic gonadotropin, pulled automatically from ClinicalTrials.gov and PubMed and refreshed daily. Listings are unfiltered search results, not curated endorsements.
Human chorionic gonadotropin — a glycoprotein hormone made of two different glycosylated subunits that mimics luteinizing hormone. It triggers ovulation, supports early pregnancy, and stimulates testosterone in men. It is also the hormone pregnancy tests detect.
It is a two-subunit protein heavily modified with sugar chains that are essential to its half-life and activity. Recombinant hCG is made in mammalian cells so that human-like glycosylation can occur — something bacterial peptide synthesis cannot do.
No. The HCG diet has been repeatedly debunked — any weight loss comes from the extreme calorie restriction, not the hormone — and the FDA has warned that OTC homeopathic hCG weight-loss products are illegal and ineffective.
No — this is a research and educational reference. hCG is a prescription hormone with specific approved indications.