Gonadorelin / hCG

What are gonadorelin and hCG?

The reproductive axis has three steps: the hypothalamus secretes GnRH, GnRH makes the pituitary release LH and FSH, and these stimulate the testes and ovaries. Gonadorelin is a synthetic copy of GnRH, the first step of this chain; gonadorelin acetate produced according to the European Pharmacopoeia has the same structure as the natural hormone. Under physiological conditions, GnRH is released every 60–120 minutes in short pulses of about one minute each. According to the SmPC, repeated administration, dose escalation, or continuous infusion reversibly suppresses gonadotropin secretion; this is called the “paradoxical antifertility effect.” ^[2]

hCG (human chorionic gonadotropin) acts at the lower step of the chain. It is secreted by the placenta in pregnancy and, as a drug, is obtained from the urine of pregnant women; its biological effect resembles the pituitary’s LH, but its half-life and duration of action are longer. In men it stimulates Leydig cells in the testis to increase testosterone production, and in women it increases estradiol and progesterone production. ^[3] Choriogonadotropin alfa, produced with recombinant technology, is used for the same purpose. ^[4]

Kisspeptin, which stimulates a step above this axis, is not licensed and is covered in a separate guide.

Detailed guideKisspeptin-10: evidence, risks, and legal status→

Which products are licensed in Türkiye?

The situation on the October 16, 2026 TİTCK Licensed Human Medicinal Products List is as follows: ^[1]

The list also includes other gonadotropin and pituitary hormone products such as oxytocin and menotropin; these are not the subject of this guide. ^[1]

What is gonadorelin used for?

The SmPC of the gonadorelin product in Türkiye states that the product is for diagnostic purposes only. A single dose is used to distinguish a disorder originating in the ovary or testis (peripheral) from one originating in the hypothalamus or pituitary (central). Repeated doses or infusion serve to distinguish whether a disorder arises from the pituitary or the hypothalamus in conditions such as hypothalamic amenorrhea and hypogonadotropic hypogonadism due to GnRH deficiency. ^[2]

According to the SmPC, gonadorelin is contraindicated in pregnancy and breastfeeding; it is used with caution in patients with pituitary adenoma because pituitary hemorrhage (apoplexy) has been reported. Anaphylactic reactions and injection site reactions are among the uncommon side effects, and anaphylactic shock is counted as very rare. Exceeding the recommended maximum dose can cause transient suppression of pituitary function. ^[2]

In the US, Factrel, containing gonadorelin hydrochloride, was approved on September 30, 1982 as a new molecular entity; in the Drugs@FDA record, the marketing status of its three presentations appears as “Discontinued.” ^[12]

What is hCG used for?

According to the SmPC, urine-derived hCG is indicated in situations where gonadal function needs to be activated, and its success depends on the functional capacity of the gonads: ^[3]

• In women: In functional infertility states such as primary amenorrhea, long-standing secondary amenorrhea, and chronic anovulation, to trigger ovulation after FSH or menotropin treatment; to prepare follicles for collection in assisted reproduction techniques such as IVF; infertility due to luteal phase insufficiency.
• In children and men: Undescended testis (cryptorchidism), hypogonadotropic hypogonadism, and delayed puberty. The SmPC states that in hypogonadotropic hypogonadism, treatment together with menotropin stimulates sperm production and improves fertility.

The SmPC of the recombinant product is narrower: triggering final follicle maturation in IVF treatment and triggering ovulation in women with absent or infrequent ovulation. The same SmPC states that there is no clinical experience in male-related conditions and that the product is not indicated in them. ^[4]

hCG in IVF and ovulation treatment

hCG is routinely used in IVF treatment to trigger final egg maturation. The 2014 Cochrane review examined 17 RCTs (1,847 women) comparing a GnRH agonist with hCG for this purpose. In fresh cycles with the woman’s own eggs, the GnRH agonist was associated with a lower live birth rate than hCG (OR 0.47, 95% CI 0.31–0.70; 5 RCTs, 532 women; moderate-quality evidence). In contrast, mild, moderate, or severe ovarian hyperstimulation syndrome (OHSS) was less frequent with the GnRH agonist (OR 0.15, 95% CI 0.05–0.47; 8 RCTs, 989 women; moderate-quality evidence). According to the authors, agonist triggering prevents OHSS but at the cost of lower live birth in the fresh cycle; the agonist may be useful in women who avoid fresh transfer or donate eggs. ^[5]

According to the SmPC, excessive ovarian stimulation can develop in 5–6% of patients treated with gonadotropins, mostly within 7–10 days after hCG; the risk is particularly high in polycystic ovary syndrome. ^[3] The SmPC of the recombinant product states that, very rarely, severe OHSS can be accompanied by clot events such as ovarian torsion, pulmonary embolism, stroke, or heart attack. ^[4]

Hypogonadism and undescended testis

hCG’s licensed use in men is based on diagnoses such as hypogonadotropic hypogonadism, in which pituitary LH secretion is insufficient, and delayed puberty; these diagnoses are made by a specialist physician’s tests. ^[3]

Undescended testis appears as an indication in the SmPC, and the SmPC notes that the chance of success is low if there is a congenital testicular lesion or anatomical obstruction. ^[3] The American Urological Association (AUA) 2014 guideline, based on 704 articles published between 1980 and 2013, by contrast, does not recommend hormone treatment and states that the most successful method for placing the testis in the scrotum is surgery (orchiopexy). ^[6]

Weight loss with hCG: what did FDA say?

The “hCG diet” (Simeons method) is a weight-loss method that combines hCG with a very low-calorie diet. A 1995 meta-analysis scored the 8 controlled and 16 uncontrolled studies examining this method by methodological quality. Scores ranged from 16 to 73 out of 100; of the 12 studies (all controlled) scoring 50 or above, only one found hCG beneficial. The authors concluded that there is no scientific evidence that hCG is effective in the treatment of obesity: it does not produce weight loss or change in fat distribution, does not reduce hunger, and does not produce a feeling of well-being. ^[7]

On December 6, 2011, FDA and the Federal Trade Commission (FTC) announced that they had sent seven joint warning letters to companies selling nonprescription hCG drops, pellets, and sprays labeled “homeopathic” for weight loss. According to the release, no hCG product is approved for weight loss, and there is no substantial evidence that hCG provides more weight loss than the recommended calorie restriction. ^[8] FDA’s question-and-answer page adds that the very low-calorie diet recommended alongside these products increases the risk of gallstones, electrolyte imbalance, and cardiac rhythm disturbances and should be followed only under medical supervision; at that date, all drug products claiming to contain “homeopathic hCG” were being marketed illegally. According to the same page, FDA has received reports of serious side effects associated with hCG injections used for weight loss, including pulmonary embolism, depression, cerebrovascular problems, cardiac arrest, and death; the page gives no causality assessment for these reports. ^[9]

The SmPC in Türkiye points the same way: there are no data showing that hCG has a role in fat metabolism, fat tissue distribution, or appetite, and the product has no indication related to weight control. ^[3]

Post-steroid therapy (PCT) and hCG

Anabolic steroids suppress the body’s own testosterone production through negative feedback. Some people who use steroids use drug combinations called “post-cycle therapy” (PCT) after the cycle ends to “recover” the hormone axis; the most common of these are estrogen receptor modulators, hCG, and aromatase inhibitors. ^[10]

The 2026 review writes the following about this practice: ^[10]

• Although PCT is embedded in steroid-use culture, it appears in no official medical guideline and is largely unsupported by controlled clinical evidence.
• High-dose use of hCG is common among users; however, because hCG can reduce the pituitary’s gonadotropin secretion, it may work against the goal of spontaneous recovery of the axis.
• Most of the products come from underground laboratories of uncertain quality.
• The existing literature does not support a clear benefit of PCT for long-term recovery of the axis or for low-testosterone symptoms; limited observational data suggest that short-term recovery might be accelerated. From an academic perspective, the most rational approach is monitoring, knowing that most men recover spontaneously.
• The review also reports a third, “pragmatic” view: that a short treatment might be considered in selected people with marked complaints or a risk of returning to steroid use, but that this is not supported by strong clinical evidence.

The study the review cites as “one of the more informative datasets” is a two-center retrospective cohort covering 79 men; the authors are from institutions in London, Ankara, and Milan. Men who had used steroids for at most 6 months and whose hormone and semen values were normal beforehand were followed in no-treatment, clomiphene-only, or clomiphene-plus-hCG groups. Hormones returned to normal in all groups at month 6; they recovered earlier in those who received drugs. At month 12, the normal semen rate was 87.5% in the clomiphene+hCG group, 69.2% in the clomiphene group, and 58.6% in the no-treatment group. The study is not randomized, and the authors emphasize that spontaneous recovery occurred in 6–12 months and that randomized studies are needed. ^[11]

A similar limit applies to gonadorelin: according to the SmPC, when given continuously or repeatedly at high doses, it suppresses gonadotropin secretion instead of increasing it. ^[2]

What are the risks?

The main risks listed in the hCG SmPC are as follows: ^[3]

• Contraindications: In men, androgen-dependent tumors such as prostate or breast cancer, and infertility not associated with hypogonadotropic hypogonadism; in women, pregnancy, ovarian, endometrial (uterine lining), and breast cancer, and uterine bleeding of unknown cause; in both sexes, hyperprolactinemia, pituitary or hypothalamic tumor, and untreated thyroid or adrenal hormone disorders.
• Clot risk: In patients with obesity, a family history of thrombosis, or smoking, the risk of venous and arterial blockage during or after gonadotropin treatment is higher.
• In men and children: In prepubertal children, an overdose can lead to early puberty and cessation of growth; an overdose lasting a few days can in some cases trigger breast enlargement (gynecomastia) in men that may be resistant to treatment. Fluid retention and edema have also been reported.

These risks are written for conditions in which the product is used under physician supervision and with an appropriate diagnosis. The PCT review writes that, with the drug groups used after steroids (estrogen receptor modulators, aromatase inhibitors, and hCG), side effects ranging from sexual dysfunction, mood changes, and joint pain to eye, liver, and cardiovascular complications have been reported, and that some of these overlap with the symptoms PCT aims to relieve. ^[10]

General peptide side effects and injection risks are covered in a separate guide: Peptide side effects

FDA, WADA, and Türkiye: what is the legal status?

United States

In the US, hCG is a drug approved in some cases of female infertility and in hormone treatment in men, given only by injection and by prescription; no hCG product is approved for weight loss. ^[9] Factrel, containing gonadorelin, is recorded as discontinued. ^[12]

Sport (WADA)

In WADA’s list valid from January 1, 2026, chorionic gonadotropin (CG), LH, GnRH including gonadorelin and its agonist analogs, and kisspeptin appear under S2.2.1 “peptides that stimulate testosterone in males.” Substances in class S2 are prohibited at all times, in and out of competition, and none is a “specified substance.” The prohibition definition is limited to males. ^[13]

Türkiye

Gonadorelin and hCG are licensed drugs on the TİTCK list; the license of the Pregnyl presentations is suspended. ^[1] Licensed drugs are used within the pharmacy and physician chain. Article 19 of Law No. 1262 on Pharmaceutical and Medicinal Preparations (İspençiyari ve Tıbbi Müstahzarlar Kanunu) punishes with imprisonment of one to five years those who manufacture unlicensed preparations and those who knowingly sell, offer for sale, or have them sold; importing preparations made abroad without a license for commercial purposes counts as smuggling. ^[14]

The general legal framework for peptides: Are peptides legal?

Evidence table: claim, population, and limits

Limits of this guide

This page summarizes the official product information, guidelines, meta-analyses, and official institution statements on gonadorelin and hCG. It gives no dose, cycle, preparation, administration technique, or product-sourcing information. Infertility, hypogonadism, and hormone disorders after steroid use are conditions that must be evaluated with laboratory tests and monitored by a physician.