WHAT IS HCG

Human Chorionic Gonadotropin (hCG) is a potent hormone naturally produced by the syncytiotrophoblast cells of the placenta immediately following embryo implantation. HCG is the first pregnancy hormone the placenta makes after conception.

You can think of hCG as the first hormone that supports early pregnancy—then, it calls in other hormones to help. It plays an important role in telling the rest of your body that you are pregnant.

Primary Biological Function

The primary biological function of hCG is to maintain the corpus luteum in the ovary. This, in turn, ensures the continued production of Progesterone and Estrogen necessary to sustain early pregnancy.

• Progesterone: This hormone supports pregnancy by thickening the uterine lining and keeping the uterus relaxed.

• Estrogen: This hormone helps with fetal organ development, increases blood flow to the placenta, and helps prepare the body for labor.

HCG tells your body to stop menstruating, and then signals your body to produce these hormones, Progesterone and Estrogen, which are necessary for pregnancy and fetal development.

WHAT DOES HCG DO?

HCG is the first pregnancy hormone the placenta makes after a fertilized egg attaches to the uterine wall. Its main role is to maintain the corpus luteum, a temporary endocrine gland in the ovary.

• Progesterone Production: The corpus luteum produces high levels of progesterone, which is essential for maintaining the uterine lining and supporting the developing embryo until the placenta takes over hormone production.

• Pregnancy Test Detection: The presence of hCG in the blood or urine is the signal detected by home pregnancy tests.

Stimulating Hormone Production (LH Mimic)

In medical and therapeutic contexts, injected hCG mimics the action of LH, a natural pituitary hormone.

FDA-Approved Clinical Uses

• Female Infertility (Ovulation Induction): Used to trigger the final maturation of the egg and induce ovulation (the LH surge) in women undergoing fertility treatments (IVF or IUI).

• Male Hypogonadism/Infertility: Used in men with hypogonadotropic hypogonadism (HH) to stimulate the Leydig cells in the testes to produce endogenous testosterone and maintain spermatogenesis.

• Cryptorchidism: Used to promote testicular descent in prepubertal boys where no anatomical obstruction exists.

Off Label Research Use (Male TRT)

• Fertility Preservation during TRT: When men take exogenous Testosterone Replacement Therapy (TRT), the Hypothalamic Pituitary Gonadal (HPG) axis is suppressed, halting natural LH and FSH production, leading to testicular atrophy and infertility.

• HCG is often used alongside TRT (off-label) to mimic LH and stimulate the Leydig cells, thus preserving testicular size and function.

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  Other Minor Functions

  • Fetal Development: It plays a role in fetal growth and the development of sex organs in male fetuses.

  • Undescended Testicles: In young boys, it is used to attempt to stimulate the descent of the testicles.

BENEFITS/ CLINICAL TRIALS

Prescription-grade hCG is an FDA-approved drug for specific medical conditions related to fertility and hormone management.

FDA-Approved Clinical Uses

HCG functions by mimicking Luteinizing Hormone (LH), stimulating the gonads to produce necessary hormones.

• Ovulation Induction (Women): HCG is used to reliably trigger the release of a mature egg from the ovary (ovulation). This is critical for fertility success, especially as part of assisted reproductive technologies like in vitro fertilization (IVF).

• Male Infertility/Hypogonadism: In men, hCG stimulates the testes to produce endogenous testosterone and sperm. It is used to treat low sperm count, hypogonadotropic hypogonadism (HH), and other hypogonadal symptoms (low libido, low energy).

• Fertility Maintenance (Men): It is also used in conjunction with Testosterone Replacement Therapy (TRT) to prevent testicular atrophy and maintain fertility, as TRT typically suppresses the body's natural hormone signals.

• Undescended Testicles (Prepubertal Boys): HCG can be used to treat prepubertal cryptorchidism (undescended testicles) not caused by an anatomical obstruction.

Documented Benefits

 Studies have documented that, in an FDA-approved context, hCG is safe and efficacious in:

• Reliably triggering ovulation in women prepared with gonadotropins.

• Significantly and dose-dependently increasing serum Testosterone and intratesticular Testosterone (ITT) concentrations in men with HH.

• Improving hypogonadal symptoms in men, even those with baseline Testosterone levels above the traditional threshold.

Weight Loss Claims and Warnings

• FDA Warning: The FDA has issued strong warnings against the use of hCG for weight loss.

• Lack of Efficacy: Extensive research, including meta-analyses, has concluded that hCG has NO KNOWN EFFECT on fat mobilization, appetite, or distribution of fat.

• Danger: Any observed weight loss from the "hCG diet" is solely attributed to the severe caloric restriction (500 to 800 calories per day) that accompanies the protocol.

SIDE EFFECTS

hCG administration carries risks due to its powerful hormonal action and potential for rapid changes in sex steroid levels. Side effects depend on the dosage and individual sensitivity.

Common Side Effects (Men and Women)

These are generally hormone-related or local reactions:

• Hormone-related: Headache, fatigue, mood changes (irritability, depression, restlessness), mild swelling (edema), and nausea or vomiting.

• Local Reactions: Pain, bruising, or irritation at the injection site.

• Sex-Specific: Breast tenderness or enlargement (gynecomastia in men), and swelling of the testes or penis in men.

Serious Side Effects (Primarily Women)

Serious adverse risks, though rare, are often related to the hormonal potency of hCG:

• Ovarian Hyperstimulation Syndrome (OHSS): This is the principal serious adverse reaction in women, and it can be life-threatening. It involves sudden ovarian enlargement, severe pelvic pain, ascites (fluid in the abdomen), rapid weight gain, and shortness of breath.

• Thromboembolic Events (Blood Clots): There is an increased risk of blood clots (for example: stroke, pulmonary embolism), both in association with and separate from OHSS. Signs include pain or swelling in the leg, shortness of breath, chest pain, or slurred speech.

IS HCG SAFE?

The primary safety concerns surrounding hCG stem from its use in unapproved contexts, particularly the "hCG diet" for weight loss.

Weight Loss: Unsafe and Unapproved Use

• Not FDA-Approved for Weight Loss: The FDA has explicitly stated that hCG is not approved as a weight-loss treatment. Scientific evidence does not support claims that hCG is effective for weight loss beyond the severe calorie restriction (usually 500 calories per day) that accompanies the diet.

• Unregulated Products: Over-the-counter hCG products (drops, sprays, pellets) sold online and in stores are unapproved new drugs, contain unknown ingredients, and are illegally marketed.

• Serious Health Risks: HCG is NOT SAFE for the unapproved purpose of weight loss. The weight loss protocols accompanying hCG supplements (VLCDs) are dangerous and put users at risk of severe malnutrition, electrolyte imbalance, gallstones, and abnormal heart rhythms. The use of hCG for weight loss has been linked to reports of serious adverse events, including pulmonary embolism, depression, cardiac arrest, and death.

Safety Takeaway

Prescription-grade hCG is an FDA-approved drug for specific indications related to fertility and hormone management, and its safety is established for these clinical uses when administered under strict medical monitoring.

Use outside of a regulated medical context for approved indications is strongly advised against.

DOSAGE

Human Chorionic Gonadotropin (hCG) is a hormone that is used in medicine for various purposes, primarily related to fertility treatments and hormone imbalances.  It is measured in International Units (IU) and requires precise dosing and medical supervision.

The specific dosage and treatment regimen are highly individualized and depend on the medical condition being treated, as well as the patient's response.  Therefore, it is crucial that hCG treatment is prescribed and closely monitored by a licensed medical professional.

Administration Route

HCG is administered via injection, as oral forms are considered ineffective due to the molecule's high molecular weight. 

•  Administration: Typically administered via subcutaneous (SubQ) or intramuscular (IM) injection.

• Male/TRT: 500 to 1,500 IU: 2-3 times per week, followed by 500 to 1000 IU 2 times per week (3 weeks per phase)
• Female Ovulation: 5,000 to 10,000 IU: used once
• Weight Loss (not advised): 125 IU to 250 IU: administered daily until desired results are reached.

RECONSTITUTION

Applies to the following strengths: 10,000 units; recombinant 250 mcg; recombinant 250 mcg/0.5 mL.

Prescription HCG is supplied as a sterile lyophilized (freeze-dried) powder.

• Reconstitution Fluid: Must be reconstituted with the sterile solvent provided by the manufacturer (usually Bacteriostatic Water) to maintain sterility.

WHERE TO BUY HCG

Researchers should always vet their sources to ensure that a few key factors are present in their test subjects. With the rise in peptide popularity in recent years, many companies have created peptides that undergo little to no testing, quality standards, or regulations. As it is not regulated by the FDA, researchers must do their due diligence and look closely at the company's practices and standards. 

When selecting a supplier for HCG, focus on transparency and quality assurance, not customer testimonials:

1. Quality Documentation: A reputable supplier must provide:
   •  Certificate of Analysis (COA): This document must be recent (corresponding to the batch/lot number purchased) and demonstrate a minimum purity of >95% via High-Performance Liquid Chromatography (HPLC) testing.
   • Mass Spectrometry (MS) Data: The COA must include mass spectrometry (MS) confirmation to verify the compound’s exact molecular weight, confirming its chemical identity.
   • Contaminant Testing: Look for reports on heavy metals, microbial load, and solvent residues (e.g., residual trifluoroacetic acid, or TFA). The presence of these contaminants can severely compromise research and introduce unknown toxicity.
2. Vendor Verification and Transparency 

   • Specialization: Prioritize vendors who specialize in the manufacturing and distribution of peptides for academic and biotechnology research, rather than general supplement vendors.

   • Manufacturing Origin: Inquire about the source of the raw materials and the manufacturing protocols. Ideal suppliers adhere to strict quality control processes.

   • Handling & Storage: The supplier must provide clear documentation on the proper storage and handling procedures for the peptide to maintain its stability and integrity.

Conclusion on Procurement: Given the high risk of contamination, mislabeling, and legal ambiguity. The use of HCG outside of this defined research context poses unacceptable, unquantified risks to human health.

REFERENCES

• Network, the Healthline Medical. “Your Guide to Human Chorionic Gonadotropin (Hcg) Injections for Men.” Healthline, Healthline Media, 13 Oct. 2025, www.healthline.com/health/mens-health/hcg#:~:text=Human%20Chorionic%20Gonadotropin%20(hCG)%20Injections%20for%20Men,they%20can%20treat%20a%20type%20of%20hypogonadism
• “Human Chorionic Gonadotropin (HCG) Injectable Uses, Side Effects & Warnings.” Drugs.Com, www.drugs.com/mtm/human-chorionic-gonadotropin-hcg-injectable.html#:~:text=HCG%20can%20cause%20serious%20side,one%20side%20of%20the%20body. Accessed 15 Nov. 2025. 
• Commissioner, Office of the. “Avoid Dangerous HCG Diet Products.” U.S. Food and Drug Administration, FDA, www.fda.gov/consumers/consumer-updates/avoid-dangerous-hcg-diet-products. Accessed 15 Nov. 2025. 
• Palsdottir, Hrefna. “Should You Try the Hcg Diet?” Healthline, Healthline Media, 19 Apr. 2023, www.healthline.com/nutrition/hcg-diet-101#:~:text=Safety%20and%20side%20effects,fatigue. 
• “Chorionic Gonadotropin (Hcg) Dosage Guide + Max Dose, Adjustments.” Drugs.Com, www.drugs.com/dosage/chorionic-gonadotropin-hcg.html. Accessed 17 Nov. 2025. 
• “HCG-Beta (123-145).” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, pubchem.ncbi.nlm.nih.gov/compound/HCG-beta-_123-145#section=2D-Structure\. Accessed 21 Nov. 2025. 

• The National Center for Biotechnology Information (NCBI) - StatPearls. "Physiology, Chorionic Gonadotropin."

• Frontiers in Immunology. "Human Chorionic Gonadotrophin: New Pleiotropic Functions for an $\text{Old}$ Hormone During Pregnancy."

• U.S. Food and Drug Administration ($\text{FDA}$) - Drug Labeling. "CHORIONIC GONADOTROPIN FOR INJECTION."

• PubMed Central (PMC). "Human Chorionic Gonadotropin monotherapy for the treatment of hypogonadal symptoms in men with total testosterone $> 300 \text{ ng}/\text{dL}$."

• WebMD. "$\text{hCG}$ (Human Chorionic Gonadotropin) for Weight Loss: Injections and Drops."

• Cleveland Clinic. "$\text{HCG}$ Diet for Weight Loss: Is It Safe?"

• HTX Urology. "Understanding Men's Hormone Therapy: Do You Need HCG with TRT?"