HCG Injections: Uses, Dosage, Side Effects & Complete Guide

✓ Medically reviewed by  ·  Last reviewed: May 2026

Morgan Ellis

Pharmacy Researcher · 8 years experience

Pharmacy researcher with 8 years reviewing clinical drug information, generic formulation equivalence, and international pharmaceutical standards. Focuses on patient-facing accuracy in medication education.

Human Chorionic Gonadotropin (HCG) is one of the most versatile hormones used in modern medicine — prescribed for female fertility treatments, male testosterone therapy, post-cycle therapy in bodybuilding, and even controversial weight-loss protocols. Whether you are a woman preparing for IVF, a man on testosterone replacement therapy trying to preserve fertility, or simply researching your options, understanding how HCG injections work, what doses are used, and what side effects to expect is essential before starting treatment.

This guide covers everything you need to know about HCG injections in 2026: the science behind the hormone, every major clinical use, detailed dosage tables, step-by-step administration instructions, side effects ranked by frequency, and a comparison of the HCG products available at MedsBase.

Last updated: April 10, 2026

What Is HCG (Human Chorionic Gonadotropin)?

Human Chorionic Gonadotropin — universally abbreviated as HCG — is a glycoprotein hormone naturally produced by the trophoblast cells of the placenta during pregnancy. It is the hormone detected by pregnancy tests: HCG levels rise rapidly after implantation, doubling roughly every 48 hours during the first trimester, and peaking at around 100,000 mIU/mL between weeks 8 and 11.

But HCG’s clinical significance extends far beyond pregnancy detection. The hormone shares a nearly identical molecular structure with Luteinizing Hormone (LH), the pituitary hormone that signals the gonads to produce sex hormones. Because HCG binds to the same LH receptors, it can be used therapeutically to mimic LH’s effects — triggering ovulation in women, and stimulating testosterone production in men.

Urinary-derived vs recombinant HCG

Pharmaceutical HCG comes in two forms:

• Urinary-derived HCG (uHCG): extracted and purified from the urine of pregnant women. This is the traditional form, used for decades, and includes brands like HUCOG, Pregnyl, and Novarel. It is less expensive and widely available globally.
• Recombinant HCG (rHCG): manufactured using recombinant DNA technology in Chinese Hamster Ovary (CHO) cells. The brand name is Ovidrel (choriogonadotropin alfa). It offers higher batch-to-batch consistency and slightly lower immunogenicity, but at a significantly higher cost.

Both forms are administered by injection — either intramuscularly (IM) into the thigh, deltoid, or gluteal muscle, or subcutaneously (SC) into the abdominal fat. The choice between IM and SC depends on the specific product, the dose, and the prescriber’s preference. Subcutaneous injection has become increasingly popular for lower doses because it is easier to self-administer and less painful.

How HCG differs from LH

While HCG and LH bind to the same receptor, HCG has a significantly longer half-life — approximately 24 to 36 hours, compared to just 20 minutes for LH. This means a single HCG injection provides sustained receptor stimulation for over a day, which is why it is preferred clinically over exogenous LH for most therapeutic applications.

HCG Injection Uses

HCG injections are prescribed for a surprisingly wide range of indications. Below is a detailed breakdown of every major use, from the most evidence-based to the most controversial.

Female fertility: ovulation trigger and IVF support

The most established use of HCG in reproductive medicine is as an ovulation trigger shot. During controlled ovarian stimulation — whether for timed intercourse, intrauterine insemination (IUI), or in vitro fertilization (IVF) — the woman takes gonadotropins (FSH and/or hMG) to stimulate multiple follicles to grow. When monitoring via ultrasound shows that the lead follicle has reached 18–22 mm, a single injection of 5,000 to 10,000 IU of HCG is given to trigger the final maturation and release of the egg(s).

The trigger shot mimics the natural LH surge that causes ovulation. Ovulation typically occurs 36 to 40 hours after the HCG injection, which is why egg retrieval in IVF cycles is precisely timed for 34 to 36 hours post-trigger.

HCG is also used for luteal phase support — the period after ovulation when the corpus luteum must produce enough progesterone to support a potential pregnancy. Some IVF protocols include repeated low-dose HCG injections (1,500 IU every 3 days) during the luteal phase as an alternative or supplement to progesterone supplementation.

Male hypogonadism: stimulating natural testosterone

In men, HCG stimulates the Leydig cells in the testes to produce testosterone. This makes it a valuable treatment for certain forms of male hypogonadism — particularly secondary hypogonadism, where the problem is insufficient LH signaling from the pituitary rather than primary testicular failure.

HCG monotherapy (typically 1,000 to 2,000 IU given 2 to 3 times per week) can raise testosterone levels in hypogonadal men while preserving fertility — a critical advantage over exogenous testosterone, which suppresses the HPT axis and can cause azoospermia (zero sperm count). For younger men with hypogonadism who plan to have children, HCG is often the first-line treatment.

HCG as a TRT adjunct: preventing testicular atrophy and maintaining fertility

One of the most common modern uses of HCG is alongside Testosterone Replacement Therapy (TRT). Exogenous testosterone suppresses the hypothalamic-pituitary-testicular (HPT) axis: the brain senses high testosterone levels and stops sending LH to the testes. Without LH stimulation, the Leydig cells atrophy, the testes shrink (often noticeably), intratesticular testosterone plummets, and sperm production ceases.

Adding low-dose HCG (typically 250 to 500 IU two to three times per week) to a TRT protocol keeps the Leydig cells active, maintains testicular size, preserves some degree of spermatogenesis, and supports intratesticular testosterone — which is important for libido, mood, and overall wellbeing beyond what serum testosterone alone provides.

For a deeper dive into this topic, see our dedicated guide: The Benefits of Using HCG with TRT.

Cryptorchidism (undescended testes)

HCG has been used since the 1930s to treat cryptorchidism — the condition where one or both testes fail to descend into the scrotum. The hormone stimulates testosterone production, which can promote testicular descent. Typical protocols involve 500 to 1,000 IU given 2 to 3 times per week for 4 to 6 weeks.

However, the evidence for HCG’s effectiveness in cryptorchidism is mixed. Meta-analyses report success rates of only 10 to 25%, and surgical orchidopexy remains the gold-standard treatment. HCG is now primarily used as a diagnostic tool (to confirm the testes can produce testosterone) or as a pre-surgical adjunct.

Weight loss: the HCG diet (controversial)

The “HCG diet” combines very low-dose HCG injections (125 to 200 IU daily) with a severely calorie-restricted diet of approximately 500 calories per day. The protocol was popularized by Dr. A.T.W. Simeons in his 1954 manuscript Pounds and Inches, which claimed that HCG mobilized “abnormal” fat stores and prevented the hunger and muscle loss normally associated with extreme caloric restriction.

The scientific consensus is clear: the FDA has not approved HCG for weight loss. Multiple double-blind, placebo-controlled trials have found no statistically significant difference in weight loss, hunger, or body composition between HCG and placebo when both groups followed the same 500-calorie diet. The weight loss observed on the HCG diet is attributable to the severe caloric restriction alone.

The FDA and FTC have issued warnings against over-the-counter HCG products marketed for weight loss, and the FDA requires the following statement on all HCG products: “HCG has not been demonstrated to be effective adjunctive therapy in the treatment of obesity. There is no substantial evidence that it increases weight loss beyond that resulting from caloric restriction.”

Despite these warnings, the HCG diet retains a following. If you are considering it, discuss the risks and alternatives with your doctor.

Post-cycle therapy (PCT) in bodybuilding

Anabolic-androgenic steroid (AAS) use suppresses the HPT axis, often leaving users with severely low natural testosterone production after a steroid cycle ends. Post-cycle therapy (PCT) aims to restart the HPT axis as quickly as possible to restore natural testosterone and prevent the catabolic crash that follows steroid cessation.

HCG is commonly used in PCT at doses of 1,000 to 2,000 IU every other day for 2 to 3 weeks, typically before starting a selective estrogen receptor modulator (SERM) like clomiphene or tamoxifen. The HCG stimulates the Leydig cells directly while the SERMs work at the pituitary level to restore LH and FSH. Some protocols use HCG during the last weeks of a steroid cycle (“blast and cruise” transitions) rather than after cessation.

It is important to note that HCG should not be used for extended periods during PCT, as prolonged high-dose HCG can actually desensitize the Leydig cells and suppress the HPT axis recovery it is meant to promote.

HCG Dosage Guide

HCG dosing varies enormously depending on the clinical indication. The table below summarizes the typical dosage ranges used in practice. These are general guidelines — your prescribing physician will determine the appropriate dose based on your specific situation, lab results, and response to treatment.

Dose-response considerations

Higher doses of HCG produce higher testosterone and estradiol levels, but the relationship is not linear. At doses above approximately 2,500 IU, the aromatase enzyme in adipose tissue converts a meaningful proportion of the extra testosterone into estradiol, which can cause water retention, mood changes, and gynecomastia. This is why TRT adjunct protocols use relatively low doses (250–500 IU) — enough to maintain testicular function without excessive estrogen spikes.

For the ovulation trigger, the difference between 5,000 IU and 10,000 IU appears clinically insignificant in most studies, and many fertility clinics are moving toward the lower 5,000 IU dose to reduce the risk of OHSS.

How to Administer HCG Injections

HCG is supplied as a sterile lyophilized (freeze-dried) powder in a vial, accompanied by a separate ampoule or vial of solvent for reconstitution. Proper preparation, injection technique, and storage are all critical.

For a complete visual walkthrough, see our step-by-step guide: How to Mix HCG (Human Gonadotropin).

Step 1: Reconstitution (mixing)

1. Wash your hands thoroughly and clean your workspace.
2. Remove the flip-off caps from both the HCG powder vial and the bacteriostatic water (BAC water) vial. Swab the rubber stoppers with alcohol pads.
3. Using a sterile syringe with an 18–21 gauge needle (drawing needle), withdraw the recommended amount of BAC water. For a 5,000 IU vial, 1 mL of BAC water is standard — this gives a concentration of 5,000 IU per mL (or 500 IU per 0.1 mL), making it easy to measure precise doses.
4. Inject the BAC water slowly into the HCG powder vial, aiming the stream at the glass wall rather than directly at the powder to avoid excessive foaming.
5. Gently swirl the vial until the powder is fully dissolved. Do not shake — HCG is a protein that can denature if agitated vigorously.

Step 2: Drawing and injecting the dose

1. Replace the drawing needle with a fresh injection needle. For subcutaneous injection, use a 27–31 gauge, 1/2-inch (12.7 mm) insulin syringe. For intramuscular injection, use a 22–25 gauge, 1-inch (25.4 mm) needle.
2. Draw the prescribed dose from the reconstituted vial.
3. Subcutaneous injection sites: the lower abdomen (2 inches from the navel on either side) or the front of the thigh. Pinch a fold of skin, insert the needle at a 45-degree angle, inject slowly, and release.
4. Intramuscular injection sites: the outer upper quadrant of the gluteus, the vastus lateralis (outer thigh), or the deltoid. Clean the site with alcohol, insert the needle at a 90-degree angle in a smooth motion, aspirate briefly (pull back on the plunger to check for blood), and inject slowly.
5. Dispose of all needles in a sharps container immediately after use.

Step 3: Storage

• Before reconstitution: HCG powder can be stored at room temperature (up to 25 degrees C / 77 degrees F) away from light. Check the expiry date on the vial.
• After reconstitution: refrigerate at 2–8 degrees C (36–46 degrees F). Use within 30 days of mixing. Do not freeze reconstituted HCG.
• If using bacteriostatic water (which contains benzyl alcohol as a preservative), the reconstituted solution is stable for approximately 30 days when refrigerated. If reconstituted with sterile water for injection (SWFI) instead, use within 24 hours.
• Discard any solution that appears cloudy, discolored, or contains visible particles.

Injection frequency tips

For protocols requiring multiple weekly injections (e.g., TRT adjunct at 250 IU three times per week), many patients find it helpful to inject on a fixed schedule — for example, Monday/Wednesday/Friday or every other day. Consistency helps maintain stable hormone levels and makes it easier to remember doses.

HCG Injection Side Effects

Like all hormonal medications, HCG injections carry a spectrum of potential side effects. Most are mild and related to the hormonal changes HCG induces; serious adverse events are uncommon but important to recognize.

Managing side effects

• Injection site discomfort: rotate injection sites, allow the alcohol to fully dry before injecting, and inject slowly.
• Water retention and bloating: reducing sodium intake, staying well-hydrated, and dose reduction can help.
• Estrogen-related effects (gynecomastia, mood): your physician may add a low-dose aromatase inhibitor (e.g., anastrozole 0.25–0.5 mg twice weekly) or reduce the HCG dose.
• OHSS symptoms (women): contact your fertility clinic immediately if you experience severe bloating, rapid weight gain (more than 1 kg/day), reduced urination, nausea/vomiting, or difficulty breathing after an HCG trigger shot.

HCG Products Available at MedsBase

MedsBase stocks several HCG products from leading Indian pharmaceutical manufacturers, all of which contain pharmaceutical-grade urinary-derived HCG. Below is a comparison to help you choose the right product for your needs.

How to choose

• For ovulation trigger (single high dose): HUCOG 10000IU or ZyHCG HP 10000IU provide the standard trigger dose in a single vial. The HP (Highly Purified) versions may produce fewer injection-site reactions.
• For TRT adjunct or PCT (multiple lower doses): A 5,000 IU vial (HUCOG 5000IU, Puretrig 5000IU, or Eutrig HP 5000IU) reconstituted with 1 mL BAC water provides 10 doses of 500 IU or 20 doses of 250 IU — enough for 3 to 10 weeks depending on your protocol.
• For cost efficiency on higher-dose protocols: HUCOG 10000IU at $32 is the lowest per-IU cost, while ZyHCG HP 10000IU at $29 is even more economical with the added benefit of high-purity processing.

All products ship internationally with cold-chain packaging to maintain potency during transit.

Frequently Asked Questions About HCG Injections

What is HCG used for?

HCG (Human Chorionic Gonadotropin) is used for several medical purposes: triggering ovulation in women undergoing fertility treatment, treating male hypogonadism (low testosterone), preventing testicular atrophy during testosterone replacement therapy (TRT), treating cryptorchidism (undescended testes) in boys, and in post-cycle therapy after anabolic steroid use. It is also used — controversially and without FDA approval — in some weight loss protocols.

How quickly does HCG work?

The timeline depends on the use. As an ovulation trigger shot, HCG causes ovulation within 36 to 40 hours. For testosterone stimulation in men, measurable increases in testosterone levels can be detected within 24 to 72 hours of the first injection, though clinical improvements in symptoms like energy, mood, and libido typically take 2 to 4 weeks to become noticeable. For testicular size maintenance during TRT, the effects are ongoing and become apparent within weeks of starting.

Does HCG need to be refrigerated?

Before reconstitution (mixing), HCG powder can be stored at room temperature (below 25 degrees C / 77 degrees F) away from direct light. Once mixed with bacteriostatic water, HCG must be refrigerated at 2–8 degrees C (36–46 degrees F) and used within 30 days. If mixed with sterile water for injection instead of bacteriostatic water, use within 24 hours. Never freeze reconstituted HCG.

Can men use HCG?

Yes. While HCG is most commonly associated with pregnancy, it is widely used in men’s health. HCG mimics Luteinizing Hormone (LH), which stimulates the Leydig cells in the testes to produce testosterone. It is prescribed for male hypogonadism, as a TRT adjunct to prevent testicular atrophy and maintain fertility, and in post-cycle therapy after steroid use. For a detailed breakdown, see Benefits of HCG for Men.

How long does HCG stay in your system?

HCG has a half-life of approximately 24 to 36 hours, meaning that after a single injection, blood levels drop by half every 1 to 1.5 days. It takes approximately 5 to 6 half-lives for a substance to be essentially eliminated, so HCG clears the body within approximately 5 to 9 days after the last injection. However, pregnancy tests may remain positive for up to 10 to 14 days after a high-dose trigger shot (5,000–10,000 IU), which is important to know when timing a pregnancy test after fertility treatment.

Is HCG safe?

When used at appropriate doses under medical supervision, HCG has a well-established safety profile spanning over 60 years of clinical use. Common side effects are mild (injection site discomfort, headache, bloating). Serious risks like OHSS (in women) and thromboembolism are rare and associated primarily with high-dose fertility protocols. The main concern in men is excessive estradiol elevation at higher doses, which is manageable with dose adjustment or aromatase inhibitor co-therapy. HCG should always be used under the guidance of a healthcare provider.

Do I need a prescription for HCG?

In most countries, HCG is a prescription medication. In the United States, it requires a prescription and is classified as a biologic. In the United Kingdom, EU, Australia, and Canada, it is similarly prescription-only. Some countries with less restrictive pharmaceutical regulations allow purchase without a prescription. Regardless of local regulations, you should always consult a healthcare provider before starting HCG to ensure it is appropriate for your situation, determine the correct dose, and arrange for appropriate monitoring.

What is the difference between HCG 5000 IU and 10000 IU?

The number refers to the total amount of HCG in the vial, measured in International Units (IU). A 5,000 IU vial contains half the amount of a 10,000 IU vial. The appropriate strength depends on your prescribed dose and how many doses you need per vial. For a single ovulation trigger shot, a 10,000 IU vial may be used in full. For a TRT adjunct protocol at 500 IU three times per week, a 5,000 IU vial reconstituted with 1 mL of BAC water would provide approximately 3.3 weeks of doses — while a 10,000 IU vial would last over 6 weeks.

Can HCG help with weight loss?

The HCG diet — which combines low-dose HCG injections (125–200 IU daily) with an extremely low-calorie diet (500 kcal/day) — was popularized in the 1950s. However, multiple controlled clinical trials have found no evidence that HCG itself contributes to weight loss beyond what the caloric restriction produces. The FDA has not approved HCG for weight loss, and has issued warnings against HCG products marketed for this purpose. Any weight lost on the HCG diet is attributable to the 500-calorie diet, which carries its own nutritional risks.

Can I self-inject HCG at home?

Yes, most patients who use HCG regularly (for TRT, hypogonadism, or weight loss protocols) self-inject at home after being shown the proper technique by their healthcare provider. Subcutaneous injection into the abdomen is the most common self-injection method because it is straightforward, relatively painless, and does not require anyone’s assistance. You will need proper supplies: insulin syringes (for SC) or appropriate IM needles, alcohol swabs, a sharps container, and a clean workspace. See our guide to mixing and injecting HCG for detailed instructions.

Related Guides

This is the main HCG hub article. Explore our in-depth guides on specific HCG topics:

• HCG Benefits for Men — a complete guide to using HCG for male hypogonadism, TRT support, and testosterone optimization
• Where to Buy HCG in the UK — sourcing options, legality, and what to look for when purchasing HCG
• The Benefits of Using HCG with TRT — why adding HCG to testosterone replacement therapy preserves testicular function and fertility
• Early Signs of Pregnancy After HCG Injection — how to distinguish real pregnancy symptoms from HCG trigger shot side effects
• How to Mix HCG (Human Gonadotropin) — step-by-step reconstitution and injection guide
• HCG Injection After Clomiphene Citrate Ovulation Induction — combining clomiphene and HCG for optimized ovulation timing

Written by

Sophie Chen

Pharmaceutical Content Researcher · 8 years experience

Sophie Chen is a pharmaceutical content researcher with 8 years covering generic medication access and clinical pharmacology. She specialises in international regulatory frameworks, bioequivalence standards, and patient-facing education on therapeutic drug classes. She is not a clinician.