Peptide Guide + Calculator
HCG Reconstitution Calculator & Guide
Human Chorionic Gonadotropin / LH-Receptor Agonist
Human chorionic gonadotropin (HCG) is a glycoprotein hormone used in FDA-approved prescription products for specific fertility and hypogonadism-related indications. In males, HCG acts similarly to luteinizing hormone by stimulating testicular Leydig cells. This page explains approved medical uses, fertility and TRT-related context, safety considerations, sports status, and educational HCG reconstitution math.
Evidence Snapshot
HCG research at a glance
Standardized regulatory and evidence context so research compounds, investigational drugs, and approved medications are not treated as if they have the same level of human evidence.
Primary mechanism
Glycoprotein gonadotropin that activates the LH receptor.
WADA context
Explicitly prohibited — S2 (male athletes)Human intervention evidence
Longstanding prescription use and clinical evidence support approved fertility and selected hypogonadism-related indications.
Human biology evidence
Well-established reproductive endocrinology and gonadotropin biology in humans.
Key takeaway
HCG is a glycoprotein hormone rather than a small peptide and has legitimate FDA-approved medical uses with a much stronger evidence base than most research compounds on the site.
Evidence labels describe the research base and regulatory context; they are not treatment, dosing, or use recommendations. Review dates describe the last BACToBasics source check for this evidence summary. Anti-doping rules can change and should be verified with the applicable authority.
HCG Reconstitution Calculator
Enter the vial amount, liquid volume, and amount you want to calculate. BACToBasics will automatically calculate concentration, liquid volume, and U-100 syringe-unit equivalents.
Loading calculator...
Calculator values are educational math inputs only. They are not recommended preparation amounts, doses, or use protocols.
HCG Reconstitution Math
Reconstitution math starts with the amount contained in the vial and the liquid volume used in the calculation. Dividing the vial amount by the liquid volume gives the resulting concentration.
Example vial amount
10,000 IU
| Liquid Volume | Calculation | Concentration |
|---|---|---|
| 1 mL | 10,000 IU ÷ 1 mL | 10,000 IU/mL |
| 2 mL | 10,000 IU ÷ 2 mL | 5,000 IU/mL |
| 3 mL | 10,000 IU ÷ 3 mL | 3,333.3333 IU/mL |
This table demonstrates concentration math only. The liquid volumes shown are examples for comparison and are not preparation recommendations.
More Reconstitution Tools
Need to compare different liquid volumes or convert between mg, mcg, mL, and U-100 units? Use the dedicated BACToBasics calculator tools.
What is HCG?
HCG stands for human chorionic gonadotropin. It is a glycoprotein hormone rather than a small synthetic peptide, although it is often grouped with peptide and hormone products because it is commonly supplied as a lyophilized injectable product. FDA-licensed HCG products include prescription drugs such as Pregnyl and Novarel.
How does HCG work in males?
In males, HCG acts as an analogue of luteinizing hormone (LH). It binds to LH receptors on Leydig cells in the testes and stimulates endogenous testosterone production. Because this stimulation occurs at the testicular level, HCG is biologically different from simply administering exogenous testosterone.
What is HCG FDA-approved for?
FDA-approved HCG products have established medical indications. Depending on the product labeling, these include selected cases of hypogonadotropic hypogonadism in males, certain cases of prepubertal cryptorchidism, and induction of ovulation and pregnancy in appropriately selected women receiving fertility treatment. HCG is a prescription medication and these indications require medical supervision.
HCG and male fertility
HCG is clinically relevant to male fertility because LH-receptor stimulation can support testicular testosterone production without directly suppressing pituitary gonadotropin output in the way exogenous testosterone does. The AUA/ASRM male-infertility guideline states that clinicians may use HCG in infertile males with low serum testosterone, including certain men with hypogonadotropic hypogonadism.
HCG and TRT
HCG is frequently discussed alongside testosterone replacement therapy because exogenous testosterone suppresses LH and FSH signaling and can reduce intratesticular testosterone and sperm production. Some small studies have explored adding HCG to testosterone in an attempt to preserve spermatogenesis, but the AUA/ASRM guideline states that the evidence is too limited to recommend this as a standard fertility-preservation strategy. Men actively pursuing fertility should discuss treatment options with a reproductive urologist or other qualified clinician.
HCG and endogenous testosterone
Because HCG stimulates Leydig cells, it can increase endogenous testicular testosterone production when the testes are capable of responding. The degree of response depends on the underlying cause of low testosterone. In primary testicular failure, where LH may already be elevated, the testosterone response to HCG may be limited.
HCG and estrogen
Increasing testicular testosterone production can also increase the amount of testosterone available for conversion to estradiol through aromatase. This is one reason estrogen-related effects such as gynecomastia or fluid retention can occur in some males receiving HCG. Individual hormone responses vary and are best evaluated with clinical symptoms and laboratory testing.
HCG and testicular size
HCG is commonly discussed in TRT communities for maintaining or restoring testicular activity and size because it directly stimulates the testes. However, maintaining testicular size is not itself an FDA-approved indication, and changes in testicular volume should not be treated as a substitute for fertility testing or semen analysis.
HCG is not an obesity or weight-loss treatment
FDA labeling specifically states that HCG has not been demonstrated to be effective as an adjunctive treatment for obesity. There is no substantial evidence that HCG increases weight loss beyond calorie restriction, improves fat distribution, or meaningfully reduces the hunger and discomfort associated with calorie-restricted diets.
Common HCG adverse effects
Reported adverse effects in HCG labeling include headache, irritability, restlessness, fatigue, edema, injection-site pain, and hypersensitivity reactions. In males, water and sodium retention and gynecomastia can occur. The adverse-effect profile differs in fertility treatment for women, where ovarian hyperstimulation syndrome and thromboembolic complications are important risks.
Important HCG safety considerations
HCG is contraindicated or requires special caution in several situations depending on the product and patient population. Product labeling includes concerns involving certain hormone-sensitive cancers, precocious puberty, allergic reactions, fluid retention, and serious complications during ovarian-stimulation treatment. Prescription HCG should be used under clinician supervision rather than treated as a general-purpose wellness hormone.
HCG and competitive sports
Under the 2026 World Anti-Doping Agency Prohibited List, chorionic gonadotrophin is included among testosterone-stimulating peptides prohibited in male athletes. It is listed in the S2 peptide-hormone category, which is prohibited at all times in and out of competition.
Prescription HCG vs research or compounded HCG
FDA-licensed products such as Pregnyl and Novarel are manufactured under regulated pharmaceutical standards. Products advertised online as research or compounded HCG should not automatically be assumed to have the same identity, biological activity, concentration, purity, sterility, storage stability, or manufacturing controls as an FDA-approved prescription product.
Why is HCG measured in IU?
HCG is commonly labeled in International Units (IU) because its potency is based on biological activity rather than simply the mass of the hormone. IU cannot be converted to milligrams or micrograms using a universal mass conversion, so BACToBasics keeps HCG calculations in IU.
HCG reconstitution math
Reconstitution calculations depend on the labeled IU in a vial and the liquid volume used. As a mathematical example, a 6,000 IU vial combined with 6mL of liquid produces a concentration of 1,000 IU per mL. BACToBasics uses examples like this only to demonstrate concentration, volume, and U-100 syringe-unit math rather than to provide an HCG dosing or treatment protocol.
Explore more about HCG
10 linksComparisons, research records, development tracking, blends, and related guides are available here when you want to go deeper.
Explore more about HCG
10 linksComparisons, research records, development tracking, blends, and related guides are available here when you want to go deeper.
Research, updates & development
Jump from the guide into the public update timeline, compound-specific research records, and clinical-development tracker without searching again.
HCG research & development updates
Open the public timeline of sourced research records and material development changes tracked by BACToBasics.
Open →
ResearchHCG research sources
Open 1 curated research record for HCG.
Open →
DevelopmentHCG clinical development
Approved · Approved. Longstanding FDA-licensed prescription products including Pregnyl.
Open →
Related peptide guides
Related guides are ranked from shared comparison pages, shared blend pages, and peptide category rather than a hand-maintained link list.
CJC-1295 guide & calculator
Growth Hormone & Performance · Long-Acting Growth Hormone-Releasing Hormone Analog
Open →
Peptide guideGHRP-2 guide & calculator
Growth Hormone & Performance · Pralmorelin / GH-Releasing Peptide-2
Open →
Peptide guideGHRP-6 guide & calculator
Growth Hormone & Performance · Growth Hormone-Releasing Peptide-6
Open →
Peptide guideGonadorelin guide & calculator
Growth Hormone & Performance · Gonadotropin-Releasing Hormone / GnRH
Open →
Relevant glossary concepts
Definitions are matched against the guide's structured title, subtitle, description, and educational sections.
FDA-Approved
A status indicating that the FDA has approved a specific drug product for one or more labeled uses after reviewing the required evidence and manufacturing information.
Open →
GlossaryInternational Unit (IU)
A substance-specific unit of biological activity that cannot be converted generically to mg or mcg.
Open →
GlossaryMilliliter (mL)
A metric unit of liquid volume equal to one-thousandth of a liter.
Open →
HCG FAQ
Tap a question to expand only the answer you want to read.
Is HCG FDA-approved?
Yes. HCG is the active hormone in FDA-approved prescription products such as Pregnyl and Novarel. Approved uses depend on the product and include specific fertility and hypogonadism-related indications.
Is HCG the same as LH?
No. HCG and luteinizing hormone are different hormones, but HCG activates the same LH receptor and can mimic many of LH's effects on Leydig cells in the testes.
Can HCG increase testosterone?
Yes. In males with responsive testicular tissue, HCG can stimulate Leydig cells and increase endogenous testosterone production. The response depends on the cause of the underlying hormone deficiency.
Can HCG help male fertility?
HCG has established medical use in selected males with hypogonadotropic hypogonadism and is also used in male-infertility care. Whether it is appropriate depends on hormone testing, semen analysis, fertility goals, and the underlying diagnosis.
Does HCG preserve fertility while on TRT?
Small studies have explored adding HCG to exogenous testosterone to help preserve spermatogenesis, but the AUA/ASRM guideline states that the evidence is too limited to recommend this approach as a standard fertility-preservation strategy. Exogenous testosterone itself can substantially suppress sperm production.
Can HCG increase estradiol?
It can. By increasing testicular testosterone production, HCG can also increase substrate available for conversion to estradiol. The magnitude of the effect varies between individuals.
Can HCG cause gynecomastia?
Yes. Gynecomastia is listed among reported adverse reactions in males receiving HCG and may be related to changes in androgen and estrogen signaling.
Does HCG help with weight loss?
No proven weight-loss benefit has been established. FDA labeling specifically states that HCG has not been demonstrated to increase weight loss beyond calorie restriction or improve fat distribution in obesity treatment.
Is HCG a peptide?
HCG is more accurately described as a glycoprotein hormone composed of protein subunits with attached carbohydrate groups. It is often grouped with peptide hormones in general discussions, but it is structurally more complex than the small synthetic peptides commonly sold for research use.
Why is HCG measured in IU instead of mg?
HCG potency is expressed in International Units because IU represent standardized biological activity. There is no general IU-to-mg conversion that should be applied to HCG.
Is HCG banned in sports?
For male athletes subject to WADA rules, chorionic gonadotrophin is prohibited under the S2 peptide-hormone category at all times, both in and out of competition.
How do you calculate HCG reconstitution concentration?
Divide the labeled IU in the vial by the liquid volume. For example, 6,000 IU divided by 6mL equals 1,000 IU per mL. This is concentration math rather than a recommendation for how HCG should be prepared or used.
Can the BACToBasics calculator handle HCG math?
Yes. The HCG calculator keeps calculations in IU and can calculate concentration, equivalent liquid volume, U-100 syringe units, and approximate amounts per vial. BACToBasics provides educational math rather than medical or dosing advice.
Sources & References
5 sourcesOpen the references when you want to inspect the research and regulatory sources behind this guide.
Sources & References
5 sourcesOpen the references when you want to inspect the research and regulatory sources behind this guide.
Current U.S. prescribing information covering approved indications, contraindications, adverse reactions, male effects, and the statement that HCG has not been shown to improve weight loss in obesity.
U.S. prescribing information covering clinical use, safety warnings, adverse reactions, and reconstitution-related product information.
FDA biologic product record listing Pregnyl as a licensed prescription chorionic gonadotropin product and documenting its U.S. approval history.
Clinical guideline discussing HCG as an LH analogue, its role in selected infertile males with low testosterone, and the limited evidence for preserving spermatogenesis when HCG is added to exogenous testosterone.
Lists chorionic gonadotrophin among testosterone-stimulating peptides prohibited in male athletes under S2 at all times.
BACToBasics provides educational information and math tools only. This content is not medical advice, dosing advice, injection instruction, or a recommendation to use any peptide or medication.