HCG vs Clomid: How They Differ

HCG (human chorionic gonadotropin) is a two-chain glycoprotein hormone that acts like LH directly on the ovaries and testes, while Clomid (clomiphene citrate) is an oral selective oestrogen receptor modulator that works one level higher, blocking oestrogen feedback so the pituitary releases more LH and FSH. HCG stands in for the pituitary signal; clomiphene turns the pituitary up. Both are approved medicines with fertility indications, and both have been studied in men as ways to raise testosterone without shutting down the testes. In the one randomised trial that compared them in men, testosterone rose by the same amount on each.

Findings

• In a randomised trial of 282 men with hypogonadism who wanted to preserve fertility, clomiphene, HCG and the two together all raised testosterone, with no significant difference between groups after three months (2018).
• Low-dose HCG kept intratesticular testosterone in the normal range in healthy men whose LH and FSH had been suppressed by testosterone injections, where testosterone alone cut it by 94% (2005).
• In 26 men on testosterone therapy with concurrent HCG, no man became azoospermic over a mean 6.2 months, and 9 contributed to a pregnancy (2013).
• In 46 hypogonadal men, clomiphene raised testosterone from 228 to 612 ng/dL at one year and held it near that level for three years (2012). In 626 women with PCOS, it produced a 22.5% live-birth rate against 7.2% with metformin (2007).

What is HCG?

HCG is a glycoprotein hormone made of two subunits, alpha and beta, joined non-covalently; it is similar in structure to luteinising hormone (LH), and its classic role in pregnancy is to keep the corpus luteum making progesterone (Cole, Reprod Biol Endocrinol, 2009). Because of that likeness, it acts on the same receptor as LH. In the testes, that receptor sits on the Leydig cells that make testosterone, so HCG stimulates them directly without any signal from the pituitary. It is measured in international units rather than milligrams, as explained in HCG: What It Is, Why It Is Measured in IU, and Its Clinical History.

Prescription HCG labels list prepubertal cryptorchidism not due to anatomical obstruction and hypogonadotropic hypogonadism in males, and, in women, ovulation induction in anovulatory infertility (Canadian and US chorionic gonadotropin labels).

HCG and the testes on testosterone therapy

External testosterone suppresses LH and FSH, and testosterone inside the testes falls with them. In a 2005 study, 29 healthy men received weekly testosterone injections with either placebo or one of three low HCG amounts for three weeks. On testosterone alone, LH and FSH fell to 5% and 3% of baseline and intratesticular testosterone fell by 94%. Intratesticular testosterone rose in line with the HCG amount, and relatively low HCG amounts kept it within the normal range (Coviello et al., J Clin Endocrinol Metab, 2005).

A 2013 clinic series followed 26 men, mean age 35.9, on testosterone therapy with concurrent low-dose HCG. Semen parameters did not change over more than a year of follow-up, no man became azoospermic, and 9 of the 26 contributed to a pregnancy with their partner (Hsieh et al., J Urol, 2013). The detail is in HCG with TRT: What It Does for Testosterone, the Testes and Fertility.

What is Clomid (clomiphene)?

Clomiphene citrate is a non-steroidal selective oestrogen receptor modulator approved for ovulatory dysfunction in women. It is a mixture of two isomers, zuclomiphene and enclomiphene, and the testosterone-raising effect in men is attributed mainly to enclomiphene (Earl and Kim, Expert Rev Endocrinol Metab, 2019). It blocks oestrogen’s negative feedback at the hypothalamus and pituitary, so GnRH, LH and FSH rise and the gonads respond. Unlike HCG, it needs a pituitary that can answer.

Clomiphene in women

The largest modern trial randomised 626 infertile women with polycystic ovary syndrome to clomiphene, metformin, or both for up to six months. Live-birth rates were 22.5% with clomiphene, 7.2% with metformin and 26.8% with the combination; multiple pregnancies occurred in 6.0% of clomiphene pregnancies (Legro et al., N Engl J Med, 2007).

Clomiphene in men

Use in men is outside the approved indication but well studied. In 86 hypogonadal men with a mean age of 29, most seeking fertility treatment, testosterone and gonadotropins all rose over a mean 19 months of clomiphene, symptom scores improved, and no major side effects were recorded (Katz et al., BJU Int, 2012). In 46 men treated for over a year, testosterone rose from 228 ng/dL to 612 at one year and 582 at three years, and bone density at the hip and spine improved (Moskovic et al., BJU Int, 2012). In 12 healthy men, 30 days of clomiphene raised testosterone 146%, LH 177% and FSH 170% (Miller et al., J Clin Endocrinol Metab, 2019). An age-matched comparison found clomiphene raised median testosterone from 247 to 504 ng/dL, with satisfaction similar to testosterone gels and injections (Ramasamy et al., J Urol, 2014).

What happened when they were compared directly?

A 2018 randomised study assigned 282 hypogonadal men who wished to preserve fertility to clomiphene (95), HCG injections (94) or both (94). Mean testosterone rose from 2.31 to 5.17 nmol/L, a 223% increase, with no statistically significant difference between the three arms at one or three months. Symptom scores improved in every group, most in the combined arm (Habous et al., BJU Int, 2018).

How do HCG and clomiphene compare side by side?

Question	HCG	Clomid (clomiphene)
What is it?	Glycoprotein hormone, LH-like	Selective oestrogen receptor modulator
Size	Two protein subunits (alpha and beta)	Small non-peptide molecule, two isomers
Where it acts	LH receptor in ovaries and testes	Oestrogen receptors in hypothalamus and pituitary
Needs a working pituitary?	No	Yes
Approved uses	Male hypogonadotropic hypogonadism, cryptorchidism, ovulation induction	Ovulatory dysfunction in women
Human evidence in men	Physiology studies, clinic series, one RCT vs clomiphene	Case series, cohort comparisons, one RCT vs HCG
Forms we supply	5,000 IU lyophilised vial	Not supplied

Which fits which research question?

• Leydig-cell and intratesticular testosterone research: HCG, which acts on the testes directly and works when the pituitary is suppressed, as in the testosterone-therapy studies.
• Hypothalamic and pituitary feedback: clomiphene, whose effect depends on releasing the oestrogen brake.
• Further up the axis: kisspeptin acts above both, on GnRH neurons, compared in Kisspeptin vs HCG; clomiphene’s active isomer is covered in Kisspeptin vs Enclomiphene.

How is HCG supplied?

Vistara Labs supplies HCG as a 5,000 IU lyophilised vial, reconstituted with bacteriostatic water (see the HCG reconstitution guide). Certificates of analysis are on the lab reports page, buying details are in Buy HCG in Canada, and every order ships from within Canada. Vistara Labs does not supply clomiphene.

Frequently asked questions

What is the difference between HCG and Clomid?

HCG is an LH-like glycoprotein hormone that stimulates the testes or ovaries directly. Clomid (clomiphene citrate) is an oral selective oestrogen receptor modulator that blocks oestrogen feedback in the brain, so the pituitary releases more LH and FSH.

Is HCG or Clomid better for raising testosterone?

In the one randomised trial comparing them, 282 hypogonadal men on clomiphene, HCG or both all raised testosterone, with no statistically significant difference between groups after three months.

Does HCG maintain testicular function during testosterone therapy?

In studies, yes. Low-dose HCG kept intratesticular testosterone in the normal range in men on testosterone injections, and in 26 men on testosterone therapy with HCG no one became azoospermic and 9 contributed to a pregnancy.

Have HCG and clomiphene been studied together?

Yes. A 2018 randomised trial included a combined arm alongside clomiphene alone and HCG alone. Testosterone rose to a similar level in all three, and symptom scores improved most in the combined arm.

Where can I buy HCG in Canada?

Vistara Labs supplies HCG as a 5,000 IU lyophilised vial for laboratory research, with certificates of analysis online, shipped from within Canada by Canada Post Xpresspost.

Product details from vistaralabs.ca, October 2026. Sources: Cole LA. New discoveries on the biology and detection of human chorionic gonadotropin. Reprod Biol Endocrinol. 2009. PMID 19171054. Coviello AD et al. Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression. J Clin Endocrinol Metab. 2005. PMID 15713727. Hsieh TC et al. Concomitant intramuscular human chorionic gonadotropin preserves spermatogenesis in men undergoing testosterone replacement therapy. J Urol. 2013. PMID 23260550. Earl JA, Kim ED. Enclomiphene citrate: a treatment that maintains fertility in men with secondary hypogonadism. Expert Rev Endocrinol Metab. 2019. PMID 31063005. Legro RS et al. Clomiphene, metformin, or both for infertility in the polycystic ovary syndrome. N Engl J Med. 2007. PMID 17287476. Katz DJ et al. Outcomes of clomiphene citrate treatment in young hypogonadal men. BJU Int. 2012. PMID 22044663. Moskovic DJ et al. Clomiphene citrate is safe and effective for long-term management of hypogonadism. BJU Int. 2012. PMID 22458540. Miller GD et al. Hypothalamic-pituitary-testicular axis effects and urinary detection following clomiphene administration in males. J Clin Endocrinol Metab. 2019. PMID 30295816. Ramasamy R et al. Testosterone supplementation versus clomiphene citrate for hypogonadism: an age matched comparison of satisfaction and efficacy. J Urol. 2014. PMID 24657837. Habous M et al. Clomiphene citrate and human chorionic gonadotropin are both effective in restoring testosterone in hypogonadism: a short-course randomized study. BJU Int. 2018. PMID 29772111. Canadian chorionic gonadotropin product monograph (Fresenius Kabi Canada) and US chorionic gonadotropin labelling, indications.

More on this: HCG with TRT: What It Does for Testosterone, the Testes and Fertility.