Oligospermia: do hCG, hMG or clomiphene actually work?

LH drives the Leydig cells to make the high intratesticular testosterone concentration that sperm production requires. FSH drives Sertoli cells to support the developing germ cells through spermatogenesis.

The 2024 APHRODITE criteria turn that physiology into five clinically useful groups: hypogonadotropic hypogonadism, congenital or acquired; idiopathic infertility with low semen parameters, normal FSH and normal total testosterone; low semen parameters with normal FSH but reduced total testosterone; low semen parameters with elevated FSH and reduced or normal testosterone; and unexplained male infertility within unexplained couple infertility.^[12]

Hormonal therapy has its strongest rationale in group 1, a plausible rationale in groups 2 and 3, and its weakest in group 4. A high FSH means the pituitary is already shouting and the testis cannot answer. Shouting louder rarely helps.

A 2026 systematic review pooled 50 studies and 1,583 men with hypogonadotropic hypogonadism and azoospermia. Gonadotropins induced spermatogenesis in 74% (95% CI 66–82%), with a mean 11.8 months to the first sperm. Among couples with a child wish, pregnancy reached 52% (95% CI 42–62%) after a mean 19 months from starting treatment. Mean post-treatment sperm concentration was only 9.8 million/mL (95% CI 8.6–11.0), yet spontaneous pregnancies occurred below normal semen thresholds. Dual gonadotropin therapy outperformed hCG alone. The important brake on certainty is that the authors judged most included studies methodologically poor.^[1]

An earlier meta-analysis found overall success of 75% (69–81%) with gonadotropins and 75% (60–85%) with GnRH; mean sperm concentrations were 5.92 and 4.27 million/mL. Pre-pubertal-onset disease did worse than mixed pre- and post-pubertal populations: 68% (58–77%) versus 84% (76–89%), p=0.011, and 3.37 versus 12.94 million/mL, p<0.0001. Urinary and recombinant FSH performed the same. Lower baseline gonadotropins and combined hCG plus FSH predicted greater success. Previous testosterone replacement did not compromise the outcome.^[2]

A 2025 retrospective series treated 65 men with prepubertal-onset disease using hCG three times weekly for four weeks, then hCG plus recombinant FSH. Median baseline testosterone was 0.10 ng/mL, LH 0.05 IU/L, FSH 0.50 IU/L and testicular volume 4.0 mL. After priming, testosterone reached 3.16 ng/mL. Among 50 analysed men, testicular volume rose to 9.0 mL and 41 (82%) produced sperm at a median 7.5 months, with median concentration 5.2 million/mL, motility 35% and morphology 4%. Congenital and acquired causes did equally well. Baseline testicular volume was the only predictor of success — and of speed.^[3]

Put plainly: two thirds to four fifths of these men will make sperm. Counts usually remain below the “normal” reference range, and are often still sufficient for natural conception. Baseline testicular volume is the most useful bedside predictor.

A 2025 network meta-analysis of 24 controlled studies in 1,676 men compared aromatase inhibitors, SERMs and FSH. Clomiphene citrate 25 mg every other day ranked highest for sperm concentration: +22.00 million/mL (95% CI 14.75–29.25; P-score 99%), and for total sperm number: +66.70 (95% CI 27.53–105.87). FSH 300 IU every other day improved concentration by 9.34 million/mL (95% CI 5.14–13.53). No treatment significantly improved progressive motility. Dose response ran in opposite directions: direct for FSH, inverse for SERMs — lower clomiphene doses did better.^[4]

A 2024 network meta-analysis of 14 randomised trials in 1,342 men also ranked clomiphene first (SUCRA 97.4), ahead of antioxidants, aromatase inhibitors and tamoxifen — but it did not significantly beat placebo (SMD −1.53, 95% CI −3.52 to 0.47). Trial quality was low, and the authors concluded that evidence was insufficient for routine use.^[5]

Pregnancy syntheses disagree. An 11-RCT meta-analysis of oestrogen antagonists reported OR 2.42 (95% CI 1.47–3.94, p=0.0004), with concentration up 5.24 million/mL, motility up 4.55% and no excess adverse events.^[6] A 2024 synthesis restricted to placebo comparisons found pregnancy in 10.4% on clomiphene versus 7.1% on placebo: OR 1.30 (95% CI 0.27–6.17, p=0.74).^[7] A 16-trial SERM meta-analysis found gains in total count, morphology and pregnancy, but not concentration or motility.^[8]

For FSH, 15 controlled studies — 614 treated men and 661 controls — produced a spontaneous-pregnancy OR of about 4.5 (95% CI 2.17–9.33) and post-ART pregnancy OR 1.60 (95% CI 1.08–2.37). Concentration rose 2.66 million/mL (0.47–4.84), without a significant gain in progressively motile sperm concentration (1.22, 95% CI −0.07 to 2.52). The authors warned about heterogeneity, bias and the lack of criteria for choosing recipients.^[9] The older Cochrane estimate was OR 4.17 (95% CI 1.30–7.09), based on only four RCTs and 278 participants, with no live-birth or miscarriage data and insufficient evidence overall.^[10]

A 61-study European review found improvements in semen parameters with FSH, tamoxifen, pentoxifylline, coenzyme Q10, L-carnitine and kallikrein, but rated certainty very low for every outcome and found very limited evidence of better pregnancy or live birth.^[11] The effect on the report is more reliable than the effect on a baby.

AUA/ASRM says FSH analogues may improve concentration, pregnancy and live birth in idiopathic infertility (Conditional Recommendation, Grade B). SERMs and hCG may be used in infertile men with low testosterone (Conditional, Grade C), while men should be told that SERMs offer limited benefit relative to assisted reproductive technology.^[15]

Exogenous testosterone suppresses LH and FSH. Intratesticular testosterone collapses, and sperm production falls with it — oligospermia or outright azoospermia. AUA/ASRM Statement 42 is a Clinical Principle: clinicians should not prescribe exogenous testosterone therapy to a man interested in current or future fertility.^[15]

Route does not change the mechanism. Whether testosterone is delivered by gel or injection, negative feedback suppresses the pituitary. By contrast, hCG acts as an LH analog and drives the Leydig cell directly.

Recovery is often possible. In 49 men who presented with azoospermia or severe oligospermia below 1 million/mL while on testosterone, hCG 3,000 IU subcutaneously every other day plus clomiphene, tamoxifen, anastrozole or recombinant FSH restored spermatogenesis or improved counts in 47 (95.9%). Mean time was 4.6 months and mean first sperm density was 22.6 million/mL.^[13]

Prevention is cleaner than recovery. In a phase II randomised trial, enclomiphene citrate raised morning total testosterone to levels comparable with 1% topical testosterone gel while increasing LH and FSH and conserving sperm counts. The gel did not.^[14]

Hormonal therapy for oligospermia is not one treatment question. In true hypogonadotropic hypogonadism, replacing the missing LH and FSH signals works in about three quarters of men, even when the final count remains below the reference range. In idiopathic infertility with normal gonadotropins, clomiphene and FSH can improve the report, but the evidence that they improve the chance of a baby remains inconsistent.

The safest sequence is cause first, drug second, and time third. Testosterone sits outside that sequence: it suppresses the signals sperm production needs and should not be used when fertility matters.

This article is educational and not medical advice. Fertility medicines are prescription therapies; diagnosis, dosing and monitoring belong with a reproductive urologist or other qualified physician.