Purpose of HCG Administration in Men
Human Chorionic Gonadotropin (HCG) is primarily administered to men to treat secondary hypogonadism and preserve or restore fertility, as it stimulates the testes to produce testosterone while maintaining spermatogenesis, unlike exogenous testosterone therapy which can suppress sperm production. 1, 2
Mechanism of Action
HCG functions similarly to luteinizing hormone (LH) in men, with these key effects:
- Stimulates Leydig cells in the testes to produce testosterone 1
- Maintains or initiates spermatogenesis 2
- Helps with testicular descent in cases where no anatomical impediment exists 1
- Has a small degree of FSH activity in addition to its primary LH-like action 1
Clinical Indications for HCG in Men
1. Secondary Hypogonadism with Fertility Concerns
- First-line treatment for men with secondary hypogonadism who wish to preserve fertility 2
- Approximately 75% of patients achieve sperm production when HCG is combined with FSH 2
- Unlike testosterone replacement therapy, HCG does not suppress spermatogenesis 3
2. Hypogonadal Symptoms with Normal Testosterone
- Can improve symptoms in men with testosterone levels >300 ng/dL who still experience hypogonadal symptoms 4
- Studies show improvement in erectile dysfunction (86%) and libido (80%) in symptomatic men with normal testosterone levels 5
- Mean testosterone improvements of approximately 50% have been reported 4
3. Reversing Effects of Exogenous Testosterone
- Used to restore testicular function and spermatogenesis in men who have been on testosterone replacement therapy 2
- Particularly important for men on exogenous testosterone who are planning future reproduction 2
Treatment Protocols and Efficacy
- Often combined with FSH for optimal outcomes, especially in cases of complete hypogonadotropic hypogonadism 2
- Treatment duration typically ranges from 8-24 months 4, 6
- Success rates for inducing spermatogenesis approach 80% in hypogonadotropic hypogonadism 6
- Pregnancy rates of approximately 50% have been reported when used for fertility treatment 6
Monitoring and Side Effects
Monitoring Parameters
- Regular assessment of testosterone levels every 3-6 months 2
- Semen analyses to evaluate spermatogenesis 2
- Monitoring for side effects
Common Side Effects
- Gynecomastia (most common) due to increased estradiol from aromatase stimulation 6
- No significant adverse effects on hematocrit, PSA, or hemoglobin A1c have been reported 5
- No increased risk of thromboembolic events has been observed in studies 5
Factors Affecting Treatment Response
- Post-pubertal onset of hypogonadism responds better than congenital forms 6
- Larger baseline testicular volume predicts better outcomes 6
- History of cryptorchidism may negatively impact response 7
- Multiple pituitary hormone deficiencies may reduce efficacy 7
Clinical Considerations
- HCG has no known effect on fat mobilization, appetite, hunger, or body fat distribution 1
- Prior androgen therapy does not appear to adversely affect response to HCG treatment 7
- Combined therapy with HCG and FSH shows better outcomes than monotherapy for fertility 6
HCG represents an important therapeutic option for men with hypogonadism, particularly when fertility preservation is desired or when symptomatic improvement is needed despite normal testosterone levels.