Testosterone Supplements and Sperm Count
Yes, testosterone supplements definitively decrease sperm count and can cause complete azoospermia (zero sperm count) in men, making this a critical contraindication for any male interested in current or future fertility. 1
Mechanism of Suppression
Exogenous testosterone administration provides negative feedback to the hypothalamus and pituitary gland, resulting in inhibition of gonadotropin (LH and FSH) secretion. 1 Depending on the degree of testosterone-induced suppression, spermatogenesis may decrease or cease altogether, resulting in oligospermia or azoospermia. 1
The FDA drug label explicitly warns that large doses of exogenous androgens, including testosterone, suppress spermatogenesis through feedback inhibition of pituitary FSH, which could possibly lead to adverse effects on semen parameters including sperm count. 2
Key Physiological Points:
- Testosterone suppresses intratesticular testosterone production, which is an absolute prerequisite for normal spermatogenesis 3
- Both LH and FSH secretion are equally sensitive to the long-term negative feedback effects of testosterone administration 4
- Sperm production is suppressed in parallel with LH and FSH reductions induced by chronic testosterone administration 4
- Even at supraphysiological dosages (300 mg/week testosterone enanthate), complete azoospermia occurs in only 50-70% of men, though sperm counts are markedly reduced in all 4
Clinical Guideline Recommendations
The 2024 AUA/ASRM Guideline states unequivocally: "For the male interested in current or future fertility, clinicians should not prescribe exogenous testosterone therapy." 1 This is classified as a Clinical Principle, representing the highest level of directive guidance. 1
When Testosterone Might Be Considered:
For men who may want to pursue paternity in the more distant future, testosterone therapy may be offered, but the patient must be counseled about:
- Testosterone's inhibitory effects on spermatogenesis 1
- The time course required for resumption of spermatogenesis after cessation 1
- Recovery can take months or rarely years 1
Recovery After Discontinuation
Although recovery of sperm to the ejaculate occurs in most azoospermic males after cessation of testosterone therapy, the time course of recovery may be prolonged. 1
- Studies of hormonal contraception indicate that most men have a return of normal sperm production within 1 year after discontinuation 3
- However, recovery can be months or rarely years in some cases 1
- Therefore, exogenous testosterone therapy should be avoided in males pursuing or planning to pursue family building in the near future 1
Alternative Approaches for Men Desiring Fertility
For patients with functioning pituitary glands but low testosterone who desire fertility, the following alternatives increase endogenous testosterone production without suppressing spermatogenesis:
Preferred Options:
- Aromatase inhibitors (AIs) 1
- Human chorionic gonadotropin (hCG) 1
- Selective estrogen receptor modulators (SERMs) such as clomiphene citrate 1, 3
- These agents may be used separately or in combination to increase serum testosterone concentrations and improve spermatogenesis 1
Clomiphene citrate is a safe and effective oral therapy for men who desire to maintain future potential fertility. 3
Common Pitfalls to Avoid
Never prescribe testosterone monotherapy to men interested in fertility - this is the single most important clinical principle 1
Don't assume rapid recovery - counsel patients that fertility may not return for many months after stopping testosterone 1
Consider sperm banking - if a patient on testosterone may want future fertility, encourage sperm banking before continuing therapy 1
Recognize the severity - testosterone can cause complete azoospermia, not just reduced counts 1
Testicular Changes
Research demonstrates that testosterone causes: