Can taking testosterone affect fertility and is it permanent?

Impact of Testosterone on Fertility

Testosterone therapy significantly impairs fertility in men and should not be prescribed to males interested in current or future fertility, as it suppresses spermatogenesis and can lead to oligospermia or azoospermia that may take months or even years to recover after cessation. 1

Mechanism of Fertility Impairment

Exogenous testosterone affects fertility through several mechanisms:

• Hypothalamic-Pituitary-Gonadal (HPG) Axis Suppression: Testosterone provides negative feedback to the hypothalamus and pituitary gland, inhibiting gonadotropin secretion 1, 2
• Decreased Spermatogenesis: This hormonal suppression reduces or halts sperm production 1
• Testicular Changes: Testicular size and consistency often diminish during testosterone therapy 1

Duration and Reversibility of Effects

The impact on fertility is typically not permanent but can be prolonged:

• Recovery Timeline: After stopping testosterone therapy, recovery of sperm to the ejaculate occurs in most men, but the time course may be prolonged 1
• Recovery Period: Return to normal spermatogenesis can take months or, rarely, years 1
• Long-term Impact: In some cases (3 out of 7 subjects in one study), sperm counts remained below pre-treatment levels even 25-28 weeks after discontinuation 3
• Potential Irreversibility: The FDA label warns that "with either type of use [therapeutic or abuse], the impact on fertility may be irreversible" 2

Clinical Recommendations

For men concerned about fertility:

1. Avoid Testosterone Therapy:

   • Men planning to pursue family building in the near future should completely avoid exogenous testosterone 1
   • For those considering paternity in the more distant future, testosterone therapy may be offered only with thorough counseling about its effects 1

2. Alternative Treatments for Hypogonadism:

   • First-line therapy: Human Chorionic Gonadotropin (hCG) injections (500-2500 IU, 2-3 times weekly) 1
   • Additional options: Selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs) 1, 4
   • Novel therapy: Natesto intranasal testosterone gel may increase serum testosterone while maintaining semen parameters due to its short-acting properties 4

3. Fertility Preservation:

   • Men should be encouraged to bank sperm before starting testosterone therapy 1
   • Multiple specimens should be preserved when possible 1

Special Considerations

• Transgender and Nonbinary Individuals: Those with female birth sex using testosterone for gender-affirming care should be offered fertility preservation prior to starting therapy 5

• Monitoring: For men on testosterone therapy who later wish to conceive, semen analysis should be performed to assess recovery of spermatogenesis

• Counseling Points: Men should understand that:

  • Testosterone is not a contraceptive method (though it reduces fertility)
  • Recovery of fertility is not guaranteed
  • The longer the duration of therapy, the longer recovery may take

Warning Signs

If a man on testosterone therapy wishes to conceive, immediate cessation of testosterone is recommended, with consideration of transitioning to fertility-preserving alternatives like hCG therapy to stimulate intratesticular testosterone production while maintaining spermatogenesis.