What are the expected sexual changes and timelines for a male-to-female (MTF) transition on a protocol of estrogen (estradiol) and anti-androgen (spironolactone) therapy?

Sexual Changes and Timeline for MTF Transition on Estradiol and Spironolactone

On your protocol of estradiol and spironolactone, expect decreased libido, reduced erectile function, and changes in orgasm quality beginning within 1-3 months, with progressive changes continuing throughout the first year of therapy. 1

Sexual Function Changes

Libido and Arousal

• Decreased libido is a common and expected effect of feminizing hormone therapy, typically beginning within the first few months of treatment 1
• The reduction in testosterone levels drives this change, as testosterone is the primary hormone responsible for sexual desire in all sexes 1
• Some transgender women report changes in the quality of sexual desire—shifting from a more physically-driven urge to a more emotionally-connected experience, though this varies considerably between individuals 1

Erectile Function

• Spontaneous erections will decrease significantly or cease entirely within 1-3 months of starting therapy 2
• The ability to achieve erections with stimulation typically diminishes progressively over 3-12 months 2
• This occurs due to both testosterone suppression and the direct effects of estrogen on erectile tissue 1, 2
• Important caveat: If you wish to preserve erectile function for sexual activity or future surgical options, regular erectile activity (through masturbation or use of erectile aids) may help maintain some tissue elasticity, though this should be discussed with your provider 1

Orgasm and Sexual Response

• Orgasmic capacity is typically preserved, but the quality and sensation of orgasm often changes 1
• Many transgender women report that orgasms become more full-body, less genitally-focused, and may take longer to achieve 1
• The refractory period (time needed between orgasms) often shortens, similar to cisgender female patterns 1

Genital Changes Timeline

Testicular Changes

• Testicular volume decreases significantly, typically beginning within 3-6 months and continuing throughout the first year 1
• Fertility is progressively impaired and should be considered permanently lost after several months of therapy—sperm banking should be completed before starting hormones if fertility preservation is desired 1

Penile Changes

• Penile tissue may undergo some atrophy over time, with potential decreases in length and girth, particularly if erections are infrequent 1
• Skin texture becomes softer and thinner 1

Testosterone Suppression Reality Check

Critical limitation of your protocol: Spironolactone combined with oral estradiol frequently fails to achieve adequate testosterone suppression to female range (<50 ng/dL) 3, 4

• Only 19% of transgender women achieved female-range testosterone on spironolactone plus estradiol in one controlled trial, compared to 90% on cyproterone acetate 5
• Even on 6-8 mg daily of oral estradiol with spironolactone, nearly one-third of patients do not achieve adequate testosterone suppression 3
• Spironolactone does not enhance testosterone suppression beyond what estradiol alone provides—it works primarily as an androgen receptor blocker rather than suppressing testosterone production 3
• Paradoxically, spironolactone use was associated with difficulty achieving target estradiol levels in some studies 3

What This Means for Sexual Changes

• If your testosterone remains elevated (>50 ng/dL), you may experience:
  • Less complete reduction in libido
  • Persistent ability to achieve erections
  • Slower or incomplete feminization overall 5, 3
• You should have testosterone and estradiol levels checked at 3 months to determine if your regimen is achieving target hormone levels 1

Timeline Summary

1-3 Months

• Decreased spontaneous erections 2
• Initial reduction in libido 1
• Beginning of testicular volume reduction 1

3-6 Months

• Further decline in erectile function 2
• Continued decrease in libido 1
• Noticeable testicular atrophy 1
• Changes in orgasm quality becoming apparent 1

6-12 Months

• Stabilization of sexual function changes 1, 2
• Maximum testicular atrophy typically achieved 1
• New sexual response patterns established 1

Beyond 12 Months

• Sexual function changes are generally stable, though some subtle evolution may continue 1
• If testosterone suppression is inadequate, masculinizing effects may persist 5, 3

Monitoring and Optimization

Essential monitoring at 3 months includes 1:

• Testosterone level (target: <50 ng/dL)
• Estradiol level (target: cisgender female reference range, typically 100-200 pg/mL)

If testosterone remains elevated, discuss with your provider:

• Increasing estradiol dose (many require 6-8 mg daily) 3
• Switching to injectable or transdermal estradiol 1
• Changing from spironolactone to a more effective antiandrogen like cyproterone acetate (if available in your region) or a GnRH agonist 5, 4