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Home » Prescriptions and Pharmacies » Effects of Feminising Hormone Treatment on Penile Anatomy and Physiology

Effects of Feminising Hormone Treatment on Penile Anatomy and Physiology

Choosing Medication, Feminisation Therapy, Prescriptions and Pharmacies

For many trans women and transfeminine people, oestrogen is an essential part of feminising hormone treatment. However, feminising hormone treatment with oestrogen can cause changes in penile anatomy and physiology, including penile atrophy (shrinkage of erectile tissue in the penis) and erectile dysfunction (decreased capacity for penile erection). For people who engage in sexual activity involving penile stimulation, these effects can be extremely distressing.

Unfortunately, there is very little research on penile atrophy in the context of feminising hormone treatment in trans women. Most of the evidence on the effects of oestrogen on penile anatomy and physiology comes from research on cis men diagnosed with hypogonadism (Chiang et al., 2009; Srilatha and Adaikan, 2004; Zuniga et al., 2019). These studies have suggested that oestrogen and a lack of testosterone can be associated with erectile dysfunction.

Mechanisms

Feminising hormone treatment causes the changes in penile anatomy and physiology in the following ways.

Antiandrogens and oestrogen in feminising hormone treatment suppress testosterone production, which decreases the frequency of penile erections. This is known as erectile dysfunction.
Due to the widespread physiological effects of oestrogen, feminising hormone treatment can change the sensations from the penis, which can make penile stimulation uncomfortable.
Over time, the loss of erections can result in shrinkage of the erectile tissue in the penis, as the smooth muscles in the penis are no longer being stretched regularly. This is known as penile atrophy.

Treatment

Penile atrophy

Penile atrophy can be counteracted by engaging in regular sexual activity or masturbation that stimulates penile erection. Stimulating penile erection at least two to three times a week can help to keep the erectile tissue stretchy and flexible.

In order to reduce irritation, sexual activity or masturbation can be aided with the use of a lubricant.

Erectile dysfunction

While feminising hormone treatment decreases the frequency of spontaneous erections, most people maintain the capacity to achieve erections in response to sexual desire and stimulation. However, if erectile dysfunction is a problem, then there are potential ways it can be overcome.

1. Increasing testosterone

Because the loss of erectile capacity is predominantly due to the absence of testosterone, erectile capacity may return by allowing the testosterone level in the body to increase slightly. This can be achieved in two ways:

By decreasing the dose of the antiandrogen, so that testosterone production is only partially suppressed;
By using a low dose of testosterone gel.

The testosterone gel acts systemically, and so can be applied anywhere on the body. However, applying it to the genitals is not recommended, as the alcohol in the gel can cause skin irritation in sensitive areas.

This may require some fine tuning of treatment, as increasing the testosterone level too much could result in unwanted masculinising effects. Nonetheless, it is important to note that cis women also have low levels of testosterone circulating around their bodies, as testosterone is not only produced by the testes, but is also produced by the ovaries and adrenal glands.

If you choose to add testosterone to your Treatment Recommendation request, please do not add it to the main part of the form. The testosterone should be selected as an add-on for £10.

2. Phosphodiesterase-5 inhibitors

There are medications called phosphodiesterase 5 inhibitors, which increase blood flow to the penis during sexual stimulation and cause penile erection. These include sildenafil (Viagra®) and tadalafil (Cialis®), which can be taken prior to sexual activity. These are readily available in pharmacies or through healthcare providers.

If you feel like you might benefit from sildenafil for erectile dysfunction, you can purchase a recommendation for sildenafil as an add-on (for £10) when you submit your Treatment Recommendation request form.

References

Chiang, H. S., Cho, S. L., Lin, Y. C., and Hwuang, T. I. S. (2009). “Testosterone gel monotherapy improves sexual function of hypogonadal men mainly through restoring erection: evaluation by IIEF score”. Urology, 73: 762-766.
Srilatha, B., and Adaikan, P. G. (2004). “Estrogen and phytoestrogen predispose to erectile dysfunction: do ER-alpha and ER-beta in the cavernosum play a role?” Urology, 63: 382-386.
Zuniga, K. B., Margolin, E. J., De Fazio, A., Ackerman, A., and Stahl, P. J. (2019). “The association between elevated serum oestradiol levels and clinically significant erectile dysfunction in men presenting for andrological evaluation”. Andrologia, 51: e13345.