Hormone Surges with Gonadotropic Releasing Hormone Analogues (GnRHas)

Hormone Surges with Gonadotropic Releasing Hormone Analogues (GnRHas)

Gonadotropic releasing hormone analogues (GnRHas) are a class of medications used to suppress puberty. They include nafarelin (Synarel), triptorelin (Decapeptyl), and leuprorelin (Prostap).

Usually, during unopposed puberty, the hypothalamus (part of the brain) releases GnRH. This acts on the pituitary gland (a gland situated below the brain) and stimulates it to produce follicular stimulating hormone (FSH) and luteinising hormone (LH). FSH and LH act on the gonads (testes or ovaries) and stimulate them to produce sex hormones (testosterone or oestrogen). These act on the bodily tissues to produce the changes associated with puberty.

GnRHa's work by binding to the GnRH receptors on the hypothalamus. This eventually results in the pituitary gland ceasing to produce FSH and LH, which in turn results in suppression of testosterone and oestrogen production by the gonads. Due to the lack of testosterone and oestrogen, the bodily changes associated with puberty are halted.

While GnRHa's eventually suppress testosterone and oestrogen production, some people exhibit an initial temporary rise in testosterone and oestrogen when commencing GnRHa's. This occurs because the initial binding of the GnRHa's to the pituitary gland causes some stimulation of the pituitary gland, which results in an initial surge in FSH and LH secretion. However, after this initial surge, the pituitary gland is no longer stimulated and stops producing FSH and LH, which in turn results in more prolonged testosterone and oestrogen suppression.

The initial surge in hormones upon commencing GnRHa's is not usually a problem in the context of gender affirming healthcare. As noted above, the rise in testosterone and oestrogen is brief and temporary. This is usually an insufficient amount of time for the hormones to produce any significant masculinising or feminising changes.

Nonetheless, if you are already taking an antiandrogen and are switching to a GnRHa, then there is the option of overlapping your old antiandrogen with the GnRHa for a couple of weeks to mitigate any potential effects from the initial hormone surge.

References

Brik, T., Vrouenraets, L. J. J. J., de Vries, M. C., and Hannema, S. E. (2020). "Trajectories of Adolescents Treated with Gonadotropin-Releasing Hormone Analogues for Gender Dysphoria". Archives of sexual behavior, 49 (7): 2611–2618.

Kumar, P., and Sharma, A. (2014). "Gonadotropin-releasing hormone analogs: Understanding advantages and limitations". Journal of human reproductive sciences, 7(3): 170–174.

Nos, A. L., Klein, D. A., Adirim, T. A., et al. (2022). "Association of Gonadotropin-Releasing Hormone Analogue Use With Subsequent Use of Gender-Affirming Hormones Among Transgender Adolescents". JAMA Network Open, 5 (11): e2239758.


    • Related Articles

    • Starting Hormone Therapy as a Young Individual: A Comprehensive Guide

      Introduction: Embarking on hormone therapy is a significant step in the journey of gender affirmation, especially for younger people. The process varies depending on whether you are already on puberty blockers or beginning your treatment journey from ...
    • Optimising Height in Transgender Youth Having Hormone Therapy

      For transgender youth, accessing gender-affirming hormone therapy is a key step in helping align their physical characteristics with their gender identity. One aspect of this process is managing the impact of these hormones on growth and height, ...
    • Spironolactone for Transfeminine Adolescents

      Background Puberty blockade is an important part of gender affirming medical care for many trans adolescents. Usually, gonadotropin releasing hormone analogues (GnRHas) would be used to inhibit pubertal changes. However, the provision of GnRHas for ...
    • Cyproterone Acetate for Transfeminine Adolescents

      Background Puberty blockade is an important part of gender affirming medical care for many trans adolescents. Usually, gonadotropin releasing hormone analogues (GnRHas) would be used to inhibit pubertal changes. However, the provision of GnRHas for ...
    • SERMs for Transmasculine Adolescents

      Background Puberty blockade is an important part of gender affirming medical care for many trans adolescents. Usually, gonadotropin releasing hormone analogues (GnRHas) would be used to inhibit pubertal changes. However, the provision of GnRHas for ...