When someone stops using Gonadotropin-releasing hormone agonists (GnRHa), their testosterone levels may remain low or even decrease further. GnRHa are medications used to suppress the production of testosterone in individuals assigned male at birth (AMAB) who are undergoing feminizing hormone therapy or gender-affirming care.
Here’s why:
- Suppression by estrogen therapy: If you are taking estrogen as hormone replacement therapy, your body will consider that it has enough hormones and that can lead to continued testosterone suppression.
- Rebound Effect: GnRHa work by initially causing an increase in testosterone levels (a flare-up) followed by a sustained suppression. When someone stops using GnRHa, there can be a rebound effect, where the body begins to produce more testosterone than usual before eventually returning to baseline levels. This temporary increase in testosterone levels can be followed by a period of lower-than-normal testosterone levels.
- Hypogonadism: Prolonged use of GnRHa can lead to suppression of the pituitary gland’s ability to produce luteinising hormone (LH) and follicle-stimulating hormone (FSH), which are needed for testosterone production. After stopping GnRHa, it may take some time for the pituitary gland to recover and resume normal hormone production, resulting in persistently low testosterone levels.
- Testicular Function: GnRHa can also directly suppress testicular function, leading to decreased testosterone production by the testes. Even after discontinuing GnRHa, it may take time for the testes to regain full function and resume normal testosterone production.
- Individual Variability: Some individuals may have different responses to stopping GnRHa based on factors such as age, overall health, duration of GnRHa use, and underlying medical conditions.