Testosterone is a hormone found in both males and females, though in higher concentrations in males. It influences male secondary sexual characteristics like increased muscle mass and facial/body hair growth. It also contributes to bone density, red blood cell production, and fat distribution.
The Hormonal Mechanism of Period Cessation
The menstrual cycle is regulated by hormones from the hypothalamus, pituitary gland, and ovaries. The hypothalamus releases gonadotropin-releasing hormone (GnRH), which signals the pituitary gland to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These stimulate the ovaries to produce estrogen and progesterone, preparing the uterine lining for potential pregnancy.
When exogenous testosterone is introduced, it interferes with this hormonal feedback loop by suppressing the hypothalamic-pituitary-gonadal (HPG) axis. High levels of testosterone reduce the secretion of GnRH, FSH, and LH from the hypothalamus and pituitary. This suppression leads to a significant decrease in ovarian estrogen and progesterone production, preventing normal follicular development and ovulation. The absence of ovulation and the subsequent lack of uterine lining buildup results in amenorrhea, or the cessation of menstruation.
Clinical Applications and Expected Timeline
Testosterone therapy is primarily used to stop periods in the context of gender-affirming care for transgender men and non-binary individuals seeking masculinization. This cessation helps alleviate gender dysphoria for many. Testosterone might also be considered for menstrual suppression in cases of severe endometriosis or heavy menstrual bleeding that have not responded to other treatments, though its masculinizing effects mean it is not typically used for cisgender women.
The timeline for menstrual cessation can vary among individuals. Most people experience their periods stopping within the first six months of starting testosterone therapy. Studies indicate that approximately 75% of individuals achieve amenorrhea within this timeframe. However, for about 25% of people, it may take longer than six months for periods to cease entirely, and some may experience occasional spotting or breakthrough bleeding even after prolonged use.
Broader Effects and Health Considerations of Testosterone Therapy
While period cessation is a notable effect, testosterone therapy induces a range of other physical changes throughout the body. Individuals experience voice deepening due to vocal cord thickening. Increased facial and body hair growth, including on the chest, back, and arms, is common, along with potential male-pattern baldness. The skin often becomes thicker and oilier, which can lead to acne, particularly in the first year of treatment.
Other changes include a redistribution of body fat, with a decrease around the hips and thighs and a potential increase around the abdomen, contributing to a more masculine physique. Muscle mass and strength increase. Individuals may experience increased sweating, altered body odor, and changes in libido. Health considerations with testosterone therapy include potential impacts on cholesterol levels, an increase in red blood cell count, and a possible worsening of sleep apnea. Regular medical supervision and monitoring are important to manage these potential effects and ensure safe use.
Reversibility and Long-Term Management
If testosterone therapy is discontinued, menstrual periods resume, although the exact timeframe can vary. This indicates the body’s natural hormonal cycle re-establishes. While some changes are reversible, others induced by testosterone therapy are permanent.
Permanent changes include voice deepening, clitoral growth, and the development of facial and body hair. Male-pattern baldness, if it occurs, is irreversible. However, effects such as increased muscle mass, changes in fat distribution, skin oiliness, and menstrual suppression are largely reversible upon stopping treatment. Ongoing medical consultation is important for individuals both during and after testosterone therapy to ensure proper health management and to discuss any concerns related to long-term effects or the resumption of menstruation.