Testosterone Replacement Therapy and Weight Changes in Women
Testosterone replacement therapy in women generally leads to an increase in muscle mass but does not significantly affect overall body weight or cause weight gain.
Effects of Testosterone on Body Composition in Women
Testosterone replacement therapy (TRT) in women affects body composition in several ways:
Women with HIV wasting have low testosterone levels, but testosterone supplementation (150 mg/day) shows some positive effects on muscle mass strength without significant weight gain or muscle mass gain 1.
A meta-analysis of testosterone therapy in HIV patients showed only a minimal difference in weight between testosterone and placebo groups (0.63-1.04 kg), indicating minimal impact on overall weight 1.
In a randomized controlled trial of HIV-infected women with weight loss, physiological testosterone replacement raised testosterone levels but did not significantly increase fat-free mass, body weight, or muscle performance 2.
Testosterone therapy in women may increase skeletal muscle mass without changing body fat, as demonstrated in women with hypopituitarism 3.
Comparison with Estrogen/Progestin Therapy
While testosterone's effects are modest, it's worth comparing to other hormone therapies:
Estrogen and progestin hormone replacement therapy does not cause extra weight gain in menopausal women beyond what is normally gained during menopause 4.
Hormone replacement therapy with estradiol valerate and cyproterone acetate can counteract postmenopausal increases in body weight and body fat, particularly preventing central (android) fat distribution 5.
Continuous estrogen and progestin replacement therapy neither prevents nor increases early postmenopausal weight gain and fat accumulation but does minimize the shift from gynoid to android fat distribution 6.
Testosterone Effects in Men vs. Women
The effects of testosterone differ significantly between men and women:
In men with obesity and hypogonadism, testosterone replacement is associated with weight loss and improvements in metabolic parameters 1.
Men show more pronounced effects from testosterone therapy, including increased lean body mass and decreased fat mass 3.
The anabolic effects of testosterone on muscle are well-established in men but less clear in women 3.
Safety Considerations
When considering testosterone therapy for women, several safety aspects should be noted:
High-density lipoprotein (HDL) cholesterol levels may decrease with testosterone therapy in women 2.
Testosterone therapy is not currently licensed for use in HIV wasting in women in Europe 1.
There are concerns about adverse metabolic effects of long-term testosterone administration in women, requiring careful monitoring 1.
Clinical Implications
For clinicians considering testosterone therapy for women:
Testosterone assessment should be considered in patients with signs and symptoms of hypogonadism, including decreased energy, libido, and muscle mass 1.
Monitoring should include testosterone levels 2-3 months after treatment initiation and after any dose change 1.
The method of testosterone replacement should be selected based on individual patient factors, with transdermal preparations often preferred for convenience 1.
Testosterone therapy in transgender men leads to significant increases in muscle volume (15%), quadriceps cross-sectional area (6%), and muscle strength (12%), which may be relevant when considering effects in cisgender women 1.