For transgendered individuals, the start of hormone therapy can be exciting and anxiety-provoking. Because a trans man's genetic gender does not match his brain gender, testosterone therapy is administered to help masculinize his body. When a man born female begins taking testosterone, he goes through something similar to male puberty.
Method of Administration
According to the Transgender Health Program of Vancouver Coastal Health, the method by which testosterone is administered can affect the rapidity and extent of biological change. Delivery can be intramuscular, or injected; transdermal, or delivered by patch or cream; or oral, taken in pill form. Transdermal administration produces the same degree of masculinization as injection, but may take longer to stop menstrual periods and stimulate growth of facial and body hair. Testosterone taken orally may not be fully effective in stopping menstruation.
Months 1 to 3
In the first three months after starting testosterone therapy, the sex drive tends to increase. The vagina becomes drier, and the size of the clitoris typically increases by one to three centimeters. Facial and chest hair begins to grow, and arm and leg hair becomes thicker and more coarse. Upper body strength and muscle mass increase. Body fat begins to redistribute from the hips to the waist, creating a more masculine shape. Increased production of sebum and acne outbreaks are common.
Months 3 to 6
The menstrual period generally ceases by the sixth month of testosterone therapy. After the third month, the voice begins to change, cracking and deepening like an adolescent boy's. Muscle mass in the chest increases and fat in the breasts decreases, although the breasts may not disappear completely. The degree of chest masculinization depends on the size of the breasts at the time of starting therapy. Many FTMs choose to have breast reduction, or "top surgery," to make the chest appear fully male.
One Year and Beyond
Full growth of facial hair requires one to four years. After a year on testosterone, loss of head hair, or male-pattern balding, may begin to occur. Voice pitch drops to "male" levels. Abdominal weight gain may occur. The clitoris continues to grow, reaching up to 5 cm when fully erect. The feet may grow, and muscle mass and upper body strength continue to increase. The scent of urine and body odors may change.
Side Effects of Testosterone
Testosterone therapy can have significant physical and emotional side effects. Mood swings and increased anger are frequently reported. Because testosterone is metabolized by the liver, regular blood tests for liver function are important. The ovaries cease estrogen production in the presence of testosterone, so osteoporosis is a risk. Increased appetite can lead to weight gain, a particular concern for those who have not yet undergone top surgery, as excess fat deposited in the breasts can make mastectomy more difficult.