I'm interested in the changes that happen to the female body (let's say this person is 20) in the short (year one to five) and in the long term (20+ years).
Let's assume that the dose of testosterone is high enough to reach the typical levels that a man has.
Are there any studies, especially for the long term changes and effects?
The long-term impact of testosterone on women's health is still not clarified enough, so it's not easy to predict them exactly. Some common side-effects of high testosterone level are acne and increased oiliness of the skin and hair. High level of testosterone con also lead to infertility and are commonly seen in polycystic ovarian syndrome. There're side-effects related to high-dozage intake of testosterone: liver-damage, hirsutism, masculinization.
One of the 20 randomized, placebo-controlled trials examined the risk of liver disease in women receiving androgens and showed no change in hepatic enzymes. In the literature, this has been reported only in cases in which the blood testosterone levels increased to supraphysiological levels.
Other adverse effects of the use of testosterone in women, such as hirsutism, deep voice, and an enlarged clitoris, should not be neglected. However, the most common adverse effects are acne and increased oiliness of the skin and hair, which were also reported in 3 of the studies shown in Table 1. In addition, 10% of patients receiving 1.25 mg/day or 2.5 mg/day of methyltestosterone and 45% of those receiving 10 mg/day of the same were reported to have experienced these side effects.
Masculinization is rare and is due to the administration of high doses of androgens. Implants containing up to 300 µg/day of testosterone initially produce supraphysiological blood peaks, although these are transient and do not induce virilization.
Testosterone intake is connected with some myths and mysconceptions, which was revealed.
Testosterone is a ‘male’ hormone
Testosterone is the most abundant biologically active hormone in women
Testosterone's only role in women is sex drive and libido
Testosterone is essential for women's physical and mental health and wellbeing
Testosterone masculinizes females
Outside of supra-pharmacologic doses of synthetic androgens, testosterone does not have a masculinizing effect on females or female fetuses
Testosterone causes hoarseness and voice changes
There is no conclusive evidence that testosterone therapy causes hoarseness or irreversible vocal cord changes in women
Testosterone causes hair loss
Testosterone therapy increases scalp hair growth in women
Testosterone has adverse effects on the heart
There is substantial evidence that testosterone is cardiac protective and that adequate levels decrease the risk of cardiovascular disease
Testosterone causes liver damage
Non-oral testosterone does not adversely affect the liver or increase clotting factors
Testosterone causes aggression
Testosterone therapy decreases anxiety, irritability and aggression
Testosterone may increase the risk of breast cancer
Testosterone is breast protective and does not increase the risk of breast cancer
The safety of testosterone use in women has not been established
The safety of non-oral testosterone therapy in women is well established, including long-term follow up
Long-term data exists on the efficacy, safety and tolerability of doses of up to 225 mg in up to 40 years of therapy. In addition, long term follow up studies on supra-pharmacologic doses used to ‘female to male’ transgender patients report no increase in mortality, breast cancer, vascular disease or other major health problems
The result of testosterone intake relates of dosages and initial testosterone level. Normal testosterone levels for all women values from 0.26 to 1.3 ng/ml. The rate of free testosterone varies with age, for the age 21-39 it's 0,12-3,1 pg/ml.
