: What happens to a woman if she takes testosterone? 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

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.

---