Why does teenage girls have moustaches?

Women with mustachesSome women may have hereditary traits from their parents. Some women may have shaved it for a better appearance. Once the hair is cut, it toughens and thickens, which may cause a woman to look like she has a mustache. (Shaving doesn't toughen & thicken hair: Why it may seem to: 1/Shaved hair has has a blunt end, not a naturally tapered end. 2/Once you begin shaving, you're likely to shave again when the hair grows in only a fraction of an inch: Very short hair is stiff,(stubble). Switch to tweezing: Hair will grow in as tender & thin as it ever was.) AnswerWomen have mustaches for hereditary reasons as stated above, but more specifically because of hormone levels. If a woman takes testosterone orally or it is absorbed through the skin she will grow facial hair and undergo other superficial physical changes (voice will deepen etc), and if a man takes estrogen he will grow breasts, his voice will become lighter etc.

When they stop taking the hormones their appearance will go back to normal - there have been instances of men in south America growing breasts due to hormones in chicken, and men getting estrogen from having sex with their wives after using some femenine hygene products with estrogen and other hormones in them.
Because the individual in question has just a little bit extra testosterone in her system.