The primary connection between progesterone and hair loss is that a lack of progesterone can cause an increase in male hormones in women and lead to pattern baldness. Another link between the two is that significant drops in progesterone occur during and after menopause for many women, and this is also the time when hair loss increases dramatically, although the two are not always directly linked. Indirectly, lowered progesterone levels can make the body more susceptible for other triggers of hair loss, such as raised testosterone levels and thyroid dysfunction.
Menopausal and post-menopausal women are most at risk for hair loss, which is sometimes cause by a marked decline in progesterone. When this occurs, larger amounts of certain steroid hormones normally produced by men in high quantities begin to be manufactured. This is what can lead to a deeper voice and increased hair on the face or arms, while also leading to symptoms like male pattern baldness. This is much rarer for women than for men, but it does occur often enough for pharmaceutical companies to prepare specialized formulations for hair regrowth tailored for women.
In this way, progesterone and hair loss are linked because lowered female hormone levels are the cause of the spike in male hormone levels. Sometimes taking a progesterone supplement in the form of injections, natural hormone suppositories, or capsules may help prevent further hair loss and promote hair growth. Other symptoms of menopause may also be alleviated, depending on type and dosage.
Progesterone and hair loss are also indirectly linked because during the time when most women experience a drop in progesterone, other issues may arise to lead to thinning hair. For instance, one of the main causes of hair loss is thyroid dysfunction. They thyroid gland controls many bodily functions, so when it is not working correctly, side effects can be extreme. Sometimes thyroid problems can lead to a drop in progesterone even in women in their childbearing years, leading to the same issues mentioned previously.
Thyroid problems are more often diagnosed in menopausal women, and they may be exacerbated by the already dramatic changes happening in the body. This can lead to hair loss as well, with or without being directly linked to progesterone levels. Taking medications to improve function of the thyroid gland may help.
Another common link between progesterone and hair loss occurs in pregnant or postpartum women. During pregnancy, many women develop thicker hair that is healthier than before pregnancy. This is possibly caused by the higher levels of progesterone being produced. After delivery, the extra hair can begin to fall out quickly. In most cases, this is a temporary condition and does not lead to long-term bald spots or true pattern baldness.