Unit – 2.8b – Influences on hair growth rate

Normal endocrine influences on patterns of hair growth 

The endocrine system is a collection of glands that produce hormones that regulate the body’s growth, metabolism, sexual development and function and hair growth.  The hormones are released into the bloodstream and transported to tissues and organs throughout the body. 

The influences of the endocrine system that produce unwanted hair growth may be may be abnormal such as disease, medication and surgery.  Normal, predictable systemic endocrine conditions include puberty, pregnancy and menopause. 


While influencing the development of the secondary sexual characteristics in both males and females, rising hormone levels can cause acne and skin blemishes.  Where the hormone balance is delicate, taking the contraceptive pill to regulate menstruation and improve bad complexions can result in excessive hair growth.  Eighteen is considered to be the minimum age for undergoing laser and IPL treatments, although with parental consent this can be lowered. In this case it would be wise to seek a medical referral. 


Some women need help from drugs to achieve fertility or to maintain the pregnancy and prevent miscarriage.  This can sometimes cause unwanted hair growth. This usually appears after the birth, when there is hormonal build up in the system.  These hairs are often strong and difficult to remove.  After a normal pregnancy excessive hair on the upper lip, chin and cheeks may regress naturally.  However a succession of pregnancies without any gaps can result in permanent hair growth problems.


Following menopause some women experience unwanted hair growth on the upper lip, chin and throat.  This is usually a result of hormone changes and is part of ageing, along with pigmentation marks and fibrous lumps.  As the oestrogen declines it loses control over the pituitary hormones and this results in an excess of hair-producing androgens. Oestrogen replacement may provide some assistance in controlling hair growth.  Hair growth seldom appears after menopause, so treatment started late in menopause should be successful.  The most common pattern is two tufts of hair on either side of the chin which over time may join together.