Hair loss or hair thinning is a common source of anxiety for many women. The hair on our head is our most visible secondary sexual characteristic and its purpose is almost purely aesthetic. Long, thick hair in women has long been equated with beauty and femininity. It is therefore not surprising that hair loss in women can have more significant psychosocial consequences than it does in men.
Female pattern hair loss is more common than you think, with the incidence estimated to be around 20%. Whilst it often occurs in postmenopausal women, it can occur as early as puberty and quite commonly begins in the early 20s.
Unlike in men, total baldness and a receding hairline are uncommon in women. Women will usually notice a widening part or smaller ponytail before they notice visible shedding or thinning. This is because hair loss in women is usually a result of hairs shrinking in terminal length and diameter rather than a decrease in total hair follicle numbers. Hair loss is usually incomplete, resulting in thin hair with visible areas of sparsely covered scalp in between. The areas most commonly affected are the front and vertex of the scalp.
There are a multitude of causes for hair loss in women including severe emotional or physical stress, certain medications and hypothyroidism. However, the majority of hair loss or thinning is genetic and results from a process known as follicular miniaturisation. This occurs when the ratio of terminal, or fully mature hair follicles, to thin, immature hair follicles falls. The mechanism by which this occurs isn’t completely clear although it is probably a mix of genetic and hormonal factors.
An important and under diagnosed cause of poor hair health in women is malnutrition, often as a result of anorexia nervosa or bulimia. In an underweight woman who notices hair thinning or loss, the presence of an eating disorder should always be considered.
Whilst male pattern hair loss is primarily driven by the androgenic hormone dihydrotestosterone (DHT), the role this hormone plays in female pattern hair loss remains uncertain. Certainly the majority of women who experience hair loss have normal levels of DHT.
Nevertheless female pattern hair loss can sometimes be due to androgen excess. Certain conditions, including polycystic ovarian syndrome and adrenal gland dysfunction which lead to androgen excess, also result in hair loss. Typically women in whom hair loss is due to androgen excess will have other signs of androgen excess including menstrual irregularities and abnormal hair growth elsewhere.
Research has shown that whilst hair loss is usually perceived by the individual to be worse than it is, it is often associated with psychosocial distress, poor body image, and low self esteem. For this reason alone, it is important to see your general practitioner if you think you have started to lose your hair.
But that’s not the only reason to visit your doctor. As previously mentioned, female pattern hair loss may be a symptom of other medical conditions. It is important to exclude these. Rarely, garden variety female pattern hair loss can be confused with other primary hair and scalp conditions which require a different treatment approach. These conditions can usually be differentiated by your general practitioner or dermatologist based on history and examination.
The most common primary hair and scalp condition leading to hair loss is known as Telogen Effluvium. This may be difficult to differentiate from female pattern hair loss, but is usually preceded by an extreme stressor and occurs diffusely over the scalp. Female pattern hair loss in contrast typically occurs over the front of the scalp or scalp vertex. Alopecia Areata is an autoimmune condition which results in patchy hair loss. However, it can also occur diffusely or in a variety of patterns resembling female pattern hair loss. This too should be excluded.
There is no panacea for female pattern hair loss. However, there are a variety of treatment options. All of them require patience as they must be adhered to for a prolonged period to notice any result. The response to treatment is variable and is usually more effective the earlier it is initiated.
The first line treatment for female pattern hair loss is topical Minoxidil which can be applied to the scalp as either a lotion or foam. Minoxidil works by enlarging miniaturised hair follicles although its exact mechanism of action is not known. Minoxidil is not a quick fix. It takes at least three months to start working, and it should be trialed for at least 12 months before deeming it ineffective. A degree of hair shedding usually occurs after starting Minoxidil before any noticeable hair regrowth is seen. Anecdotally, a lot of leading dermatologists are now prescribing oral Minoxidil for hair loss, but at this stage, good evidence to support this is limited.
For women who either don’t respond to Minoxidil, or who suffer hair loss due to androgen excess, there are other treatment options. In Australia, the most common next line treatments are Spironolactone and Cyproterone acetate.
Spironolactone and Cyproterone acetate exert an antiandrogen effect by altering both androgen production and androgen receptors. Some studies have shown that when used for a sustained period they can result in hair regrowth for many women. Other studies have shown that they have little effect and a significant proportion of women do not respond. Still, they are relatively safe, with few side effects. They should however be avoided in women looking to fall pregnant.
Saw Palmetto is a naturally occurring substance which may exert a similar selective anti androgenic effect. Again, there is little data to support this but it is certainly a low risk option.