Interventions For Female Pattern Hair Loss
The most common type of hair loss in women is female pattern hair loss, also known as androgenic alopecia. Unlike men, they do not go bald, but have hair thinning predominantly over the top and front of the head. It can occur at any time, from puberty until later in life. However, it occurs more frequently in postmenopausal women.
The diagnosis is supported by careful history taking (including family history). Other causes should be considered; therefore, a clinical examination and laboratory tests may be necessary. Female pattern hair loss can have a significant impact on self-consciousness, and the damage to a woman's self-confidence can affect her quality of life, leading to feelings of unattractiveness, shame, discomfort, emotional stress, and low self-esteem. This review was needed to clarify the best approach to treat this condition and provide reliable decision-making information for women and clinicians.
Twenty two studies, comprising 2349 women, were included. More than half of the studies were assessed as high risk of bias, and the rest, unclear risk of bias. Industry sponsorship represented a potential source of bias in six of the included studies.
This review found that minoxidil is more effective than placebo. In four studies, the proportion of women that experienced at least moderate hair regrowth was twice as high in the minoxidil group compared to the placebo group. In seven studies (including the four just mentioned), there was an important increase in total hair count per cm² in the minoxidil group compared to the placebo group. Except for an increase in adverse events with minoxidil 5% twice daily, the number was similar for both groups. The adverse events were mostly mild, consisting of itch, skin irritation, dermatitis, and additional hair growth on areas other than the scalp. Minoxidil should not be used in pregnant or lactating women. Most of the other interventions and comparisons were covered in single studies, which were assessed as high risk of bias, did not address our outcomes, or both. Therefore, no firm conclusions can be made about their efficacy or safety.
Although it is generally acknowledged that renewed hair shedding occurs relatively soon after discontinuation of treatment, none of the studies reported data on the sustainability of the treatment effect, nor on the possible impact of hair regrowth, reflected by a decrease in time spent by the women on hair styling or the use of wigs.
Future research should aim to provide evidence for people to make informed decisions about whether these treatments are effective, and whether the effects are sustainable after discontinuation of treatment.
van Zuuren EJ, Fedorowicz Z, Carter B, Andriolo RB, Schoones J. Interventions for female pattern hair loss. Cochrane Database Syst Rev 2012;5:CD007628. www.thecochranelibrary.com/details/file/2052235/CD007628.html [pdf]
BACKGROUND: Female pattern hair loss, or androgenic alopecia, is the most common type of hair loss affecting women. It is characterised by progressive shortening of the duration of the growth phase of the hair with successive hair cycles, and progressive follicular miniaturisation with conversion of terminal to vellus hair follicles (terminal hairs are thicker and longer, while vellus hairs are soft, fine, and short). The frontal hair line may or may not be preserved. Hair loss can have a serious psychological impact on people.
OBJECTIVES: To determine the effectiveness and safety of the available options for the treatment of female pattern hair loss in women.
SEARCH METHODS: We searched the following databases up to October 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2011, Issue 4), MEDLINE (from 1946), EMBASE (from 1974), PsycINFO (from 1806), AMED (from 1985), LILACS (from 1982), PubMed (from 1947), Web of Science (from 1945), and reference lists of articles. We also searched several online trials registries for ongoing trials.
SELECTION CRITERIA: Randomised controlled trials that assessed the effectiveness of interventions for female pattern hair loss in women.
DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data.
MAIN RESULTS: Twenty two trials, comprising 2349 participants, were included. A wide range of interventions were evaluated, with 10 studies investigating the different concentrations of minoxidil. Pooled data from 4 studies indicated that a greater proportion of participants (121/488) treated with minoxidil reported a moderate increase in their hair regrowth when compared with placebo (64/476) (risk ratio (RR) = 1.86, 95% confidence interval (CI) 1.42 to 2.43). In 7 studies, there was an important increase of 13.28 in total hair count per cm(2) in the minoxidil group compared to the placebo group (95% CI 10.89 to 15.68). There was no difference in the number of adverse events in the twice daily minoxidil and placebo intervention groups, with the exception of a reported increase of adverse events (additional hair growth on areas other than the scalp) with minoxidil (5%) twice daily. Most of the other comparisons consisted of single studies. These were assessed as high risk of bias: They did not address our prespecified outcomes and provided limited evidence of either the efficacy or safety of these interventions.
AUTHORS' CONCLUSIONS: Although more than half of the included studies were assessed as being at high risk of bias, and the rest at unclear, there was evidence to support the effectiveness and safety of topical minoxidil in the treatment of female pattern hair loss. Further direct comparison studies of minoxidil 5% applied once a day, which could improve adherence when compared to minoxidil 2% twice daily, are still required. Consideration should also be given to conducting additional well-designed, adequately-powered randomised controlled trials investigating several of the other treatment options.
