Hair loss affects more than 50% of men and this increases up to 73% over the age of 80. An equally large proportion of women suffer with hair thinning postmenopausally. At Rejuvence Clinic we specialise in the treatment of hair loss with a particular interest in the use of platelet rich plasma (PRP) for the treatment of male and female pattern hair loss. However, as with the majority of hair loss treatments, combinations provide quicker and longer lasting results than monotherapy.
Hair Cycle and Androgenetic Alopecia
The typical hair cycle consists of three states – anagen (active growth phase in which follicles remain for up to 6-7 years), catagen (short 2 week transition phase that heralds the end of the growth phase and follicles prepare for resting state) and telogen (resting phase of the hair follicle and normally lasts a few months at which hairs can be shed). Disruption of the hair cycle including a disproportionate large number of hairs in telogen phase as well as shortening of the anagen phase can result in noticeable hair loss and hair thinning and underpins the majority of hair loss conditions.
Medical treatment for hair loss is relatively well established. Prior to starting any medication for hair loss it is essential to establish an underlying diagnosis and cause. In the majority of cases this will normally be male or female pattern hair loss, otherwise known as androgenetic alopecia. However, other causes of hair loss include acute and chronic telogen effluvium, alopecia areata (including totalis and universalis), traction alopecia and more rare conditions such as lichen plano plinaris.
Androgenetic alopecia accounts for the majority of hair loss sufferers. Androgenetic alopecia is the result of large circulating levels of dihydrotestosterone (DHT) following conversion of testosterone by the enzyme 5-alpha reductase. Simplistically put, dihydrotestosterone (DHT) reduces the active blood supply to the scalp and subsequently susceptible hairs start to miniaturise and spend shorter periods of time in the anagen phase. Strong hairs are converted to vellus hairs and eventually lost altogether. Those individuals lucky enough to lack the gene responsible for the production of 5-alpha reductase tend to hold on to their hair for much longer.
Whilst assessing hair loss an initial set of blood tests can be very helpful, particularly in the assessment of female sufferers. A typical female hair-loss evaluation should include:
- Full blood count – check for haemoglobin levels and evidence of anaemia
- Serum iron levels – check for iron deficiency anaemia
- Thyroid Function Tests – check for evidence of underactive thyroid (hypothyroidism)
- Erythrocyte Sedimentation Rate – check for inflammatory conditions
- Male/Female hormone levels – testosterone/DHEAS
Correction of simple conditions such as iron deficiency anaemia and/or hypothyroidism can help significantly improve hair loss and encourage recovery of previous hair density. An oestrogen rich state in women, for example whilst pregnant or if taking the oral contraceptive pill can encourage longer anagen (growth) phase within the hair cycle. As a result once a woman gives birth or comes off the pill there can be a synchronous transition of a large proportion of hairs into telogen phase and a widespread shedding. This can be quite alarming but is normally temporary and hair thickness and density is restored once hair cycle has readjusted.
Minoxidil – 5% or 2%
As is clear from above, there are a number of common conditions and causes of hair loss and thinning that can very easily be identified and corrected and prevent the need to pursue specific medical treatments. At Rejuvence Clinic we are always insistent on recording an accurate medical history and keen to exclude conditions such as iron deficiency anaemia and hypothyroidism before embarking on long term treatments that require dedication and commitment.
There are two FDA approved medications for use in androgenetic alopecia – minoxidil and finasteride. A common theme amongst medical treatments for alopecia is that the majority of them have been stumbled upon inadvertently. Minoxidil was originally developed to be taken orally for the treatment of hypertension (high blood pressure). Whilst on treatments many patients noticed accelerated hair growth on their scalp and body. This resulted in the development of a topical form of minoxidil to be applied to the scalp. At present there are two formulations available – 2% and 5%. Minoxidil 5% twice a day is approved in males and 2% for females although many advocate the use of 5% strength in women.
The mechanism of action of minoxidil is not fully understood. Numerous researchers have identified a number of attributes that likely contribute to its success:
- Minoxidil has been shown to increase the blood supply to the scalp. A more rich scalp blood supply helps to stave off the effects of DHT in androgenetic alopecia.
- Minoxidil stimulates vascular endothelial growth factor – a growth factor that aids follicle growth.
- Minoxidil increases angiogenesis – the process of growing new blood vessels.
- Minoxidil increases cell proliferation and DNA synthesis.
- Minoxidil actively shortens the telogen phase meaning hairs remain in anagen for longer and hence less likely to miniaturise.
Dr Areej Adil and Dr Marshall Godwin published a review of the effectiveness of treatments for androgenetic alopecia in the Journal of the American Academy of Dermatologists in February of this year. They pooled the results of 23 high quality and well conducted randomised controlled trials to assess the effectiveness of 5% minoxidil in men, 2% minoxidil in men and 2% minoxidil in women. A meta-analysis of the data pooled from these studies demonstrated a significant improvement in androgenetic alopecia for all these groups, especially for men using 5% minoxidil as opposed to 2% strength in male and females. Effects of minoxidil are not visible for at least 6-9 months of use. Side effects associated with minoxidil are limited. Older formulations were associated with excessive drying of the scalp and possible dermatitis. It is important to note, however, that cessation of treatment with minoxidil can result in increased shedding.
Finasteride AKA Propecia – Does it have sexual side effects?
Finasteride, popularly known and marketed by Merck as ‘Propecia’, has been extensively used in the treatment of androgenetic alopecia. Finasteride and its hair growth properties were also stumbled upon by chance whilst being used for the treatment of benign prostatic hypertrophy (enlarged prostate) in males. Although, not licensed for use in androgenetic alopecia by the drug manufacturer, it has been used in 1mg formulation and 5mg formulation in males suffering with male pattern hair loss. Finasteride effectively inhibits the action of type II 5-alpha reductase and hence reduces the conversion of testosterone to DHT. Subsequently circulating DHT levels are reduced and hence there is a reduction in hair thinning and shedding. Finasteride has been shown to reduce circulating levels of DHT by 65%.
Adil and Godwin, in their systematic review and meta-analysis of treatments for androgenetic alopecia, pooled data from 4 well conducted randomised controlled trials and demonstrated a significant improvement in androgenetic alopecia following treatment with 1mg finasteride once daily.
There is a large amount of negative publicity associated with finasteride regarding its side effects pertaining to men. The majority of side effects are associated with varying forms of sexual dysfunction. FDA phase III trials identified decreased libido, erectile dysfunction, ejaculation disorders and decreased ejaculate volume as side effects that may be associated with use of finasteride. This all sounds quite concerning, however, it important to keep this in perspective. This same phase III FDA trial compared the effects of finasteride and a placebo on the above list of side effects. The table below lists the percentage of users afflicted with these side effects:
| Number (%) of patients with: | Finasteride 1mg OD | Placebo |
| Decreased libido | 1.8% | 1.3% |
| Erectile dysfunction | 1.3% | 0.7% |
| Ejaculation disorder | 1.2% | 0.7% |
| Decreased ejaculate volume | 0.8% | 0.4% |
When all sexual dysfunctional side effects are pooled together there was 3.8% increased risk of such side effects occurring following use of finasteride as opposed to 2.1% risk in using placebo. Despite being significant it is a very low proportion of men who would potentially suffer from any sexual dysfunction. Side effects are, on the whole, identified early after starting use and resolve rapidly in the vast majority of men following cessation of use. However, there are a very small number of men who suffer with Post-Finasteride Syndrome – suffer with sexual side effects for more than 3 months after stopping use.
Finasteride cannot be prescribed to women of childbearing age. This is because it has been shown to be teratogenic to the male fetus. It is therefore, absolutely contraindicated in premenopausal women. However, men taking finasteride can father children and there is no risk of endangering the fetus. Finasteride can be used in postmenopausal women and there is some limited evidence to show that if combined with minoxidil it can a positive effect on hair loss. More recently there has been increased attention and focus on a drug called dutasteride. This is similar to finasteride and is a recognised Type I and Type II 5-alpha reductase blocked as opposed to just Type II as is the case for finasteride. Total circulating DHT is the product of both Type I and Type II 5-alpha reductase and Type II 5-alpha reductase accounts for 30% of DHT. Indeed 0.5mg of dutasteride has been shown to reduce DHT levels by more than 90% as opposed to just 65% in 1mg of finasteride. However, there is a significantly increased incidence of sexual side effects and they tend to last for longer after stopping treatment.
Spironolactone – an alternative for premenopausal women
Spironolactone has been identified and used, with relative success, in females suffering with androgenetic alopecia. This is especially the case with women of childbearing age, due to the contraindications associated with finasteride. It can be used at a dose of 50mg – 100mg daily in mild to moderate hair loss and up to 200mg daily in severe hair loss. However, it is important to monitor actively potassium levels, avoid potassium rich foods and also ensure patients are not taking certain other drugs including specific blood pressure tablets (ACE inhibitors) and antidepressants (SSRIs). In the event of a woman becoming pregnant spironolactone does need to be stopped as it has been shown to have harmful effects to the male fetus.
In conclusion
In the main medical treatment is the start of a long and difficult road to treatment hair loss and specifically androgenetic alopecia. It is only the first step. It is important to understand it does have a place in hair loss treatments and particularly in combination can be very helpful with encouraging results. The effects of medical treatment:
- Will preserve the status quo – hair is maintained and the progression of hair loss diminished. In many cases this is defined as being a successful and positive outcome.
- Can increase hair volume – fine vellus and miniaturised hairs will revert to thicker terminal hairs.
- Can increase hair count – fewer hairs going into telogen phase and hence fewer hairs falling out.