Minoxidil has been used in the treatment of androgenetic alopecia (male pattern baldness) for several years. It was first licensed for use as an over-the-counter medication in 1997, since when it has become a widely used remedy for hair loss. Minoxidil was first indicated for use in the treatment of baldness when it was observed that oral administration of the drug in the treatment of hypertension caused excessive hair growth as a side effect.
Minoxidil is effective in causing hair growth
A number of studies published in the late 1980s suggested that topical application of the drug in the form of a solution was effective in promoting regrowth of hair in patients suffering from male pattern baldness. For example, Reitschel and Duncan (1987) found that use of minoxidil caused visible hair regrowth in 89 of the 102 subjects, with 33 subjects demonstrating dense hair growth.
Higher concentrations enhance efficacy
A randomized double-blind placebo-controlled trial published by Olsen et al (2002) found that 5% solutions of minoxidil were significantly superior to placebo, and to solutions containing a lower concentration of the active ingredient. However, these high-concentration solutions have been associated with an increased incidence of skin irritation, thought to be due to the elevated levels of the potential irritant propylene glycol. Higher levels of propylene glycol are necessary in the stronger formulation in order to ensure the solubility of the active ingredient. Residue and stickiness have also been reported by patients using minoxidil solutions, and the formulation is relatively slow to dry, which can be an inconvenience for some users.
New foam formulation reduces risk of contact dermatitis
A new foam formulation for the application of minoxidil was first developed in 2006, but has only recently been introduced in the UK as Regaine® Extra Strength Foam. The foam delivery vehicle is considered to be superior to existing minoxidil solutions as it does not contain propylene glycol which can cause contact dermatitis in some patients (Dermatologic Therapy, 2006). The foam formulation was also rated higher than the solution for a number of attributes including ease of use, lack of dripping and quick absorption and drying in consumer use studies (Olsen et al, 2007).
A double-blind, placebo-controlled trial of the foam by Olsen et al (2007) found that the group of men treated with 5% minoxidil showed a mean 13.4% increase in target area hair count (TAHC) over the 16 week trial; a significantly higher increase than the 3.4% observed in the placebo group. This study suggests that the foam is a successful means of delivering the drug. The researchers also collected safety evidence in an extended 52 week trial and found the incidence of skin irritation to be significantly less for the foam than for 5% minoxidil solutions assessed in a separate trial.
Sources
RL Reitschel, SH Duncan “Safety and Efficacy of Topical Minoxidil in the Management of Androgenetic Alopecia” Journal of the American Academy of Dermatology 16: 677-685 (1987)
EA Olsen, FE Dunlap, T Funicella “A Randomized Clinical Trial of 5% Topical Minoxidil Versus 2% Topical Minoxidil and Placebo in the Treatment of Androgenetic Alopecia in Men” Journal of the American Academy of Dermatology 47:377-385 (2002)
EA Olsen, D Whiting, W Bergfeld “A Multicenter, Randomized, Placebo-Controlled, Double-Blind Clinical Trial of a Novel Formulation of 5% Monoxidil Topical Foam Versus Placebo in the Treatment of Androgenetic Alopecia in Men” Journal of the American Academy of Dermatology 57:767-774 (2007)
D McNamara “Minoxidil Foam Promises Efficacy, More Patient Satisfaction” Dermatologic Therapy March 2006
Veronica Mitchell - Veronica studied veterinary medicine at Cambridge University before becoming a secondary school science teacher. She enjoys writing about ...
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