Hair Loss Medications
Currently, the only medications that are scientifically proven to be effective for hair loss treatment and approved by the US FDA are Finasteride (Propecia), a potent oral medication, and a topical agent Minoxidil (Rogaine).
The third medication, dutasteride (Avodart), is in clinical trials. It is similar to finasteride in action and has been approved in Europe for use in hair growth and is sometimes prescribed “off-label” for that purpose in the US. In the US dutasteride (Avodart) is licensed for the treatment of benign prostatic hypertrophy (prostate enlargement) in men.
Of the hair that is lost because of androgenic alopecia, hair on the vertex of the scalp is most likely to be regrown. Regrowing hair on the anterior scalp or restoring hairline is much more difficult.
Note: There is evidence, that hair loss treatment success rate is enhanced by combining the two drugs acting on different aetiological aspects of alopecia11.
Finasteride belongs to the class of medications called type II 5-alpha reductase inhibitors. Finasteride slows the progression of hair loss and stimulates hair growth in parts of the scalp, where hairs are thin. Finasteride is unlikely to grow hair in areas that are completely bald.
In a large 5-year study4, 65% of men with mild to moderate alopecia had increases in hair count. And in nearly all men (90%) treated with finasteride for 5 years, the progression of hair loss was slowed.
How Finasteride (Propecia) works
Finasteride inhibits conversion of testosterone to dihydrotestosterone, causing dihydrotestosterone levels to decrease. Dihydrotestosterone (DHT) contributes to shortening of the growth phase of the hair and to hair thinning.
Problems and concerns
Finasteride may bring on persistent sexual problems, including decreased libido (sex drive), erectile dysfunction, male breast enlargement.
Finasteride can be used only in men. The drug has not been proved effective in women and is not approved for women by the US FDA. Women who are or may become pregnant should not take or handle crushed or broken tablets, because finasteride can cause birth defects.
Finasteride is effective only for as long as it is taken. If you stop taking the drug, you are likely to lose the hair you have gained within 9 to 12 months. It is important to remember that when finasteride is discontinued, you only lose the hair that was gained by the medication, not more. As a result, you will return to the pretreatment level of balding.
Minoxidil (Rogaine) is a topical over-the-counter medication, available as 2% or 5% solution. Minoxidil is indicated for the treatment of hair loss (androgenetic alopecia) in both men and women, however the use of 5% solution is indicated for men only. The use of 5% minoxidil by women is contraindicated due to possible facial hair growth.
Minoxidil stimulates new hair growth and helps stop the loss of hair. The medication is moderately effective and when used correctly, 2% minoxidil has been shown to stimulate hair growth in about 30% of men, with a slightly higher rate in women3. Regrowth is more pronounced at the vertex than in the frontal areas and is not noted for at least 4 months.
How Minoxidil (Rogaine) works
The hair growth properties of minoxidil were an accidental discovery. Minoxidil was originally developed as a medication to lower blood pressure by vasodilation (dilating blood vessels).
How exactly minoxidil promotes hair regrowth is not well understood. Minoxidil appears to increase blood supply to the hair follicles, prolong the anagen phase of hair growth cycle, and increase hair follicle size2.
Problems and concerns
The main problem with Minoxidil is the need for its continual regular application. If you stop using minoxidil, all regrown hair will gradually be lost, and the scalp will most likely get back to the pretreatment balding pattern.
Occasionally application of minoxidil can result in growth of unwanted hair on the face and other parts of the body.
Despite its safety, the efficacy of minoxidil is relatively low at 30-40%.
Ongoing studies are investigating dutasteride (Avodart) in balding men1. Physicians in the U.S. sometimes prescribe Avodart “off-label” for male pattern hair loss.
Dutasteride works in the same way as finasteride (Propecia) to reverse hair loss by inhibiting the conversion testosterone into dihydrotestosterone (DHT). However, unlike finasteride, dutasteride inhibits both type I and type II 5-a reductase isoenzymes. Studies show that dutasteride is superior to finasteride in treating androgenetic alopecia5, but it has yet to be approved by the FDA. Recent 2014 high quality clinical study has demonstrated that dutasteride can significantly increase hair count and width and improve hair growth6.
Latanoprost is a prostaglandin analogue which has been recently investigated as a treatment for androgenic alopecia7. Study revealed that latanoprost may stimulate hair follicle activity and increased hair density.
Bimatoprost, another prostaglandin analogue, is approved for the treatment of eyelash growth. Bimatoprost is also being investigated for its hair growth promoting potential8.
Ketoconazole, an imidazole anti-fungal medication, is effective for the treatment of seborrheic dermatitis and dandruff, and its action on scalp microflora may benefit persons with androgenic alopecia accompanied with follicular inflammation. Studies have demonstrated that topical ketoconazole produces a stimulatory effect on hair growth in animals10 and has a clinically therapeutic effect on androgenetic alopecia9.
Ketoconazole 2% shampoo may be used as an adjunct to finasteride (Propecia) treatment.