Hair Restoration Medications: A Summary at a Glance

Minoxidil is offered in 2% and 5% concentrations. The 5% concentration was developed for treatment of male-pattern hair loss, but studies have shown that women also can benefit from the 5% formula.(2)

Availability
Over-the-counter. Generic minoxidil is also offered under a variety of trade names; it may also be an ingredient in an over-the-counter product.

Rogaine is the brand name for minoxidil before its patent expired and generic versions could be developed.

Mode of Action
How minoxidil acts to slow hair loss and stimulate hair regrowth is not well understood. Minoxidil was first developed as an oral medication to lower blood pressure by dilating blood vessels. Its activity in stimulating hair growth was noted as a side effect. The side effect on hair growth became the basis for development of the hair restoration product Rogaine. Whether minoxidil’s effect in dilating blood vessels contributes to its effect on hair growth is not known.

Effectiveness
Studies have shown that minoxidil slows or halts hair loss and promotes hair regrowth in both men and women, at both 2% and 5% formulations. The 5% formulation is generally more effective. (3)Positive response to minoxidil therapy (reduced hair loss and/or hair regrowth) has been noted in from less to 50% to more than 80% of persons treated in various studies. Positive response is lost if minoxidil therapy is discontinued. Minoxidil is more effective when applied to defined areas of hair loss, less effective when applied to large areas of hair loss.

Side Effects
Itchy scalp is the most common side effect of minoxidil therapy. Accidental application of minoxidil to the face can result in growth of unwanted facial hair. Repeated, large applications of minoxidil have been associated with a drop in blood pressure in a few reported cases.

The 1 milligram dose is for treatment of male-pattern hair loss. Under the brand name Proscar, a 5 milligram dose is given to treat benign prostatic hypertrophy (prostate enlargement) in men.

Availability
By prescription. Finasteride for hair restoration is available under its brand name Propecia.

Mode of Action
Finasteride inhibits the activity of Type II 5-alpha reductase, an enzyme that converts the male hormone testosterone into a more potent form called dihydrotestosterone (DHT). DHT is believed to act on scalp hair follicles to render them inactive and incapable of producing full-grown hair.(2)

Effectiveness
Large, multi-year studies have shown finasteride to reduce hair loss and/or stimulate hair regrowth in a majority of men treated.(3) In a 5-year study, 65% of men with mild to moderate male-pattern hair loss were found to have a positive result (hair loss reduced and/or hair regrowth stimulated). Finasteride therapy must be continued to maintain a positive result. Physician hair restoration specialists may combine minoxidil and finasteride therapy to achieve an optimal result in selected patients. Medical therapy may be combined with surgical hair restoration to achieve and maintain an optimal result.

Side Effects
Finasteride should not be used or handled by a woman who is pregnant or who may become pregnant. The drug can cause abnormal development in a fetus. Reported side effects include decreased libido (sex drive), erectile dysfunction, male breast enlargement and psychological depression.

Dutasteride has not yet been approved for treatment of hair loss. Clinical trials are being conducted.

By prescription. Avodart is approved by the FDA for treatment of benign prostatic hypertrophy (prostatic enlargement) in men. Clinical trials are underway to seek FDA approval of dutasteride for treatment of male-pattern hair loss. It is approved in Europe, at a different dose, for treatment of hair loss. Physicians in the U.S. sometimes prescribe Avodart “off-label” for treatment of male-pattern hair loss, if characteristics of an individual patient warrant such use of the drug.

Mode of Action
Dutasteride, like finasteride, inhibits the activity of the enzyme that converts testosterone into dihydrotestosterone (DHT). Finasteride inhibits Type II of the enzyme 5-alpha reductase; dutasteride inhibits both Type I and Type II of the enzyme.

Effectiveness
In clinical trials reported, dutasteride has shown a profile similar to that of finasteride in treatment of male-pattern hair loss.

Side Effects
As with finasteride, dutasteride should not be taken or handled by a women who is pregnant or who may become pregnant because of the drug’s potential for causing abnormal development of a fetus. Side effects of dutasteride are similar to those reported for finasteride—decreased libido (sex drive), erectile dysfunction, male breast enlargement and psychological depression.

Drug interactions reported from use of dutasteride include interference with some antibiotics, some anti-depression and anti-anxiety medications, and some drugs used to treat HIV/AIDS.