How Minoxidil (Rogaine) hair loss medication works?
Minoxidil (Rogaine) is a drug available in two forms to treat different conditions. Oral minoxidil is used to treat high blood pressure and the topical solution form is used to treat hair loss and baldness.
Minoxidil (Rogaine) was the first drug approved by the FDA for the treatment of androgenetic alopecia (hair loss). Before that, minoxidil had been used as vasodilator drug prescribed as oral tablet to treat high blood pressure, with side effects that included hair growth and reversal of male baldness. In the 1980s, UpJohn Corporation came out with a topical solution of 2% minoxidil, called Rogaine, for the specific treatment of androgenetic alopecia. Since the 1990s, numerous generic forms of minoxidil have become available to treat hair loss while the oral form is still used to treat high blood pressure.
The popularity hair loss treatment is due to the general preference in the overall population for the cosmetic appearance of a full head of hair. Minoxidil is used to stimulate hair growth in areas of the scalp that have stopped growing hair. As of early 2001, the exact mechanism of action of minoxidil is not known. Minoxidil is moderately effective and can be helpful for some people. Recently, Rogaine in 5% solution became available and has been reported to be much more effective than the 2% formulation. Some physicians recommend combining finasteride and minoxidil to achieve the best results from medical (non-surgical) treatment of androgenetic alopecia. Your International Society of Hair Restoration Surgery (ISHRS) doctor can discuss this with you during a consultation.
Used as directed, 2% topical minoxidil has been shown to stimulate hair growth in about 30% of male patients, with a slightly higher response rate in female patients. The response rate to 5% topical solution is higher in both men and women [Price VH, Menefee E. Quantitative estimation of hair growth: Comparative changes in hair weight and hair count with 5% and 2% minoxidil, placebo and no treatment. In: van Neste DJJ, Randall VA (eds.) Hair Research for the Next Millennium. Amsterdam: Elsevier Science; 1996:67-71]. Other studies have indicated increased benefit of the 5% solution in women, with increased hair counts in pre-selected target areas of the scalp (Olsen EA. Cited above]. At all formulations, as noted above, women have been shown to have a better response than men to topical minoxidil.
Topical minoxidil (Rogaine) at either 2% or 5% solution is most effective in persons with recent onset of hair loss due to androgenetic alopecia, and relatively small areas of hair loss. Minoxidil is less effective when hair loss is long-standing or large in area. Thus, early use of minoxidil is indicated to prevent progression of small areas of pattern baldness. Topical minoxidil is generally more effective in improving hair growth in central areas of the scalp than in frontal areas. Minoxidil has been shown to be effective in increasing the amount of time that hairs stay in the anagen (growth) phase versus telogen (resting) phase. It has been shown effective in initiating growth of vellus (soft, fine) as well as terminal (long, coarser) hairs. See About hair lossfor full explanation of the phases of hair growth.
When topical minoxidil is first applied, shedding of telogen-phase hairs may be increased for a short time. This loss of telogen-phase hairs is temporary, and the lost telogen hairs will be replaced by new hair over the next weeks and months of minoxidil therapy.
Once started, topical minoxidil treatment for androgenetic alopecia is a lifetime commitment if the treatment proves effective. If regular application of topical minoxidil is halted, all hair grown in response to the therapy will be rapidly lost over the next 3 to 6 months.
Minoxidil can complement and supplement other hair restoration treatments. For example, in a planned approach to hair restoration agreed to by a patient and physician hair restoration specialist, minoxidil may be used to complement hair transplantation or other surgical method such as scalp reduction [Roenigk HH, Jr. Scalp reduction. In: Roenigk & Roenigk’s Dermatologic Surgery, 2nd ed. New York: Marcel Dekker, Inc., 1996:1213-1226]. Minoxidil may be applied to stimulate hair growth inside and/or outside areas of surgical hair restoration, contributing to improved "fullness" of scalp hair. Combined medical treatment of male pattern baldness with minoxidil (Rogaine) and finasteride (Propecia) may be recommended in some instances after examination and diagnosis by a physician hair restoration specialist.
Patients should understand that topical minoxidil is not effective in all persons. Some persons may have a better hair-growth response than others.
Topical minoxidil is much more effective at treating baldness that occurs on the top, or crown, of the head than it is at causing hair growth on other parts of the head. Minoxidil does not work for everyone and there is no predictor, in early 2001, of whether or not it will be effective in any particular person. Clinical tests on the effectiveness of topical minoxidil in men with baldness on the top of the head showed that 48% of men who had used minoxidil for one year reported moderate to dense re-growth of hair within the treated area. Thirty-six percent reported minimal re-growth. While 16% reported no re-growth. Similar percentages have been reported in women.
In both men and women, hair re-growth generally does not begin until the medicine has been used for at least four months. The first signs that minoxidil may be effective in a particular person usually occur after approximately 90 days of treatment, when the patient notices that he or she is losing (shedding) much less hair than prior to beginning treatment. When new growth begins, the first hairs may be soft and barely visible. For some patients, this is the extent to the effectiveness of this medication. For others, this down-like hair develops into hair of the same color and thickness as the other hairs on their heads.
Minoxidil is a treatment for hair loss, it is not a cure. Once a patient stops taking minoxidil, he or she will most likely lose all of the re-grown hair within 90 days of stopping the medication and no further hair growth will occur.
Side effects of topical minoxidil are few and generally minor (transient skin irritation or itching). The vasodilating (blood-pressure lowering) effect of oral minoxidil does not occur with the topical formulation. There is a small risk for facial hair growth associated with use of minoxidil—a finding that may be a side effect of the drug or may be due to accidental application of the topical solution to the face.
People who have had a prior unusual or allergic reaction to either minoxidil or propylene glycol, a non-active chemical in the Rogaine solution, should not use topical minoxidil. People who have had a previous allergic reaction to preservatives or dyes may also be at risk for having an allergic reaction to minoxidil.
People who are using cortisone, or cortisone-like drugs (corticosteroids), petroleum jelly (Vaseline), or tretinoin (Retin-A) on their scalps should consult their doctors prior to using minoxidil. The use of any of these products in conjunction with minoxidil may cause excessive minoxidil absorption into the body and increase the risk of side effects. Also, people who have skin problems or irritations of the scalp, including sunburn, may absorb too much minoxidil and increase their risk of side effects. As for oral minoxidil, the form prescribed for high blood pressure, patients should use minoxidil only under medical supervision to ensure that excessive amounts of the drug are not absorbed into their bodies. Large amounts of minoxidil may increase the severity of the symptoms and side effects of hypertension. Minoxidil may pass from mother to child through breast milk. Therefore, women who are breastfeeding should not use minoxidil.