Applying the "Gold Standard"

Women, like men, are subject to the inherited pattern hair loss known as androgenetic alopecia (AGA). Male and female pattern hair loss have different appearances, but the underlying, inherited cause is the same. Female pattern hair loss may begin as early as the teen-age years. About 50% of women over age 40 have some degree of female pattern hair loss. (Click Female hair loss for more information about AGA in women).

A woman’s first indication of female pattern hair loss may be excess shedding of hair noted in combing and brushing. As hair loss continues over time there will be patchy areas where bald scalp is visible. Women rarely become frankly bald like men with male pattern hair loss, but the typically diffuse, patchy hair loss associated with female pattern AGA is cosmetically unappealing and gives a woman an appearance of being older than her calendar years.

What does a woman do when she discovers she is losing hair? Most likely she will look for a remedy to stop hair loss and restore hair growth.

She will not have far to look. Women are bombarded with newspaper, magazine and World Wide Web advertisements for hair loss treatments -secret formulas, vitamin and mineral-containing creams and ointments, and herbal remedies. Many make promises for hair restoration that seem too good to be true. Most of the promises are not, in fact, based upon any credible evidence.

The fastest and surest way to effective treatment of female pattern hair loss is to consult a physician hair restoration specialist. Effective treatment begins with diagnosis of the cause of hair loss, assessment of the progression of hair loss, and a plan of treatment based upon diagnosis and assessment. Click to Find a hair restoration doctor in your area. How should a woman sort through all of the claims and hype associated with hair restoration remedies?

She should ask: Which product claims are based on the "gold standard" of randomized, double-blind, placebo-controlled, multicenter clinical trials involving a statistically meaningful number of patients entered into a statistically well-designed study?

What Constitutes a "Gold Standard" Study

  • Patients selected for the study are randomly assigned to receive the drug being tested or a non-drug placebo. Physician investigators have no control over the randomization process. Patients selected for the study have the physical and physiologic characteristics necessary for the study -for example, they have female pattern hair loss within designated degrees of severity.
  • A study protocol is written to assure that (1) patients selected for the study have the characteristics necessary to test the drug versus placebo, (2) the study will be conducted for a period of time necessary to obtain valid results, (3) the number of patients in the study is statistically meaningful, and (4) the study design is statistically sound.
  • Neither patients nor investigators can know which patients receive the drug and which the placebo until the study is completed - the study is double blind.
  • The effects of the test drug are compared to the effects of placebo in patients who received the drug versus those who received the placebo - the study is placebo-controlled.
  • The study is simultaneously conducted at several medical research centers by investigators at each site who follow the study protocol.

Using the "gold standard" criteria, very few of the claims for "miracle", "secret formula", "vitamin and mineral" and "herbal" hair restoration remedies are found to be based on valid evidence. No product that lacks such evidence has been approved by the U.S. Food and Drug Administration (FDA) for use in treating female pattern hair loss.

The only agent subjected to "gold standard" clinical trials and approved by the FDA for treatment of female pattern hair loss is topically-applied minoxidil (Rogaine®). Topical 2% minoxidil has been shown to stimulate new hair growth and stop hair loss in both men and women with AGA pattern hair loss. Minoxidil 2% solution is approved by the FDA for treatment of AGA in both men and women. Higher concentration 5% minoxidil solution has been shown in clinical trials to enhance therapeutic efficacy without any increased safety risk. Minoxidil 5% solution is approved by the FDA for use in men. Clinical trials have shown that 5% minoxidil solution also improved results in women.

Applying the "Gold Standard" to 2% and 5% Minoxidil in Treatment of Female Pattern Hair Loss: A Newly Reported Study

In a multicenter study of 2% and 5% minoxidil in treatment of female pattern hair loss reported in the April 2004 issue of the Journal of the American Academy of Dermatology (Vol. 50:541-553), the investigators who conducted the study called attention to the increasing importance of the "gold standard" in assessing hair restoration agents:

"With the introduction of numerous herbal remedies for hair loss, of which most have not been tested in randomized, double-blind, placebo-controlled trials, it is important to describe well-controlled trials that demonstrate the efficacy and safety of topical drugs"

The Study

A randomized, double-blind, placebo-controlled trial of 5% and 2% topical minoxidil solutions in the treatment of female pattern hair loss was conducted at nine research sites for a 48-month period in 1992-93.

Women in the Study

Women accepted into the study were 18 to 49 years old with naturally dark hair. Average age was 37 years; 74% of the women were of Caucasian ancestry. All had female pattern hair loss characterized as gradual and conspicuous, with diffuse (patchy) thinning from front to back over the mid-scalp area. Some patients also had thinning of the frontal hairline. The degree of hair loss was rated according to the widely accepted Savin Female Density Scale; a density rating of 4 to 7 was required for acceptance into the study. On the basis of the Savin Density Score, the mean density score was 4.8, 4.7 and 4.7 in the 5%, 2% and placebo groups respectively. Hair counts were made with computer-assisted scans of photographs of clipped hair in a 1 square centimeter target evaluation site within an area of thinning. Evaluation of hair counts was made by a technician who was "blinded" regarding the name of the patient, treatment group, and whether the photos were made at 8, 16, 32 or 48 week time-points. Hair counts per square centimeter were used to evaluate mean change in hair count from baseline. Patients were not accepted if other reasons for hair loss were present, such as systemic disease, scalp disease, current or recent pregnancy, and use of certain drugs. A total of 381 women were entered into the 48-week study, 260 women completed the study.

Study Design

Of the 381 patients who entered the study:

  • 153 received 5% minoxidil solution
  • 154 received 2% minoxidil solution
  • 74 received placebo (the propylene glycol and ethanol vehicle for the 5% solution)

Patients applied 1 milliliter of their assigned solution twice daily at 12-hour intervals for 48 weeks.

Efficacy Evaluation

The therapeutic efficacy of 5% and 2% minoxidil solution was assessed at intervals and at the end of the 48-week study on the basis of:

  1. change in hair count from the baseline count made at the beginning of the study
  2. the patients’ own assessments of hair growth and scalp coverage from baseline to end of study
  3. investigator assessment of hair growth and scalp coverage from baseline to end of study.

Safety Evaluation

Safety monitoring was conducted over the 48-week period of the study to detect any systemic or local side effects or adverse reactions.

Statistical Analysis

The study was developed and monitored to assure statistical accuracy, statistical power, and absence of bias.

Results of the Study

At the end of the 48-week study, 260 patients were available for evaluation. Of the 381 patients who entered the study, 121 withdrew:

  • 40 for non-serious drug-related adverse events such as itching and scaling
  • 25 at the request of the patients (moved away, could not make appointments, etc.)
  • 26 lost to follow-up for unknown reasons.

Hair Count

At 48 weeks, the mean change from baseline hair counts showed that 5% and 2% minoxidil solution had results significantly superior to placebo. The superior results began at Week 8 and continued to the end of the study. Results were slightly better for 5% minoxidil solution, but the superiority of 5% over 2% solution was less than the superiority of both over placebo. Mean change from baseline at Week 48 in 1-square-centimeter hair counts were 24.5 in the 5% minoxidil group, 20.7 in the 2% minoxidil group, and 9.4 in the placebo group.

Patient Evaluation

At Week 48, patients in the 5% minoxidil group rated results that were (1) significantly superior to results in the placebo group, but (2) not to results in the 2% minoxidil group. Patient evaluation scores in both the 2% and 5% minoxidil groups were higher than patient evaluation scores in the placebo group. The 5% minoxidil group rated results higher than the 2% group for the evaluation categories of hair growth, global benefit, hair styling and quality of life.

Investigator Evaluation

Investigators rated scalp coverage in the 2% and 5% minoxidil group significantly superior to scalp coverage in the placebo group at 48 weeks. No statistically significant difference was found between the 5% and 2% minoxidil groups in evaluation of scalp coverage.

Safety Evaluation

Drug-related adverse events were more common in the 5% minoxidil group (14%) than in the 2% minoxidil group (6%) and the placebo group (4%). The most common drug-related adverse events were pruritis (itching), scalp dermatitis, scalp skin scaling, and hypertrichosis (excessive facial hair growth). Four patients had excessive facial hair growth and three of those dropped out of the study. One unexplained adverse event was excessive hair shedding at Week 48 in two patients in the 5% minoxidil group at the same research site.

Conclusions of the Investigators

The investigators found that topical 5% minoxidil solution was statistically superior to placebo in promoting hair growth in women with female pattern hair loss, for all three efficacy measures assessed by the study (change from baseline hair density, patient evaluation, investigator evaluation of scalp coverage). Topical 2% minoxidil solution was superior to placebo in two of the three efficacy measures assessed (change from baseline hair density, investigator evaluation of scalp coverage). The study showed that not all women benefit from minoxidil treatment and that benefit will vary from individual to individual. Some women are unable to tolerate minoxidil treatment due to drug-related side effects and adverse reactions. These efficacy and safety assessments stress the importance of "gold standard" evaluation of hair restoration remedies.

Results of the study indicate that minoxidil is likely to be most effective when used in a planned program of hair restoration under the supervision of a physician hair restoration specialist. A physician hair restoration specialist will plan a program of hair restoration based upon diagnosis of the cause of hair loss, severity and progression of hair loss, individual patient characteristics, and the patient’s wishes for treatment outcome. Some women who are using and benefiting from topical minoxidil solution may receive further benefit from hair transplantation. The best way to determine if one is a candidate for hair transplantation is to have an evaluation by a physician hair restoration specialist.

Share this article:

Twitter icon
Facebook icon
LinkedIn icon