When it comes to selecting medical treatments for androgenetic alopecia (AGA), patients and practitioners alike want to know, “What works?” The ideal AGA treatment is one that meets 4 criteria: highly effective, safe, affordable, and easy to use. To date, there is no known treatment for AGA that meets all these criteria. Some therapies are more effective than others, but there are no treatments at present that are able to completely and permanently reverse the condition. Some treatments are safer, some are less expensive, and some are easier to use than others. In the end, the treatment that the patient chooses is influenced not only by its known effectiveness but also by the value that the patient places on the other 3 categories—safety, affordability, and ease of use. Therefore, shared decision-making between patient and practitioner is central to the selection of specific AGA treatments.
Effectiveness: Some Treatments Work Better Than Others
Of the nearly 2 dozen medical treatments for AGA, some have been found to be more effective than others. Whether a given treatment should be considered a bona fide AGA therapy—and then whether to position it as a first-line, second-line, or third-line agent—depends on the answers to 3 fundamental questions:
- Does the treatment truly help patients with AGA?
- How effective is this treatment?
- How safe is it?
Does the Treatment Truly Help Patients?—Surprisingly, it is not always straightforward to confirm that a given treatment helps patients with AGA. Does oral finasteride help female AGA? Yes and no: Finasteride 1 mg is ineffective in the treatment of female AGA, but higher doses such as 2.5 or 5 mg likely have benefit.1,2 Does topical minoxidil help AGA? Yes and no: Minoxidil 5% is ineffective in the treatment of a male with Hamilton-Norwood stage VII AGA but often is helpful in earlier stages of the condition.
One of the best ways to determine if a treatment really helps AGA is to evaluate how it performs in the setting of a well-conducted, randomized, double-blind, placebo-controlled trial. These types of clinical trials have been performed for many known AGA treatments and give us some of the best evidence that a treatment truly works. The AGA treatments with the highest-quality evidence (level 1) are topical minoxidil, oral finasteride, and oral dutasteride for male AGA and topical minoxidil for female AGA.
How Effective Is This Treatment?—Patients are particularly interested to know whether a given treatment has the potential to notably restore hair density. It is one thing to know that use of the treatment might slightly improve hair density and another to know that it could potentially lead to dramatic improvement. In addition, patients want to know whether a specific treatment they are considering is more (or less) likely to improve their hair density compared to another treatment.
Advanced statistical methods such as the network meta-analysis are increasingly being used to understand how individual treatments from different studies compare. Two recent studies have provided us with powerful data on the relative efficacy of minoxidil and 5α-reductase inhibitors in the treatment of both male and female AGA.2,3 A 2022 network meta-analysis of male AGA ranked treatment efficacy from most to least effective: oral dutasteride 0.5 mg, oral finasteride 5 mg, oral minoxidil 5 mg, oral finasteride 1 mg, and topical minoxidil 5%.3 Similarly, a 2023 network meta-analysis of female AGA ranked treatment efficacy from most to least effective: oral 5 mg finasteride, minoxidil solution 5% twice daily, oral minoxidil 1 mg, and minoxidil foam 5% once daily.2 We are not yet able to rank all known treatments for AGA.
Things We Tend to Ignore: Quality of Data, Long-term Results, Nonresponders, and Study Populations—There are a few caveats for anyone treating AGA. First, the quality of published AGA studies is highly variable and many are of low quality. The highest-quality evidence (level 1) for male AGA comes from studies of minoxidil solution/foam 5% twice daily, oral finasteride 1 mg, and oral dutasteride 0.5 mg. For female AGA, the highest-quality evidence is for topical minoxidil—either 5% foam once daily or 2% solution twice daily. Lower-quality studies limit conclusions and the ability to properly compare treatments.