Androgenetic alopecia (AGA) is the most common cause of hair loss in both men and women, affecting nearly 50% of Caucasian men > 50 years old and 50% of Caucasian women > 60 years old, with a slightly lower prevalence in individuals of Black and Asian ethnicities.1,2 Despite the high prevalence of AGA, there are only 2 treatments approved by international regulatory bodies: topical minoxidil (for male and female AGA) and finasteride, both oral and topical, for male AGA. However, multiple drugs are used off-label.3,4 Additionally, several techniques for AGA treatment have been developed, such as mesotherapy with platelet-rich plasma (PRP) or low-level laser therapy, which have shown variable efficacy in the management of AGA.5–10

Despite the coexistence of multiple therapies for AGA widely used in the routine clinical practice, most of them have not undergone clinical trials to confirm their efficacy and safety profile in AGA treatment. Although these treatments are often safe, sometimes of common use in other medical areas, their side effects can be severe,11–13 which stresses the need for research into new AGA therapies.

This consensus document aims to provide guidance to health care professionals on the currently available treatments for the management of AGA in our routine clinical practice.

This consensus document was designed and developed by members of the Spanish Hair Disorders Group (GET) of the Spanish Academy of Dermatology and Venereology (AEDV) using a modified Delphi method following RAND/UCLA recommendations,14 and in full compliance with the principles set forth in the Declaration of Helsinki.

To create the preliminary questionnaire, a scientific committee was created, including 8 participants, all dermatologists with over 5 years of clinical experience in hair disorders, and members of the GET-AEDV. A qualitative literature review was conducted in 4 thematic blocks (generalities, medical treatment of AGA, procedures and hair transplantation, and special cases). This literature review was conducted in October 2022, was limited to articles published in English and/or Spanish since 2012 indexed in the following databases: Medline (via PubMed), Embase, The Cochrane Library, MedEs, Epistemonikos, Joanna Briggs Institute Evidence Based Practice Database, and Tripdatabase.

After the literature review, a questionnaire of 160 statements was created and sent to the panelists to be answered online. A group of 34 Spanish dermatologists, all members of the GET-AEDV, participated as panelists and voted in both rounds.

A total of 2 rounds of voting were conducted. Panelists scored each statement using a Likert-type ordinal scale of 9 points (1, strongly disagree; 9, strongly agree). Responses were categorized into 3 groups: 1-3 (disagree), 4-6 (neutral), and 7-9 (agree). For an item to be considered consensually agreed or disagreed upon, it should meet the following criteria: 1) a median of responses within the range of 1-3 or 7-9; 2) less than one-third of the votes outside the range of 1-3, or 7-9, and 3) an interquartile range (IQR) ≤ 3.

After the 1st round of voting, the scientific committee met for an interim analysis, reediting several statements that had not reached consensus. These statements underwent a 2nd round of voting. Panelists were briefed on the responses from the 1st round before casting their votes in the 2nd one.

After completing the 2nd round, the scientific committee drafted the consensus document, assigning a level of evidence (LE) to each recommendation, and a grade of recommendation (GR), following the recommendations issued by the Center for Evidence-Based Medicine at Oxford.15

In the 1st round, a total of 130 items were agreed upon. After the 1st round, a total of 8 recommendations were re-edited, and after the 2nd round, a total of 12 additional recommendations were agreed upon. After the 2 rounds of the Delphi method, 138 out of the proposed 160 items were agreed upon (86%) (see supplementary material, tables A.1-A.4).

This consensus document provides guidelines on the management of AGA and aims to assist in the management of this condition, which is characterized by its high prevalence in our environment.

Regarding the general aspects of AGA management, we should mention that despite the fact that there is a growing number of therapeutic tools currently available, management can be complex due to several factors: the limited number of approved treatments for AGA, the wide variety of off-label treatments available, the lack of clinical trials on different treatments, as well patient preferences and expectations.3,4,16–18 In cases where off-label therapies are necessary, and while considering ethical and legal implications, it is recommended to inform the patient and obtain his/her verbal or written consent, documenting everything in the patient's health record.

This consensus positions oral dutasteride as the first-choice drug for MAGA despite being an off-label indication (Table 1). This is due to dutasteride greater efficacy profile compared to finasteride, with a similar safety profile.19–21 Similarly, low-dose oral minoxidil is recommended as the first choice for both FAGA and MAGA due to its superior efficacy compared to topical minoxidil and few adverse events reported so far.11,22–26 The combination of topical or oral minoxidil with an antiandrogen (5-alpha-reductase inhibitor, or spironolactone) is considered the first-line therapy for FAGA (Table 2) despite finasteride and dutasteride being contraindicated in the product label. Regarding topical minoxidil, despite being one of the only 2 approved treatments for AGA, panelists suggested sparing its use for the early stages of the disease, given the drug's greater efficacy in oral formulation.27

In terms of hormonal treatment, panelists positioned spironolactone as the first-line therapy for FAGA in premenopausal patients;28 second-line options include oral contraceptives and bicalutamide.29–31 Due to the potential risk of meningioma, cyproterone acetate is not recommended in the management of FAGA, except for cases unresponsive to other drugs.32,33 Individualizing the use of nutricosmetic products, including those with natural antiandrogenic activity, is advised due to their low efficacy.34

While most AGA treatments are safe, and serious side effects are rare, there are several drugs whose prescription requires periodic monitoring through lab tests, such as bicalutamide for the potential risk of hepatotoxicity, or spironolactone in patients with a past medical history of kidney disease or electrolyte disorders (Table 3).35

Mesotherapy and other technological interventions are adyuvants to pharmacological therapy for AGA36,37, although their effectiveness has proven low/moderate in some former studies. PRP treatment,9,38–40 and low-energy laser therapy5–7,41 have proven efficacy in the management of MAGA/FAGA but with highly variable results, thus requiring individualized use in each case. An administration scheme for PRP has been agreed upon, recommending an initial regimen of 3 monthly sessions, without plasma activation prior to the administration (Table 6). No consensus was ever reached on the best low-energy laser treatment regimen, as the application protocols for different light systems are not well established, nor their combination with other mesotherapy treatments. However, they should be administered, at least, 3 times a week to assess their effectiveness. Several recommendations regarding procedures such as mesotherapy, microneedling, and treatments with botulinum toxin did not reach consensus due to the lack of scientific evidence to date, which stresses the need for further studies to validate their safety and efficacy profile.

Hair transplantation is becoming increasingly common in the routine clinical practice,42–44 and this document supports its use in selected patients. Before recommending hair transplantation, it is necessary to make sure that alopecia has stabilized, which is ill-advised in young patients. However, it can be considered even as the only treatment in elderly patients with established alopecia.

This document is a useful guide for special and challenging cases for dermatologists, such as the management of pediatric patients, older patients with comorbidities, or pregnant women (Table 7). A multidisciplinary approach, with assessments by pediatric endocrinology, is advised for pediatric/adolescent patients with AGA.45 Similarly, the importance of staying coordinated with primary care physicians and/or specialists is emphasized in the case of elderly patients, or those with significant comorbidities. During pregnancy, we should mention that most pharmacological treatments should be avoided, although specific nutricosmetics designed and approved for pregnancy, low-power laser therapy, and platelet-rich plasma treatment can be considered if clinically necessary.

The management of AGA can be complex due to the wide range of therapies currently available, often with variable evidence regarding their efficacy and safety profile. This consensus document is based on the scientific evidence available to date, and expert opinions to help professionals in the management of AGA in the routine clinical practice.

This article has been funded by the Spanish Hair Disorders Group of the Spanish Academy of Dermatology and Venereology.

Dr. Sergio Vañó-Galván declares being an advisor to Lilly and Pfizer. The remaining authors declared no conflicts of interest whatsoever.