The Use of 2D:4D Digit Ratio as a Predictor of Androgenetic Alopecia: A Review

Androgenetic alopecia (AGA) is a widespread type of hair loss that affects both males and females. Advanced age and family history of AGA are well-established risk factors for developing AGA. The second to fourth digit ratio (2D:4D) is the ratio between the length of the index and ring fingers. This ratio has been utilized as a predictor for multiple hyperandrogenism-related medical conditions. More recently, 2D:4D was investigated as a predictor for AGA. This article aims to investigate the evidence supporting the use of 2D:4D as a predictor of AGA, and address areas of future research.