Maturing Masculinities is a nuanced exploration of how older men in urban Mexico incorporate aging, chronic illness, changing social relationships, and decreasing erectile function into their conceptions of themselves as men. It is based on interviews that Emily A. Wentzell conducted with more than 250 male patients in the urology clinic of a government-run hospital in Cuernavaca. Drawing on science studies, medical anthropology, and gender theory, Wentzell suggests the idea of "composite masculinities" as a paradigm for understanding how men incorporate physical and social change into gendered selfhoods. Erectile dysfunction treatments like Viagra are popular in Mexico, where stereotypes of men as sex-obsessed "machos" persist. However, most of the men Wentzell interviewed saw erectile difficulty as a chance to demonstrate difference from this stereotype. Rather than using drugs to continue youthful sex lives, many collaborated with wives and physicians to frame erectile difficulty as a prompt to embody age-appropriate, mature masculinities.