Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Credit: Sildenafil, the active ingredient in Viagra. Annie Cavanagh. Source: Wellcome Collection.
Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Credit: Sildenafil, the active ingredient in Viagra. Annie Cavanagh. Source: Wellcome Collection.