For some men, it begins working in as early as 12 minutes and for most within 30 minutes. It only works when you are sexually stimulated but you may take it up to four hours before sexual activity. Orgasm and ejaculation occur as normal and after sex your erection should go away1. For most men, Viagra® works on the first or second attempt.
References: 1. Viagra NZ Data Sheet. Available at www.medsafe.govt.nz. Accessed Sept 2026