Now to be very accurate, from the Oxandrin insert.
In a single dose pharmacokinetic study of Oxandrin in elderly subjects, the mean elimination half-life was 13.3 hours. In a previous single dose pharmacokinetic study in younger volunteers, the mean elimination half-life was 10.4 hours. No significant differences between younger and elderly volunteers were found for time to peak, peak plasma concentration or AUC after a single dose of Oxandrin.