The measurement of oxytocin concentration is saliva is a common approach for the approximation of peripherally circulating oxytocin, however, the validity of this approach is poorly understood. This study compares saliva and blood plasma oxytocin after both intranasal and intravenous oxytocin administration, with the results suggesting that saliva oxytocin concentrations do not accurately index peripheral oxytocin after intranasal or intravenous oxytocin administration.