beta-Endorphin: intranasal administration increases the serum prolactin level in monkey.

Human beta-endorphin has been administered by nasal spray technique at a dose of 0.02 mg per kg in female bonnet monkeys. A significant increase of serum prolactin levels was observed within 30 min and maintained up to 60 min. In the same dose, intravenous injections of the hormone caused a marginal increase of prolactin levels only after 60 min. It was concluded that administration of beta-endorphin by nasal spray is more effective than the intravenous injection.