PIP: Plasma prolactin levels and milk volume were studied in 50 maternity patients for 8 days after delivery. 1 group of patients received no medication, while other groups received methergine (.2 mg 3 times daily), syntocinon (200 u 3 times daily), Vitamin-B6 (300 mg twice daily), or quinestrol (4 mg, single dose), respectively. None of these influenced prolactin secretion substantially although prolactin levels were slightly higher in the quinestrol-treated group. There was no evidence of an antilactation effect of Vitamin-B6, while the lactation-inhibiting effect of Quinestrol must be ascribed to a periperal effect.