Apart from rest in bed, various pharmacotherapeutic approaches are recommended in the treatment of chronically deficient foetal supply. Xantinol nicotinate (Complamin retard) was examined with regard to its influence on the human placental lactogen (HPL) values in a preliminary study followed by a double-blind study. In the first experimental series, 53 pregnant women were treated on an in-patient basis because of suspected placental insufficiency. In 22 women treatment was effected by ordering complete rest in bed, whereas 31 women received for at least three weeks Complamin retard in addition to the "rest in bed" treatment. Rise in HPL levels was significantly more frequent with the Complamin group than with the group of women who had rested in bed only without receiving any pharmacotherapy. A double-blind study was conducted also in patients suspected of placental insufficiency. 25 pregnant women received Complamin retard for three weeks in succession, whereas 25 other pregnant women were given placebo tablets only. Here, too, it was statistically evident that the HPL values increased more often with the Complamin than with the placebo group of patients.