It is often clinically desirable to prevent postpartum engorgement of the breast and to induce rapid involution of the lactating breast. Claims have been made and evidence presented that intramuscular camphor in oil causes these effects.1
One of us has had the opportunity to test the effects of this substance. It was given in the approved manner and dosages (3 grains [0.2 Gm.] intramuscularly once or twice a day for five days) to a few postpartum patients. When the results were compared with those obtained in alternate cases in which no treatment had been given, the value of the camphor was not discernible.
With one exception2 in the clinical experiments on this subject, no untreated controls were used. Data were not presented as to the qualitative or quantitative engorgement or the amount of lactation in the untreated control female. It is known that some women do not manifest
Greene RR, Ivy AC. THE EFFECT OF CAMPHOR IN OIL ON LACTATION. JAMA. 1938;110(9):641-642. doi:10.1001/jama.1938.62790090001008