Abstract
The analgesic effect of paracetamol, acetyl-salicylic acid, and placebo on dysmenorrhea were compared in a double-blind cross-over study of 30 women. There was a moderate placebo effect, but no significant difference was found between the three treatments. Blood loss was also measured and it did not vary, with the type of drug ingested. It is concluded that paracetamol and acetylsalicylic acid in the doses used (0.5 g x 4 for 3 days) were not effective against heavy dysmenorrhea, and that none of the drugs influenced the amount of blood lost.