Effects of palmitoylethanolamide formulation on the time course of carrageenan-induced thermal hyperalgesia following intraplantar injection of carrageenan in the rat hind paw. All palmitoylethanolamide (PEA) formulations (10 mg/kg for each) were administered orally or intraperitoneally 30 minutes before carrageenan (CAR) injection. Hyperalgesia was assessed at the time points indicated. (a) Micronized PEA-m and ultramicronized PEA-um produced significant improvements in both scores in comparison to PeaPure. (b) Intraperitoneal administration did not show a significant difference between treatment groups. See Methods for further details. Values are means ± SEM. *P < 0.05 and **P < 0.01 vs CAR.