Tonic analgesic effects of delta 9-tetrahydrocannabinol as measured with the formalin test

Eur J Pharmacol. 1980 Feb 8;61(3):313-5. doi: 10.1016/0014-2999(80)90134-x.


The analgesic effects of delta 9-tetrahydrocannabinol (THC), the psychoactive component of marihuana, were tested using the formalin test. Rats were treated with either THC (5 mg/kg or 10 mg/kg) or a placebo by gavage 4 h before the formalin test for analgesia was initiated. THC produced a highly significant analgesic effect against both phasic pain and tonic pain. THC is discussed as a model for the development of new analgesics or as a suitable analgesic if used with another potentiating drug.

MeSH terms

  • Analgesics*
  • Animals
  • Body Temperature / drug effects
  • Dronabinol / pharmacology*
  • Female
  • Formaldehyde / pharmacology*
  • Male
  • Pain / chemically induced*
  • Pain / physiopathology
  • Rats
  • Time Factors


  • Analgesics
  • Formaldehyde
  • Dronabinol