Marijuana (Cannabinoids)Pregnancy

Negative effects of cannabinoids on human sperm

Delta(9)- and Delta(8)-tetrahydrocannabinol (THC) are potent inhibitors of mitochondrial respiration in human sperm, according to this study by researchers at the State University of New York, Upstate Medical University in Syracuse.

First, the details.

  • 41 men being evaluated for their fertility were studied.
  • A phosphorescence analyzer was used to measure the oxygen concentration in sperm suspensions over time as a reflection of spem respiration.

And, the results.

  • There was an immediate decline in the rate of respiration in sperm in the presence of Delta(9)-THC or Delta(8)-THC.
  • This effect was concentration dependent, with Delta(9)-THC the more potent of the two compounds.
  • Respiration was much less affected when Delta(9)-THC or Delta(8)-THC was added to semen that was not exposed to pot, suggesting the presence of protective factors in seminal plasma.
  • Both compounds inhibited the respiration of isolated mitochondria, illustrating that direct mitochondrial damage is likely the primary mechanism of action.

The bottom line?
The 2 main active cannabinoids of the marijuana plant, Delta(9)- and Delta(8)-THC, are potent inhibitors of mitochondrial oxygen consumption in human sperm.

The authors concluded, “These findings emphasize the adverse effects of these toxins on male fertility.”

6/24/08 21:32 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.