Researchers at the St. Louis University of Medicine collected data from 373 women who anonymously shared info on their sex lives, out of which 176 admitted partaking regularly of cannabis, per a summary of the study from SF Gate's Smell the Truth cannabis news blog. “Among those who reported using marijuana before sex, 68.5 percent stated that the overall sexual experience was more pleasurable, 60.6 percent noted an increase in sex drive, and 52.8 percent reported an increase in satisfying orgasms,” the study’s authors wrote.
The researchers aren't sure why this is the case, leading me to believe these are not researchers who use cannabis themselves. “The question of how marijuana leads to these positive changes in sexual function is unknown,” the authors wondered. “It may lower sexual inhibitions and increase confidence and a willingness to experiment. Marijuana is also known to heighten sensations such as touch, smell, sight, taste, and hearing.” They concluded, "Marijuana appears to improve satisfaction with orgasm.”
The study's authors point out that any conclusion at this point is simply theoretical, and the endocannabinoid system in women requires greater study, although there is potential that more research could lead to new treatments for female sexual dysfunction.