Last fall, fur flew as drug-war types fought to block the legalization of medical marijuana in California and Arizona. Buyers clubs around the country were padlocked, and advocates arrested. Even drug czar Gen. Barry McCaffrey weighed in, saying, “There is not a shred of evidence that shows smoked marijuana is useful.” But voters passed the medical-marijuana measures anyway.

Caught in the crossfire, Dr. Donald Abrams, of the University of California San Francisco School of Medicine, was denied federal approval to conduct a study on the herb’s medicinal effects-despite the fact that experts day such research is needed to resolve the issue. “Critics say there’s no scientific evidence that marijuana has any benefit,” Abrams said. “In the meantime, we’re not allowed to do a study.” Numerous studies have shown that pot relieves nausea and pain, improves appetite and, in glaucoma sufferers, reduces eye pressure.

Abrams had initially designed an outpatient study to compare the use of the standard treatment, Marinol, or dronabinal-which contains pot’s active ingredient-with smoked marijuana for treating AIDS-related weight loss. Both the Research Advisory Panel of California and the Food and Drug Administration gave him the go-ahead way back in 1994, but the Drug Enforcement Administration, which issues licenses to prescribe marijuana, turned him down. The National Institute on Drug Abuse, which frowns on any study that might show pot to be beneficial, refused to provide Abrams with 5.7 kilograms of pot, claiming the study was unscientific.

So Abrams redesigned the study to test the effects of marijuana on hospital patients against a placebo. Surprise! Reviewers at the NIH told him marijuana was too toxic for people with AIDS-related wasting; they also worried that pot-smoking sick people who got the “munchies” might increase their cholesterol levels, leading to hardening of the arteries over time. “Our patients really don’t have that luxury,” Abrams said. The indefatigable researcher is now designing a safety study to look at the toxicity of marijuana.