Last week the cover story of Seven Days addressed whether Vermont ought to follow up last year's medical marijuana legislation with further decriminalization of pot possession. Both notions are still considered radical by legislators in many states -- only about a dozen have approved the use of medical marijuana for patients with terminal or chronic illnesses. Meanwhile, on April 19, the Canadian government delivered a body blow to the U.S. government's opposition to medical marijuana. It approved prescription sale of a natural marijuana extract to treat pain and other symptoms caused by multiple sclerosis.

Sativex, produced by GW Pharmaceuticals in Britain, brings the medical marijuana debate full circle. Though the technology has advanced in 70 years, this product is a direct descendent of the marijuana extracts and tinctures that were a standard part of the medical armamentarium until the late 1930s -- universally recognized as being safe and effective for certain conditions. These products were taken away from patients and doctors as a result of the prohibition on marijuana that began in 1937, despite the public opposition of the American Medical Association.

In short, the Canadian government has just certified that virtually everything our own government has been telling us about marijuana is wrong. In defiance of a large and growing pile of scientific studies, this administration still claims that marijuana has no medical value. White House Drug Czar John Walters has even compared medical marijuana to "medicinal crack."

Make no mistake: Sativex is liquid marijuana. It is nothing like Marinol, the synthetic THC pill sold in the U.S. and sometimes falsely touted as an adequate substitute for marijuana. Sativex is a whole-plant extract, containing the rich variety of naturally occurring compounds called cannabinoids that are unique to marijuana. It also contains trace elements of other compounds contained in the plant, which scientists believe contribute to its therapeutic value.

On its website GW Pharmaceuticals explains, "We believe very strongly that many of the advantages of using the whole plant come from the inclusion of other components of cannabis [marijuana]," not just THC. "In the cannabis plant, it appears that some of the components added together give better effect. Some components seem to work to counteract some of the side effects of others, and the whole plant is generally well tolerated by humans."

Studies have shown significant effect against pain and other symptoms caused by multiple sclerosis and other debilitating conditions. Over 600 patient-years of research have established a remarkable record of safety. Sativex is to marijuana as a cup of coffee is to coffee beans. If Sativex is safe and effective, marijuana is safe and effective.

Rob Kampia is executive director of the Marijuana Policy Project in Washington, D.C.