Using the latest research to support their claims, advocates for the medical use of marijuana are heading to court.
A new study which provides evidence that marijuana eases pain in some HIV cases, is being used in another attempt to decriminalize the drug by suing the federal government.
The lawsuit has been filed in the federal court by the nonprofit organization Americans for Safe Access and it claims that the U.S. Department of Health and Human Services is engaging in "arbitrary and unlawful behaviour" which prevents "sick and dying persons from seeking to obtain medicine that could provide them needed, and often lifesaving relief".
The advocacy group wants to use the law to force the department and the Food and Drug Administration (FDA) to stop releasing information that casts doubt on the efficacy of marijuana in treating various illnesses.
The lawsuit differs from previous legal efforts to decriminalize marijuana because it seeks to get a federal agency simply to acknowledge that marijuana can help reduce the symptoms of some conditions.
This latest attempt to clarify the use of marijuana for medical reasons aims to force the government to stop classifying marijuana as an illegal drug.
Joe Elford, chief counsel for Americans for Safe Access, says they are not asking the federal government to change what it does about medical marijuana, but what they say about it.
He believes this would make it easier for states to develop their own medical marijuana policies.
Advocates say along with discouraging people who might benefit from smoking pot, the FDA's current position only serves to encourage the Drug Enforcement Agency's to penalise against the use of medical marijuana in states where the practice is in fact legal.
Despite the fact that California is one of 11 states where marijuana use is legal for people with a doctor's recommendation, the DEA considers marijuana illegal, which means patients can still be arrested and prosecuted by federal authorities.
The new research from the Clinical Research Center at the University of California, San Francisco has established that HIV patients who smoked pot, experienced far less pain than those given placebos.
Americans for Safe Access say that a Health and Human Services statement which rejects that medical use of marijuana in treatment in the United States, a position the agency has held since 2001, is not based on evidence.
The group say the FDA have publicly issued "false and misleading statements" about the medical benefits of marijuana.
Since California voters approved medical marijuana use in 1996, 10 other states have adopted measures protecting qualified patients from state prosecution. They are Alaska, Colorado, Hawaii, Maine, Montana, Nevada, Oregon, Rhode Island, Vermont and Washington.
The research is reported in the journal Neurology.