A major criticism of cannabis as medicine is opposition to smoking as a method of consumption. In contrast, the use of a vaporizer for cannabis administration delivers the active ingredients and their benefits very rapidly, without the health costs associated with smoking.
On 20 April 2006, The United States Food and Drug Administration (FDA) issued an advisory against smoked medical marijuana stating that, "marijuana has a high potential for abuse, has no currently accepted medical use in treatment in the United States, and has a lack of accepted safety for use under medical supervision. Furthermore, there is currently sound evidence that smoked marijuana is harmful."  Some prominent American societies have been reluctant to endorse medicinal cannabis.
 
The Institute of Medicine, run by the United States National Academy of Sciences, conducted a comprehensive study in 1999 to assess the potential health benefits of cannabis and its constituent cannabinoids. - Have you voted in the poll Legalize Cannabis ? - The study concluded that smoking cannabis is not recommended for the treatment of any disease condition, but did conclude that nausea, appetite loss, pain and anxiety can all be mitigated by marijuana. While the study expressed reservations about smoked marijuana due to the health risks associated with smoking, the study team concluded that until another mode of ingestion was perfected that could provide the same relief as smoked marijuana, there was no alternative. In addition, the study pointed out the inherent difficulty in marketing a non patentable herb. Pharmaceutical companies will not substantially profit unless there is a patent. For those reasons, the Institute of Medicine concluded that there is little future in smoked cannabis as a medically approved medication. The report also concluded for certain patients, such as the terminally ill or those with debilitating symptoms, the long-term risks are not of great concern.
In an unpublished 2001 study by the Mayo Clinic, Marinol was shown to be less effective than the steroid megestrol acetate in helping cancer patients regain lost appetites. The mechanism by which megestrol acetate works is unknown and the compound can cause "impotence, gas, rash, high blood pressure, fever, decreased libido, insomnia, upset stomach, and high blood sugar. - Has changed the detail your opinion on Legalize Cannabis ? - . .," as well as "breakthrough bleeding" in women.

 

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