I recently visited a medical-marijuana dispensary in Denver. I expected tie-dyed tapestries and Bob Marley posters. Instead, I found a well-designed shop that looked like any high-end health-supplement boutique.

The display cabinets were organized with various strains of marijuana and there were many non-smokable types, including transdermal patches, oral sprays and edibles. An employee proudly explained that in Colorado, dispensaries are required to grow at least 70 percent of their inventory, a boon to small operators. This particular dispensary grew 90 percent of its inventory and sourced the plants out to other small businesses that transformed them into the patches, sprays and edibles.

The business model was impressive. That the medical model was lacking soon became apparent.

When I asked about the difference among the various types of marijuana for sale, I was told that one strain was good for nights when one felt like staying home drawing, another for feeling more social at parties and a third for sitting on the couch watching an Adam Sandler movie. I did not hear about AIDS wasting, nausea, muscle spasms, glaucoma, seizures or the other conditions that marijuana is claimed to alleviate.

The employee knew a lot about marijuana, but no more about medicine than might be expected from someone working at that high-end health-supplement boutique the dispensary so resembled.

Is this acceptable for something that is being called "medical"?

The Minnesota Legislature is considering a bill allowing marijuana to be used for select medical diagnoses. I want to be very clear that I am neither for nor against marijuana. It is addictive; the U.S. National Survey on Drug Use and Health shows that 1 in 12 people who used marijuana last year were addicted to it. This places it between alcohol (1 in 21) and tobacco (1 in 3). Yet these drugs are legal. Marijuana can impair driving and worsen some psychiatric diagnoses, as does alcohol. It does not cause overdose deaths like we have seen with opioid pain relievers. If marijuana becomes available in Minnesota, I am confident that just as for alcohol, tobacco and pain relievers, we can implement effective prevention and treatment strategies to minimize its harm.

I oppose the current bill not because it is marijuana but because it is being called medical. The medical profession relies on standards of evidence to guide its practice. Multiple organizations including the august Institute of Medicine agree that some components of marijuana likely will have medical benefit. They also agree that the evidence is not yet there and that rather than widespread implementation, we need more research.

Furthermore, while most medications have a botanical origin, their transformation into medicine requires high standards of purity and consistency in production. Aspirin has its origin in willow bark, but every aspirin tablet in every bottle is comparable not just in terms of the aspirin itself but also the inactive ingredients; every step in the manufacturing process has been rigorously studied for safety and purity. A doctor will recommend aspirin for specific medical conditions but is not likely to recommend drinking willow bark tea.

The quality control we expect from medicine has not been written into Minnesota's medical marijuana bill. What soil, what fertilizers, what pesticides, what nutrients are to be used by marijuana growers? Can we be assured that every dose of marijuana no matter where produced or sold will be the same as every other? If it is medical, should there be knowledge standards for employees who work in dispensaries much as we expect for pharmacists, so a person seeking help can learn more than what strain will improve an Adam Sandler movie?

The Minnesota bill does not answer any of these questions. Under the bill, patients must receive a written certification from a licensed health practitioner stating that they have a legislatively defined medical condition that likely will benefit from the use of marijuana. Restricting marijuana to predefined conditions based on preliminary evidence is not such a bad idea, but how can a health practitioner realistically opine on the matter when appropriate safety and production standards do not exist?

As the bill currently reads, medical marijuana in Minnesota is more consistent with the standards we have for high-end health-supplement boutiques. Perhaps if Minnesota wants marijuana under the claim of health, then the Legislature should absolve physicians from the responsibility of certifying its use. Perhaps it should be treated much as the impression my experience in Denver left me: that marijuana is not ready for medicine, but it may be better suited to the unsubstantiated claims and unexacting production standards we are happy to accept from a health-supplement boutique. Let GNC or the Vitamin Shoppe take on the mantle of "health" marijuana and leave medicine out of it.

Gavin Bart is director of addiction medicine at Hennepin County Medical Center and an associate professor of medicine at the University of Minnesota.