320px-Cannabis_PlantWe have written repeatedly how “medical” marijuana is difficult to dose accurately. Because marijuana’s potency varies from plant to plant–depending on a host of factors, including growing conditions–there is no guarantee two samples of marijuana will contain identical levels of active ingredients.

This is simply one reason we feel “medical” marijuana is really a misnomer.

Earlier this year the Journal of the American Medical Association published a study analyzing “dose accuracy of labels from edible medical cannabis products dispensed in 3 U.S. cities.”

Researchers analyzed 75 food products infused with marijuana, checking the levels of THC and cannabidiol in each item.

Of the marijuana edibles they tested, only 17% were accurately labeled. 23% were under-labeled, meaning there was more drug content in the edible than indicated on the label; 60% were over-labeled, meaning there was less marijuana in the product than indicated on the label.

The fact that edible marijuana often is not properly labeled is significant. Many cases of marijuana poisoning and marijuana overdose cited in the news have been the result of people eating marijuana-infused food without realizing just how much marijuana the food contained. If marijuana products are not properly labeled, how can people possibly know how much of the drug they are ingesting?

Of course, inaccurate labeling would not be a problem if marijuana were as harmless as many of its supporters claim, but it isn’t. Researchers increasingly link marijuana use to a variety of negative side-effects ranging from paranoia and reduction in IQ to even stroke, heart attack, and latent schizophrenia.

Uniformity in dosing is a hallmark of modern medicine. Imagine opening a bottle of Tylenol only to find some tablets contained more acetaminophen than others. It would be unthinkable, and yet that’s what we seem to find with “medical” marijuana.

As we keep saying, inconsistency in dosing is just one more reason “medical” marijuana is a misnomer.

You can read the JAMA article here.

Photo Credit: “Cannabis Plant” by Cannabis Training University – Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons.