If you're a medical marijuana consumer who favors edible forms of the drug over smoking it, how do you know the product you're getting is as potent as the label claims?

The Oregonian/OregonLive recently examined the market for marijuana-infused edibles, a fast-growing segment of the medical cannabis industry, and found wide discrepancies between what's on the label and what's in the product.

The state assures consumers that medical cannabis and cannabis-infused products undergo a battery of lab tests for everything from pesticides to potency before landing on dispensary shelves.

Yet when it comes to potency that promise is largely an empty one, a three-month investigation by The Oregonian/OregonLive has found.

Medical marijuana testing in Oregon is done by a cottage industry with an estimated 19 labs operating without oversight or clear scientific standards. While Colorado's testing industry is subject to tight regulation involving audits and on-site inspections, Oregon public health officials don't actually know how many marijuana-testing labs operate in the state.

The Oregonian/OregonLive commissioned a respected analytical chemist to conduct a detailed potency analysis of 15 marijuana-infused edible products sold in Portland dispensaries and found only one contained accurate potency information on its label.

The analysis was performed by Rodger Voelker, scientific director at OG Analytical, a marijuana-testing company in Eugene. He tested marijuana-infused products ranging from ice cream to kombucha.

The results were all over the place.

-- Noelle Crombie