The U.S. House of Representatives has passed yet another cannabis research bill. The Medical Marijuana and Cannabidiol Research Expansion Act aims to encourage research into the positive medical benefits of the drug. But something is missing.

“Research is a foundational element for cannabis policy,” said Rep. Earl Blumenauer (D-Ore.), founder and co-chair of the Congressional Cannabis Caucus in a press release. “At a time when there are four million registered medical marijuana patients and many more likely to self-medicate, it is crucial that researchers are able to fully study the health benefits of cannabis. For too long, the federal government has stood in the way of science and progress, creating barriers for researchers obtaining resources and approval to study cannabis.”

The bill would streamline the process by which researchers can apply to study cannabis and removing U.S. Food and Drug Administration (FDA) barriers. The Drug Enforcement Administration (DEA) would be in charge of authorizing manufacturers to produce FDA-developed cannabis drugs, and the Department of Health and Human Services (HHS) would be required to fund studies into the health benefits and potential risks of medical cannabis.

“As a physician who has conducted NIH-sponsored research, I am pleased that this bill has finally passed and that scientists will be able to research what medical marijuana can and cannot do,” said Rep. Andy Harris (R-MD).

But critics of the bill are concerned that a provision written into a previous version of the bill has been removed. Under the new version, research institutions will not be allowed to use samples purchased from state-approved dispensaries.

Under current federal prohibition of cannabis, clinical research of the drug is difficult and marred by poor quality samples. Researchers looking to study cannabis must source their samples from federally-approved producers. In 2021 the Drug Enforcement Agency (DEA) announced that it would be expanding the number of labs that will be approved to grow cannabis for research purposes for the first time. So far that hasn’t happened yet, and scientists are forced to work with cannabis cultivated from a single source: The University of Mississippi.

Samples of cannabis from the university have been recognized as inferior for decades. According to a University of Northern Colorado study pre-printed in bioRxiv, the UM strain shared a closer “genetic affinity with hemp samples in most analyses” compared to commercial cannabis and was lower in both THC and CBD. Some NIDA samples have even reportedly tested positive for mold.

That means that all the clinical data we do have about cannabis is faulty, and the need for increased access for researchers is even more critical than believed.

The research expansion bill is expected to do well in the Senate, where a nearly identical bill was passed in March. But without provisions to allow researchers to access retail-level samples, it will produce useless data.