The term medical marijuana is a misnomer. While it’s been handed out to more than a million so-called patients in 23 states, marijuana bears no resemblance to anything else in their medicine cabinets. Its use is not well-regulated or -understood, and states have done a poor job of tracking what, exactly, is being doled out at its dispensaries.

The situation puts the state health agencies that oversee medical marijuana and practicing physicians whose patients request it in the awkward position of distributing an unproven and largely unregulated substance for medical use. Anecdotes and limited evidence have shown the compounds within marijuana likely hold some potential for treating a few medical conditions, including pain and epilepsy. Partly because of federal restrictions on research, scientific consensus on the benefits and safety of medical marijuana has puttered at a far slower pace than either its political appeal or its popular favor.

A U.S. Senate bill introduced Tuesday would grant easier access to researchers who could support or refute marijuana’s medical legitimacy, while simultaneously endorsing the many treatments for which it is already being used. Meanwhile, the drug is neither approved nor regulated for medical use by any federal government agency, so the responsibility for overseeing medical marijuana has largely fallen to states.

States frequently do regulate medical-marijuana dispensaries, but these regulations tend to cover everything but the drug itself. State regulations require background checks for dispensary operators, but rarely mandate such checks for the product to standardize dosages, provide the frequency at which a dose should be taken or ensure the quality of the strains that are administered. Oregon requires its medical-marijuana dispensaries to test for pesticides, mold and mildew, while New Mexico requires testing for quality, purity and consistency of dosage, but these stipulations constitute the exceptions rather than the rule when it comes to medical-marijuana regulation. And physicians are calling on the government to do more.

“Right now, if you go and get medical marijuana from a dispensary -- there’s no standardization,” says Dr. Seth Ammerman, a clinical professor of pediatrics at the Stanford School of Medicine who contributed to a recent statement by the American Academy of Pediatrics calling for a closer look at the medical potential of marijuana.

“A big problem is that it comes from a plant, and plants are not as consistent as laboratories,” says Dr. Shaun Hussain, a pediatric specialist in epilepsy at the University of California at Los Angeles Medical Center who treats patients who are also using marijuana extracts.

Dr. Larry Wolk, executive director and chief medical officer of the Colorado Department of Public Health and Environment, points out the discrepancies in his own state, where dispensaries handing out recreational marijuana must test their products for potency and contaminants through independent labs. Dispensaries that administer medical marijuana are not subject to any such scrutiny. “You’re theoretically safer purchasing the recreational legal products than the medical products,” he says.

Even if states attempted to enforce standards for dosage and quality, they’d be hard-pressed to find the scientific evidence to back them up. Researchers have not studied medical marijuana to the extent that it’s possible for them to certify it is safe or offer recommendations for how marijuana should be handed out for different conditions. Physicians who recommend it -- they can’t actually prescribe it because it’s not an approved medicine -- may suggest a particular strain, but a patient’s medical-marijuana card includes no such specifications. That leaves it to the dispensary staff to largely assume responsibility for a patient’s treatment.

Regardless of what states decide, marijuana is certainly no medicine in the eyes of the U.S. government, even while Congress considers endorsing it as one. The drug remains illegal, classified as a Schedule I substance, which is the most restrictive class of drugs described by the Drug Enforcement Administration. The so-called medicine typically handed out in medical-marijuana dispensaries -- the dried buds of a plant that are rolled into joints and smoked, or extracts that are concentrated into oils -- have not been subject to the review that is customary for all medicines OK’d by the Food and Drug Administration.

“As far as classifying it as a medicine, the work still needs to be done,” says Dr. Mahmoud A. ElSohly, a professor of pharmaceutics at the University of Mississippi who runs the federal government’s marijuana farm.

FDA approval would admittedly be a high bar for marijuana to reach. The agency regulates most herbal remedies comparatively loosely as dietary supplements, and the marijuana handed out at dispensaries more closely resembles remedies such as echinacea or St. John’s wort than it does prescription drugs. Purveyors of these substances do not need to prove efficacy or safety, but they must avoid claims that their products can prevent, treat or cure any disease.

The FDA’s approval process is not really set up to consider plants as potential medicines, due to the fact they contain a wide variety of active ingredients in varying amounts. To receive agency approval, each compound within marijuana would likely need to be isolated and reviewed for it to be rendered appropriate as a medicine. A handful of drugs such as Marinol are based on marijuana compounds and have already undergone this lengthy process, winning approval by the agency.

Experts are also concerned that the potential harm of marijuana is not yet fully understood. The American Lung Association points out that marijuana contains 33 cancer-causing chemicals, and smoking it causes four times as much tar to build up in a user’s lungs as does smoking tobacco, as joints often do not contain the filters that are required for cigarettes. Officials in Colorado are also concerned that since medical marijuana was legalized there in 2000 it has led to an increase in impaired driving and posed a threat to kids who get their hands on it, according to an article published in the New England Journal of Medicine Thursday.

Despite the lack of regulatory oversight of medical marijuana, public and political support for it is at an all-time high. However, researchers say that for medical marijuana to gain true legitimacy as a safe and effective treatment, they need to better understand its effects. The new Senate bill may help by switching the designation of marijuana to a Schedule II from a Schedule I substance, which would give researchers the ability to experiment with it and create new facilities that could grow marijuana for research. These measures could bring marijuana one step closer to resembling something like a medicine, more than a decade after its first so-called patients took their initial puffs.