For people managing chronic pain, epilepsy, anxiety, or cancer, a prescription for medical marijuana may feel like a lifeline. In more than half of the United States, it is. But what happens when that patient leaves their home state with their medication in hand? The answer underscores a deep and often misunderstood constitutional issue: the tension between state medical marijuana laws and the Full Faith and Credit Clause of the U.S. Constitution.

The Full Faith and Credit Clause is found in Article IV, Section 1 of the United States Constitution. It requires each state to recognize the “public acts, records, and judicial proceedings” of every other state. In practice, this means that a marriage, court judgment, or business license recognized in one state is generally recognized in another. But the clause has limits. It doesn’t require one state to apply another state’s laws in violation of its own public policy. And that’s where medical marijuana laws hit a wall.

Medical marijuana laws are state-based exceptions to both federal and other state laws criminalizing marijuana possession. A doctor in California may lawfully prescribe cannabis to a patient under California law, but that same prescription carries no legal weight in Georgia or Texas if those states prohibit marijuana outright—even for medical purposes. While one might think the Full Faith and Credit Clause would protect the patient’s right to travel with their medicine, courts have routinely held that states are not required to enforce another state’s laws when doing so would contravene their own deeply held public policies. Since marijuana remains a Schedule I substance under federal law, and because some states continue to criminalize it, there is no constitutional obligation to honor out-of-state medical marijuana authorizations.

Contrast that with a prescription for oxycodone. Oxycodone is a Schedule II controlled substance under the federal Controlled Substances Act. While heavily regulated, it is legal when prescribed by a licensed physician and dispensed through a pharmacy in any state. Because it is federally legal when prescribed, patients can travel with their medication nationwide, provided they carry it in its original prescription bottle and use it as directed. There’s no state in the U.S. where a properly prescribed oxycodone tablet becomes an illegal drug simply because a person crosses a state line. The key distinction: Oxycodone is regulated and accepted under federal law; marijuana, even when prescribed by a doctor, is not.

Even more concerning, transporting medical marijuana across state lines—even between two states where it is legal—can expose patients to federal prosecution for drug trafficking. Under federal law, the interstate transportation of marijuana remains a felony offense. A cancer patient driving from Colorado to New Mexico with their legally prescribed edibles in the trunk may be committing a federal crime the moment they cross state lines, despite being in compliance with both states’ laws.

At the same time, that same patient could also face state-level charges if they drive into a jurisdiction that does not recognize out-of-state marijuana prescriptions. In states with no medical marijuana program, possession remains illegal regardless of the source or purpose. The result? A patient can go from legal to criminal in the space of a mile.

Until there is federal reform, patients relying on medical marijuana must navigate a confusing and risky legal landscape. Those traveling out of state should never assume their prescription is valid elsewhere. Even flying with medical marijuana—even with a doctor’s note—can trigger serious consequences at TSA checkpoints, which are under federal jurisdiction.

The Full Faith and Credit Clause does not shield medical marijuana users from criminal liability in states that reject cannabis as a legal medicine. Unlike federally recognized prescriptions like oxycodone, marijuana remains a federally illegal substance. That legal distinction carves a deep divide between rights recognized in one state and crimes prosecuted in another. Until federal law catches up to medical science and modern public opinion, patients must tread carefully—because what’s medicine in one place may be contraband in another.

For now, patients should consult with an experienced attorney before traveling across state lines with cannabis. In some cases, it may be safer to leave the medication behind than risk arrest and prosecution.

What Is Permitted in Georgia?

In Georgia, the legal landscape for medical cannabis is notably restrictive. The state permits the use of low-THC oil for certain medical conditions, but this allowance comes with stringent limitations.​

Under Georgia law, patients and caregivers registered with the state’s Low THC Oil Registry are authorized to possess up to 20 fluid ounces of low-THC oil. This oil must contain no more than 5% THC by weight and an equal or greater amount of cannabidiol (CBD). The registry is managed by the Georgia Department of Public Health, and eligibility is confined to Georgia residents diagnosed with specific qualifying conditions, such as severe or end-stage cancer, epilepsy, Parkinson’s disease, and others. ​

Importantly, the law does not legalize the possession of marijuana in leaf form, nor does it permit the sale or use of food products infused with low-THC oil or the ingestion of low-THC oil through vapor. Physicians in Georgia do not prescribe marijuana; instead, they may certify patients for the Low THC Oil Registry. ​

Possession of any form of marijuana by individuals not authorized through the Low THC Oil Registry remains illegal under both state and federal law. This includes marijuana in plant form, edibles, and any cannabis products exceeding the 5% THC threshold. Even for registered patients, transporting low-THC oil across state lines can expose them to federal charges, as marijuana remains a Schedule I controlled substance under federal law.​

Furthermore, while some Georgia cities have decriminalized possession of small amounts of marijuana (listed below), these local ordinances do not override state law. Therefore, individuals found in possession of unauthorized cannabis products can still face state-level charges. ​

Georgia’s medical cannabis laws are narrowly tailored, allowing only specific patients to possess limited quantities of low-THC oil. The state does not recognize medical marijuana prescriptions from other states, and unauthorized possession of cannabis products remains a criminal offense. Patients and caregivers should exercise caution and ensure compliance with state regulations to avoid legal repercussions.