Short answer: nothing, really. Cannabis labeled as medical is very often the exact same product as that labeled as adult-use.
If there is no difference, then why even have medical cannabis? Well, there are a few distinctions worth noting.
Generally speaking, a medical cannabis program in and of itself is more regulated than an adult-use program. This regulation can be in many forms such as the eligible qualifying conditions to become a patient, type of products available for purchase, limits on the percentage of THC in products, and who can recommend patients for medical cannabis. All of these restrictions limit who may be able to legally access cannabis, as opposed to allowing everyone of age to legally access it.
On the flip side, there may be some benefits to being a medical cannabis patient such as the ability to home grow (a major plus in states that allow it), lower taxes on products, the ability to purchase larger quantities of product, and purchasing priority from dispensaries (in states that also allow for adult-use).
As noted above, the types of products available as medical cannabis may (but not always) be more limited than those available as adult-use cannabis. Various states have placed restrictions on items such as edibles and concentrates, thereby allowing patients access to only a select portion of the countless products available. Furthermore, there are certain products that are geared more towards medical cannabis patients. These include tinctures, suppositories, and certain concentrates (such as RSO) that may be able to help patients with symptoms related to certain conditions.
At the end of the day, we like to think that many who consume cannabis are doing so to achieve some specific health and/or wellness-related outcome. Whether it be for pain relief, aid with sleep or relaxation, assist with an anxious situation, or just for a burst of energy, there is often a reason one chooses to consume.
It is also important to note that just because a state implements or transitions from a medical-only to adult-use market doesn’t mean that conditions affecting so many medical patients cease to exist. While the bright lights of an adult-use program are enticing, it is critical to ensure that those who need cannabis as a safe, alternative choice for medicine are not forgotten.