Just two weeks after her birth, Harper Howard started experiencing as many as 40 seizures a day. Her parents were baffled, as no one in their family had a history of seizures, and they spent the next nine months traveling the country in search of a doctor who could diagnose their daughter. Finally, it was determined that Harper had CDKL5, a rare genetic disorder that affects just about a thousand people across the world and has no known cure.

"We tried a combination of 10 different drugs," her mother, Penny Howard recalled. "Her life—she was just existing. We had conversations with her, but we had to play both sides and just assume she was in there mentally. She was really trapped. It was horrible."

In 2013, Howard and her husband Dustin saw CNN's "WEED" special, which featured a young girl in Colorado whose similarly frequent and debilitating seizures stopped almost completely after she started taking a tincture that was low in THC, the chemical responsible for most of marijuana's psychoactive effects, but high in CBD, a compound found in cannabis that does not produce a high and is believed by many doctors to provide a number of medical benefits. But the Howards lived in Texas, where medical marijuana reform has been crawling through the legislature, but isn't yet legal.

After some research, however, they discovered that they could purchase CBD oil online. CBD is legal in all 50 states, provided that it's derived from industrial hemp, a strain of cannabis that's legal to import to the United States as long as it doesn't contain any traces of THC. (A handful of U.S. states have legalized hemp cultivation, but farmers have been tentative to actually grow it, fearing resistance from federal drug enforcement.) The Howards ordered a vial of hemp oil from a company called HempMeds, and within two weeks, Harper's seizures had been cut in half, to about 20 a day. After six months, she was seizure free.

Harper died this January from a metabolic complication related to her disorder. But her mother is still touting the benefits of hemp oil: when we spoke with her, she was on the floor of the second annual Cannabis World Congress and Business Expo, which is taking place at the Javits Center through Friday.

"I'm not opposed to doctors or pharmaceuticals—I'm rare here," Howard said, gesturing around the convention floor. "I believe that they saved her life and prolonged it. But when we combined science with nature, we prolonged it another two and a half years, and we gave her a better quality of life. We gave her a quality of life."

Howard's blog about how hemp oil helped her daughter drew the attention of other families coping with CDKL5 across the world, and since 2013, six other countries have legalized CBD oil as a prescription product. Meanwhile, the Howards paid $300 out of pocket for every small vial of oil, as no cannabis-derived products are covered by insurance in the U.S.

Slowly but steadily, however, states have been legalizing marijuana, more often for medical than recreational use. New York State legalized medical marijuana in 2014, with the first dispensaries in the city opening earlier this year, but the state's law notably doesn't allow for the use of the plant itself—just oils and extracts to be vaporized or eaten. As such, there wasn't any actual pot at the expo, and the few exhibitors displaying products with THC had to keep those products sealed behind glass.

The majority of booths hawked legal CBD products, ranging from aromatherapy sprays to lotions and hemp dog treats. Though many, like Howard, spoke of CBD products as something of a miracle cure for everything from seizures to autism and back aches, it's worth noting that when the FDA investigated hemp oil companies last year, it found that many supposed CBD products didn't contain any detectable traces of the cannabinoid.

Among Thursday's exhibitors was CannaKorp, which has created what it calls the "Keurig of cannabis": a pod-based, single-serving vaporizer. The company's partnering with marijuana cultivators, who will fill the pods with their product, to be sold at dispensaries. For about $150, customers can buy the accompanying vaporizer. The product will be rolling out in 2017, first in Colorado and Washington State, both of which have legalized marijuana for both medical and recreational use, but it won't make it to New York until the state legalizes the use of the actual marijuana plant for medical purposes.

Then there were the creators of PotBot, an app that they describe as "the world's first cannabinoid recommendation engine." Users fill out a profile with their age, gender, and weight, and select any conditions they're looking to treat with marijuana. The app will then recommend the ideal dosage of THC to treat that condition, and will display strains of marijuana that can best provide that dosage. It'll also recommend the best way of consuming marijuana for your given condition—for example, vice president Yoray Halevy explained, "if you suffer from inflammation, the best way for you to consume it is most likely vaporization, because that would give you the best relief the quickest. But if you have PTSD you might need tinctures, or you might need edibles." The app will then display the nearest dispensaries, including those that might be out of state, and will also offer a list of doctors registered to prescribe medical marijuana.

By prohibiting the use of the marijuana plant, PotBotics CEO David Goldstein said, New York is keeping some patients from finding the strain that could best treat their conditions: he argued that "with a plant, not only are you getting a lot of whole plant medicine, but just because you have a larger pool of plants you could choose from, there's more opportunity to get the right medicine. It's a much more limited scope when you're working with extracts. You might not find the perfect medicine for you, versus if you're working with plant strains, you can find the right types of strains that work for you."

Like Penny Howard, Shira Adler was inspired to get into the cannabis business by her children: her son has some behavioral problems and trouble sleeping, and it was with him in mind that she created a line of aromatherapy sprays called "Beyond the Spectrum," all of which contain a number of essential oils, including CBD.

"I anticipated parents going, 'Oh, I don't know about putting CBD in something my kids are going to use,'" Adler said. "But ironically, they're like, 'Does it have pot? Can I have some?'"

The sprays won't produce any sort of psychoactive effect—Adler describes the CBD as "putting the essential oils on steroids"—but one of the five, a calming spray titled "Smile," will be sold in select states with THC, targeted specifically at children with autism. Though, like the use of CBD to treat epilepsy, there haven't been any peer-reviewed studies of the oil's efficacy in treating autism, there's anecdotal evidence of children with autism speaking for the first time after taking hemp oil, and some children have reportedly responded even better to a product that also includes THC. But Adler's THC-infused spray won't be sold in New York: autism is not among the few conditions that make patients eligible to obtain medical marijuana.

New York's strict regulations are what's got Ron Silver, owner of Bubby's restaurant in Tribeca, turning his attentions to developing a line of edible marijuana products that he'll soon be rolling out in Oregon, which has legalized recreational marijuana usage. He's taking soda syrups developed at the NYC restaurant and infusing them with THC: one ounce of the syrup carries two milligrams of THC, and users can dilute the syrup with soda water to their preference. Silver's also created a 420-friendly version of 5-hour energy, mixing THC, coconut water, coconut fat, and caffeine; he'll also be rolling out five-pound baker's bars of marijuana-infused chocolate, plus CBD-infused sugars, which can be stirred into tea for a calming sleepytime nightcap.

"I think New York City's laws are insanely stupid and corrupt," Silver said. "But I'm 100% sure the recreational laws will expand here. Otherwise it makes NYC this puritan state, and every other state is reaping the benefits. I don't think New York is going to sit around for that."