By now, many people have heard of Charlotte Figi, the little girl from Colorado who used medical cannabis oil to dramatically reduce the number of seizures she suffered. Her story was made famous on CNN, and it popularized a strain of cannabis called Charlotte’s Web.

Charlotte’s Web is unique because it is very low in delta-9-tetrahydrocannabinol (THC) and high in cannabidiol (CBD). Delta-9-tetrahydrocannabinol is the psychoactive compound in cannabis that gives the user the “high” feeling. Cannabidiol is another compound found in cannabis that has gained recognition for its medicinal benefits without the psychoactive effects.

Although Charlotte has spread awareness for the medicinal use of cannabis to treat epilepsy, there are many others with similar stories. Austin Roberts is a 12-year-old boy who was having 200 seizures per month. When he started using cannabis, his seizures decreased dramatically, and his mood, appetite, and energy levels improved.

Tim Shellman is 29 years old and his seizures began when he was 15. He started smoking cannabis shortly after developing the condition and quickly realized that smoking controlled his seizures.

At 17, he was seizure-free for eight months while he had consistent access to cannabis. Unfortunately, medical cannabis is not legal in his state and he has difficulty finding someone who can supply his medicine.

When he is unable to secure a supply, the seizures return. Shellman has used nine different seizure medications in a variety of combinations, but his body is resistant to them. Cannabis is the only thing that controls or stops his seizures.

Until the last few years, studies on cannabis were hard to come by due to federal law. Now that more than half of the United States has legalized medical cannabis, and a handful of states have legalized it recreationally, there have been more studies on the medicinal effects of this powerful herb.

Dr. Orrin Devinsky, who specializes in epilepsy and neurology, is the director of NYU Langone’s Comprehensive Epilepsy Center. The center not only treats patients with the most cutting-edge treatments, but they are also leaders in epilepsy research. Dr. Devinsky sees medical cannabis as a promising treatment for epilepsy.

“We don’t today know exactly how CBD exerts its biological effects, which include, in animal models, very potent anticonvulsant or anti-seizure effects in numerous species and in numerous different models of epilepsy,” he says. “And interestingly, in none of the animal models that have been looked at to date has CBD been actively causing seizures, and in the majority of them, it is quite effective as an anti-seizure agent.

“By contrast, THC…is also an important and potential anti-epileptic drug based on our animal experience because in most animal studies, THC also exerts anti-seizure properties. However, in about 10 per cent of the animal models, THC can actually lead to more seizure activity or more seizure severity. So, it is something to keep in mind that THC and CBD are really quite different, both in how they act in the brain and, potentially, how they affect different types of epilepsies. We still don’t have really good clinical scientific data from humans, but we have quite good data in animals.”

Many studies point to the benefits of cannabis, and particularly CBD, in treating seizures. In 1978, nine patients were randomized to receive either 200 mg per day of pure CBD or a placebo for three months (Mechoulam and Carlini 1978). Two of the four patients receiving CBD became seizure-free, while there was no change in the five placebo recipients.

In 1981, 15 adult patients were enrolled in a double-blind, placebo-controlled study to examine the effect of CBD for 18 weeks (Carlini and Cunha 1981). These patients exhibited partial seizures with secondary generalization. Of the eight patients who received CBD, four became seizure-free, one “improved markedly,” one “improved somewhat,” one showed no improvement, and one withdrew from the study.

A retrospective case review of 75 pediatric epilepsy patients was performed by researchers at Children’s Hospital Colorado. Each patient used a form of cannabis extract containing CBD. Researchers found that 57 per cent had some seizure reduction, while 33 per cent had a reduction of 50 per cent or more.

In March 2017, Mexican researchers used a pure CBD oil to successfully reduce seizures in patients with Lennox-Gastaut Syndrome, a rare form of epilepsy. Of the study’s 38 patients, 86 per cent reported a 50 per cent reduction in motor seizures, 55 per cent had a 75 per cent decrease in overall seizures, and 13 per cent experienced complete seizure remission after four months of treatment. Nobody reported negative side effects.

There are many types of epilepsy and many different strains of cannabis with varying amounts of THC and CBD, so it may take time to find the correct strain and dosage for each individual situation. While most doctors recommend trying pharmaceuticals first, many see cannabis as beneficial to patients who are drug resistant and recommend they find a strain high in CBD and low in THC for best results.

Charlotte’s Web and Haleigh’s Hope are two well-known, high-CBD strains developed in Colorado. A British company, GW Pharmaceuticals, has created Epidiolex, which contains almost pure CBD and will file a new drug application with the FDA in the first half of 2017.

CBD is generally taken in the form of tinctures, capsules, oils, and patches. The Mayo Clinic recommends taking 200-300 mg of CBD by mouth daily for up to 18 weeks. Some patients find success with a combination of pharmaceuticals and cannabis. It is important to work closely with your doctor to create a treatment plan suited specifically to your needs.