A modified version of THC stays completely dormant in the bloodstream until a beam of light flips it on to stop a seizure.
Azo-THC-3 is a light-sensitive molecule designed to treat epilepsy with surgical precision. Traditional cannabis-based drugs flood the entire brain, which often leads to heavy sedation and lethargy for the patient. This new compound only activates when it is hit with specific wavelengths of UV light at the exact location where a seizure begins. This approach allows for the suppression of brain electrical storms without affecting any other regions of the mind or body. Doctors could eventually use this technology to treat focal epilepsy with zero systemic side effects. It turns a standard drug into a targeted tool that only works where and when it is needed.
A photoswitchable cannabinoid for precision treatment of refractory seizures in a mouse epilepsy model
bioRxiv · 10.64898/2026.05.04.720358
Temporal lobe epilepsy (TLE) has an unmet need for precision treatments targeting the seizure focus while avoiding effects on other body parts to minimise side effects. Photopharmacology could enable precision treatment by combining systemic administration of a photoswitchable drug with implantation of an optic fibre in the epileptic focus to induce light-dependent drug conversion from an inactive to an active configuration that interacts with its target receptor to suppress seizures. The photos