Advocates say people with epilepsy in Western Australia are the victims of a frustrating Catch-22 situation, forcing many to break the law to access a drug that has been shown to help control seizures.

Bureaucratic approvals have been given for a trial of medical marijuana, but it's proving impossible to locate a reliable supplier of cannabis oil, the critical plant extract.

A Perth epilepsy advocate says WA parents are breaking the law to obtain cannabis oil. Credit:Max Mason Hubers

The Therapeutic Goods Administration has not yet approved any products, both on a local and imported basis.