And he's speaking up now for an important reason.

We're used to seeing him captain a starship but on Thursday, Sir Patrick Stewart wasn't putting on an act as he revealed he uses marijuana to treat his arthritis.

The 76-year-old experienced debilitating pain and had distorted hands up until two years ago, when a doctor in Los Angeles prescribed him cannabis-based products.

According to Daily Mail, Sir Patrick released a powerful statement explaining he was advised cannabis-based spray, ointment and pills might help the ortho-arthritis in his hands, a condition his mother also suffered from.

"I purchased an ointment, spray and edibles," Sir Patrick said.

He continued: "The ointment, while providing some relief from the discomfort, was too greasy to use during daytime and so I only use it at night. It helps with sleep as the pain was reduced."

"The spray, however, is much more usable and I spray my fingers and particularly my thumb joints several times a day."

The admission comes as the veteran actor "enthusiastically" throws his support behind an initiative by Oxford University into cannabis research.

"I believe that the ointment and spray have significantly reduced the stiffness and pain in my hands," Sir Patrick said. I can make fists, which was not the case before I began this treatment."

He added: “I have had no negative side effects from this treatment and the alternative would have been to continue taking NSAID’s, Advil, Aleve and Naproxen, which are known to be harsh on the liver and to cause acid reflux."

The Star Trek actor concluded by saying he believed the programme of research "might result in benefits for people like myself as well as millions of others."