Patrick Stewart has revealed that he uses medicinal marijuana spray, ointment and edibles every day to help treat arthritis in his hands.

The 76-year-old Logan actor opened up about his use of cannabis as he praised the U.K.’s first initiative to explore the benefits of marijuana in research led by Oxford University.

“I have had no negative side effects from this treatment,” he said in the statement obtained by PEOPLE, noting that using marijuana has “significantly reduced the stiffness and pain” in his hands.

Stewart said that just two years ago, a Los Angeles doctor gave him legal permission to purchase cannabis-based products from a “registered outlet” to help with his condition.

The actor uses the ointment each night to help with the pain in his hands so he can sleep better, he said, noting that it’s “too greasy” to use during the day.