A House Republican said he's used medical marijuana while in office to combat his arthritis

(CNN)Rep. Dana Rohrabacher is a Republican congressman from California, a senior member on the House Committee on Foreign Affairs and a member of the House Committee on Science, Space and Technology.

He also announced recently that he's a medical marijuana user.

Rohrabacher told a pro-marijuana group this week that he has used medical marijuana while in office to combat his arthritis.

Medical marijuana is legal in 24 states, including California, and Washington. Rohrabacher was part of a bipartisan group of House members that called for Congress to pass a marijuana legalization initiative in 2014.

Rep. Dana Rohrabacher has worked toward marijuana legalization.

Rep. Dana Rohrabacher has worked toward marijuana legalization.

Speaking to NORML, the National Organization for the Reform of Marijuana Laws, Rohrabacher said Tuesday that he used a topical cannabis treatment that got rid of pain he'd been experiencing for over a year.

"I tried it two weeks ago, and it's the first time in a year and a half that I had a decent night's sleep because the arthritis pain was gone," Rohrabacher told the audience, who applauded.

Dr. Sanjay Gupta's "Weed 2: Cannabis Madness"

Rohrabacher says that his arthritis developed after decades of surfing and that he hasn't been able to surf since the pain developed.

"I went to one of these hemp fests in San Bernardino," he told the crowd. "It's a candle, and you light the candle, and the wax is in there, and it melts down, and you rub it on whatever you've got problems with.

"There's definitely cannabis in there, and it makes sure I can sleep now," he said.

Forty-two states have some sort of marijuana legislation, but they vary in degree of legality. In Colorado, both medicinal and recreational use are legal, whereas in Georgia, only cannabidiol oil can be used to treat specific conditions, including ALS, cancer and epilepsy.

Marijuana is composed of 500 chemical compounds including tetrahydrocannabinol, the chemical that can make you high, and CBD, a compound that can quiet electrical and chemical activity in the brain. Studies have found that medical marijuana can reduce pain in patients with arthritis, as well as possibly stall cancer growth, and help treat glaucoma.