RSO experiences... Has anyone tried it to manage chronic pain?

My Mother has Rheumatoid and Osteoarthritis which causes excruciating pain which is very debilitating when it sets in and she has a flare up which can set in any part of the body/ joints.

She has had no choice now but to go on methotrexate injections to “ Try” to control the pain even though we’ve known the side effects and were very against it. A friend of mine in Hutchinson, Kansas recommended she try it and I had never heard of it , only the CBD oil which did nothing to help .

Any feedback would be greatly appreciated. Thanks everyone.