Hemp Door, CBD/MSM/Arnica Cream 500mg - This works the best of the many products I've tried for pain associated with arthritis of the knee, and my wife uses it on her back with similar success. The only downside is that it is a cream that requires you rub it in and more messy to apply than most the sprays. That being said I have found that after applying it if I keep it on for about 5 minutes and then wipe any residual cream off with a dry washcloth what is left when you feel the knee is similar to what you'd feel if you used a spray. All and all I give it 5 stars.