Product Short Description: SALICIN YELLOW Product Description: Its active ingredient, salicin, reduces the production of pain-inducing chemicals in your nerves. Limited evidence suggests that willow bark may have a moderate effect in treating pain caused by osteoarthritis and rheumatoid arthritis. Its active ingredient, salicin, reduces the production of pain-inducing chemicals in your nerves. Limited evidence suggests that willow bark may have a moderate effect in treating pain caused by osteoarthritis and rheumatoid arthritis.