... syndrome, osteoarthritis, rheumatoid arthritis, fibromyalgia, post-traumatic inflammation and pain, heartburn and hyperacidity, headaches and back pain, and allergies. MSM ... is often combined with glucosamine and chondroitin for joint relief and repair.Physiological Functions* As a natural source ... take from 2 - 4 weeks for effects, including pain relief, to be noticed. MSM is remarkably non-toxic. You ...