While TENS units provide effective treatment of a number of medical conditions, products like hot/cold therapy, topical treatments, light-therapy and other products can also help. TENS units may be purchased at your local drugstore or chiropractic office or online. Check with a reliable and trusted source to purchase a unit locally or look online for established companies. One of the oldest online providers sells TENS units, additional electrodes, gels and other medical supplies to help with a variety of conditions. Also check with ElectroTherapy.org for medical supply guides.