Voltaren Emulgel contains the active substance diclofenac which belongs to a group of medicines called non-steroidal anti-inflammatory drugs (NSAIDs). It is specially formulated for rubbing into the skin and used to relieve pain and reduce inflammation and swelling in painful conditions affecting the joints and muscles. Voltarol Emulgel/Voltaren Emulgel can be used to treat: • muscle and joint injuries (e.g. sprains, strains, bruises, backache, sports injuries) • tendonitis (e.g. tennis elbow) • osteoarthritis.