Voltaren Emulgel Extra Strength contains the non-steroidal anti-inflammatory drug (NSAID), diclofenac diethylamine. Diclofenac diethylamine works to relieve pain and reduce inflammation (swelling). The technology in Voltaren Emulgel Extra Strength helps the gel to penetrate deeply into the skin to deliver diclofenac diethylamine to the site of pain. Voltaren Emulgel Extra Strength can be applied twice daily (morning and evening) to last up to a day. The gel is absorbed through the skin and creates a reservoir of diclofenac diethylamine under the skin when applied regularly, from where the drug is released slowly over the course of time for the relief of pain and inflammation.