Salonpas includes both lidocaine products and general topical analgesics containing menthol and camphor. Salonpas products with lidocaine and benzyl alcohol work by desensitizing the nerves to numb away the pain, while the Salonpas Pain Relief Patch contains a non-steroidal anti-inflammatory drug (NSAID) called methyl salicylate. Voltaren Arthritis Pain Gel also contains an NSAID called diclofenac sodium. It works by temporarily blocking the production of pain-signaling chemicals called prostaglandins. However, unlike Salonpas products, Voltaren is a full prescription strength gel that is available over-the counter (OTC). In addition, Voltaren is FDA-approved to be used daily for 21 days in a row before consulting a doctor, while products like Salonpas Pain Relief Patch are approved for 3 days of use before consulting a doctor.