Buy Gabapentin online is an anti-epileptic medication, also called an anticonvulsant. It affects chemicals and nerves in the body that are involved in the cause of seizures and some types of pain. Gabapentin is used in adults to treat nerve pain caused by herpes virus or shingles (herpes zoster).The Horizant brand is also used to treat restless legs syndrome (RLS).The Neurontin brand is also used to treat seizures in adults and children who are at least 3 years old.