Backed by decades of research, Zostrix® works by depleting how much Substance P is stored in the sensory nerve endings. Substance P is a compound in the nerves responsible for transmitting pain signals. The result? Relief that improves with regular use. Whether you're seeking effective relief of pain associated with arthritis, Diabetic Neuropathy or for post-herpetic neuralgia (pain following shingles), Zostrix® provides an over the counter, naturally derived alternative.