Mambalgin-1, originally isolated from black mamba venom, is a 57-residue peptide containing four disulfide bonds. Mambalgin-1 has been shown to inhibit the acid-sensing ion channels, ASIC-1a, ASIC-2a, and heteromultimers of these two channel subunits; acid-sensing ion channels play a major role in pain pathways. Mambalgin-1 suppresses activity in central neurons and peripheral nociceptors, thus blocking pain. Its analgesic effect was not toxic in mice. Mambalgin-1 is available in 0.5 mg and 1.0 mg.