Humanin is an endogenous peptide that exhibits anti-apoptotic and neuroprotective activities. Humanin is overexpressed in some cancers and could possibly be used as a biomarker. In neurons undergoing ischemia/reperfusion, humanin decreases levels of lactate dehydrogenase and malondialdehyde, decreases the formation of karyopyknotic nuclei, and increases the activity of superoxide dismutase (SOD), increasing cell viability and survival. In other cellular models, humanin activates formyl peptide receptor-like receptors 1 and 2 (FPRL1/2), inhibiting Bax-dependent apoptosis and suppressing JNK-mediated cell death. Humanin also inhibits amyloid-β (Aβ)-induced neuronal death in vitro and its effects in animal models of Alzheimer’s disease.