Hemorphins are a class of naturally occurring, endogenous opioid peptides which are found in the bloodstream, and are derived from the β-chain of hemoglobin.[1][2] They have antinociceptive effects via activation of the opioid receptors,[2][3] and some may also play a role in blood pressure through inhibition of the angiotensin-converting enzyme (ACE),[4] as well as cause an elevation of endogenous enkephalin levels.[5] Some examples of hemorphins include hemorphin-4, spinorphin, and valorphin.