Hemopressin TFA, a nonapeptide originating from the α1-chain of hemoglobin and initially isolated from rat brain homogenates, is an orally active, selective inverse agonist of CB1 cannabinoid receptors that demonstrates antinociceptive effects in inflammatory pain models [1] [2].

Hemopressin TFA induces hypotension in anesthetized rats and undergoes metabolism by endopeptidase 24.15 (EP24.15), neurolysin (EP24.16), and angiotensin-converting enzyme (ACE) in both in vivo and in vitro conditions [1]. When administered orally, it mitigates mechanical hyperalgesia in CCI-rats for up to 6 hours and reduces Egr-1 immunoreactivity (Egr-1Ir) in the dorsal horn's superficial layer within the spinal cord of CCI rats [2].