Humanin half-life & pharmacokinetics

Reported half-life

Approximately 30 minutes plasma half-life for native humanin after subcutaneous administration; S14G-humanin (a synthetic analogue with a serine-to-glycine substitution at position 14) has substantially extended half-life through improved metabolic stability. Tissue retention in brain and other target tissues exceeds plasma exposure. The S14G analogue is 1000-fold more potent than native humanin on cytoprotective endpoints.

The half-life and pharmacokinetic profile of Humanin reported above is drawn from the published pre-clinical literature. Plasma half-life describes the time taken for the circulating concentration to fall by half after a single dose; tissue half-life — which may be longer for peptides retained in specific organs or matrices — is a distinct and often more relevant parameter for healing research, where the duration of exposure at the injury site matters more than the systemic exposure profile.

Routes of administration studied

• Subcutaneous injection (research; standard route)
• Intracerebroventricular injection (pre-clinical CNS research)
• Intranasal (research applications requiring CNS access)

Different routes produce materially different pharmacokinetic profiles for the same peptide. Subcutaneous administration generally produces flatter, more sustained plasma profiles than intravenous bolus dosing; intraperitoneal administration (common in rodent models) is not directly translatable to human routes; oral administration faces the additional challenge of luminal and brush-border peptidase degradation, which is why most research peptides have very low oral bioavailability without protective formulation.

Drug class

Mitochondrial-derived peptide (MDP); endogenous 24-amino-acid peptide encoded by the mitochondrial 16S rRNA region; cytoprotective and metabolic-regulatory signalling molecule.

Mechanism context

Half-life interpretation depends on the underlying mechanism. Humanin acts as follows:

Humanin is a 24-amino-acid endogenous peptide encoded by an open reading frame within the mitochondrial 16S rRNA gene (MTRNR2). It was discovered by Yuichi Hashimoto and colleagues at Keio University in 2003 through a functional cDNA library screen for peptides protecting neuronal culture from β-amyloid (Aβ)-induced cytotoxicity — the seminal identification of mitochondrial-derived peptides (MDPs) as a bioactive protein class distinct from the more familiar nuclear-genome-encoded peptides. Humanin translation occurs on mitochondrial ribosomes; the mature peptide is either retained in the cytoplasm or exported to plasma, where it exerts endocrine effects on distant tissues.

See the full Humanin research profile for the complete mechanism summary, history, study citations, and references.

Practical considerations

Short plasma half-life does not necessarily mean short duration of biological effect. Many peptides — including BPC-157, GHK-Cu, and the thymosin-derived compounds — exhibit tissue retention or mechanistic effects (gene expression, signalling cascades) that outlast plasma exposure by hours to days. The pharmacological half-life and the biological-effect half-life are distinct parameters that must both be specified in any rigorous research design. Repeated-dose protocols should account for accumulation only where tissue half-life is genuinely long; for most peptides with short plasma half-life and rapid degradation, accumulation is not a practical concern.

For dose ranges in published research, see the dosing reference page. For reconstitution guidance, see the reconstitution reference page.