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OtherEvidence B3 cited

Apelin

aka APLN · apelin-13 · apelin-36 · APJ ligand

A peptide ligand for the APJ receptor (APLNR) with potent cardiovascular, metabolic, and anti-aging effects. Apelin levels decline with aging and are reduced in cardiovascular disease.

Molecular wt
1550.8g/mol
Formula
C69H111N23O16S
CAS
217082-58-1
Half-life
5 min
clinical
Tmax
30 min
Route
Subcutaneous injection
PubChem
25078060

Sequence

One-letter13 residues

QRPRLSHKGPMPF

Three-letter

Gln-Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Met-Pro-Phe

Read this before quoting the sequence
'Apelin' is a family, not one peptide. The 77-residue human preproapelin (UniProt Q9ULZ1) is processed to apelin-36 (res. 42-77), apelin-31, apelin-28 and apelin-13 (res. 65-77). The sequence given here is apelin-13, which is what the ported CAS number (217082-58-1) identifies. The dominant circulating/most-studied form in the human trials cited is the pyroglutamated variant [Pyr1]apelin-13, in which the N-terminal Gln is cyclised to pyroglutamate.
Source ↗

Mechanism of action

Apelin binds to the APJ receptor (a G-protein coupled receptor) and activates multiple downstream pathways including PI3K/Akt, AMPK, and eNOS. In the cardiovascular system, apelin is a potent vasodilator, positive inotrope (increases cardiac contractility without increasing heart rate), and reduces blood pressure. It also enhances glucose uptake in muscle, reduces insulin resistance, promotes angiogenesis, and has anti-fibrotic properties. Apelin/APJ signaling declines with age.

What the evidence actually shows

Grade B

Strong preclinical evidence for cardiovascular protection and metabolic benefits. Human observational studies confirm apelin decline in heart failure and aging. Limited interventional human data. APJ receptor agonists are in pharmaceutical development.

Regulatory status

Status
Not an approved drug in any jurisdiction identified. Apelin peptides have been used in investigator-led acute human physiology studies only.
Clinical stage
Acute-infusion human mechanistic studies (published); no approved indication.
Source ↗

Pharmacokinetics

Half-life
5 min
Tmax
30 min
Absorption
subcutaneous
Elimination
renal
Washout
1 days
Low-confidence pharmacokinetics
These figures are recorded as clinical rather than measured in a published PK study. Treat them as an order of magnitude. Anything downstream of them — accumulation, steady state, washout — inherits that uncertainty.

Dosing — what backs each figure

Apelin has been given to humans only as an acute intravenous infusion in cardiovascular and renal physiology studies — typically [Pyr1]apelin-13 at 1-300 nmol/min, with the longest exposure being a single 6-hour infusion. Its plasma half-life is a few minutes, so there is no repeat-dose, self-administered or take-home regimen for apelin in any published source, and no therapeutic dose has been established.

ClinicalApproved labelling or a published human trial
PreclinicalAnimal studies — not a human dose

  • Continuous infusion of apelin at 0.01 mcg/min for 20 minutes; increased Pmax and max dP/dt in native and failing hearts

    rat (native and post-LAD-ligation heart failure) · intravenous infusion · PMID 15364861

Animal doses do not convert to human doses by body weight alone. Route matters too — a compound dosed intraperitoneally in mice tells you little about subcutaneous use.

No established human dose
No approved label or completed human trial establishes a dosing regimen for this compound. Anything presented as a standard protocol for it — anywhere — is someone's convention rather than a finding.

Handling and storage

No compound-specific stability data exists
No stability/storage study for apelin peptides was located in a primary or regulatory source. Apelin-13 contains a methionine (a chemically oxidation-prone residue, verified from the PubChem formula/structure) and has an extremely short circulating half-life in humans, but neither observation is a substitute for a measured storage stability figure. No compound-specific stability study (lyophilised or reconstituted) was located in a primary/regulatory source during this verification pass. Only generic synthetic-peptide handling guidance exists for this compound; no specific temperatures or durations are recorded here rather than fabricating them. General peptide handling still applies — reconstitute gently, keep it cold, keep it dark — but any specific figure you see quoted for this compound elsewhere is someone's assumption, not a measurement.
→ Reconstitution walkthrough→ Reconstitution calculator

Safety

References (3)

Data provenance

Chemistry and citations on this page were checked against primary sources on 2026-08-14. Values that could not be verified were left blank rather than filled with a plausible guess.

Could not verify
storage.lyophilized, storage.reconstituted, storage.lightSensitive, reconstitution.solvent, regulatory.wada

Research use only
This profile is educational reference material. It is not medical advice, not a prescription, and not an endorsement of self-administration. Compounds discussed here are research chemicals and most are not approved for human therapeutic use.

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