Peptide Half-Life & Dosing Frequency Explained (2026)

What is half-life?

Half-life is the time it takes for half of a compound to clear. A short half-life means the compound is gone quickly (frequent dosing in research protocols); a long half-life means it lingers (less frequent dosing).

Why it drives dosing frequency

Short-acting peptides — like CJC-1295 without DAC and Ipamorelin — are studied with more frequent administration to maintain a pulsatile signal. Long-acting compounds hold steadier levels with less frequent dosing.

How half-life gets extended

• DAC (Drug Affinity Complex): binds albumin to extend half-life (CJC-1295 with DAC).
• Fatty-acid chains: GLP-1 compounds like Semaglutide use a fatty-acid chain for a once-weekly profile.
• Structural analogs: IGF-1 LR3 is modified to reduce binding-protein affinity and prolong action.

Short vs long-acting at a glance

Related

See reconstitution and storage, and compare any compound on PepsTracker.

Frequently asked questions

What does peptide half-life mean?

Half-life is the time it takes for half of a compound to clear from the system. A short half-life means frequent dosing in research protocols; a long half-life means less frequent dosing.

What is the difference between CJC-1295 with and without DAC for half-life?

DAC binds albumin to greatly extend half-life for steadier levels, while the no-DAC form is short-acting and more pulsatile.

Why is Semaglutide dosed weekly?

Semaglutide includes a fatty-acid chain that extends its half-life, giving it a long-acting, once-weekly research profile.