Question 1

What is a peptide's half-life?

Accepted Answer

Half-life (t½) is the time it takes for plasma concentration to fall to 50% of its peak. After 5 half-lives, ~97% has been eliminated. For peptides this typically ranges from minutes (DSIP, sermorelin, CJC-1295 without DAC) to days (semaglutide, tirzepatide, retatrutide).

Question 2

Why is plasma half-life different from effect duration?

Accepted Answer

Many peptides act on receptors or downstream pathways that persist long after plasma clearance. DSIP and Epitalon have minute-scale plasma t½ but cycled effect over days. MT-II's plasma t½ is ~33 hours but pigment effect outlasts. The chart shows plasma decay, not effect.

Question 3

How do I use the multi-peptide overlay?

Accepted Answer

Add two or more peptides, say CJC-1295 (no DAC, 30-min t½) and Ipamorelin (2-hr t½), and watch the curves diverge. By hour 4, CJC is ~3% but Ipamorelin is still ~25%. This is why the GH stack is dosed at the same moment.

Question 4

What's the difference between CJC-1295 with DAC and without?

Accepted Answer

Without DAC: ~30 min plasma half-life, pulse dose. With DAC (drug affinity complex): ~6–8 day half-life, once-weekly. The chart includes both for direct comparison.

Peptide Half-Life Decay Visualizer

Half-Life Decay Viz

Frequently asked questions

Educational use only

Half-Life Decay Viz

Frequently asked questions

What is a peptide's half-life?+

Why is plasma half-life different from effect duration?+

How do I use the multi-peptide overlay?+

What's the difference between CJC-1295 with DAC and without?+

Educational use only