Sermorelin is a shorter-acting GHRH analog with a half-life of minutes, while CJC-1295 (Modified GRF 1-29) lasts several hours, allowing less frequent dosing.
Clinical trials show both effectively stimulate GH release, but CJC-1295's longer duration makes it more practical for muscle-building protocols. Sermorelin requires more frequent injections (3-4x daily) compared to CJC-1295's 1-2x daily schedule.