PRTCL.
Basics & Technique

When should I inject sermorelin?

Updated 2026-05-05

Sermorelin is a growth hormone releasing peptide, and the thinking behind its timing is pretty simple. Your body's largest natural growth hormone pulses happen in the first hour or two of deep sleep, and eating raises insulin and blood sugar, both of which can blunt growth hormone release. Sermorelin also works fast and clears fast, with a half-life of about 11 to 20 minutes, so it acts in one short window rather than lingering. That is the biology people weigh when they think about timing, but the dose, the timing, and whether sermorelin is right for you are decisions to work out with your provider. This app does not prescribe a dose or a schedule. Once you and your provider settle on a dose, the reconstitution calculator can help you convert your own dose into syringe units.

IfIf you just ate a big meal
Thenthen remember that high insulin and blood sugar can blunt growth hormone release, and your provider can help you plan around meals
IfIf you train at night
Thenthen ask your provider how workouts and sermorelin best fit together for you
IfIf you wake up groggy or have dreams that disturb your sleep
Thenthen mention it to your provider, who can help you adjust your plan
IfIf nighttime dosing does not fit your schedule
Thenthen talk to your provider about timing that works for you
Key facts
  • Sermorelin's half-life is about 11 to 20 minutes, so it acts in a single short pulse
  • The largest natural growth hormone pulses happen in the first hour or two of deep sleep
  • High insulin and high blood sugar both blunt growth hormone release
  • Sermorelin was approved in the US under the brand Geref in 1997 for pediatric growth hormone deficiency; the brand was discontinued in 2008 for business reasons, not safety
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