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Recovery & Performance PeptidesRecovery research and practical context
Source comparison

Sermorelin Timing: Morning vs Night Comparison

Morning (fasted, pre-breakfast) Poor. Daytime GH pulses are small and irregular, accounting for <30% of daily output High. Cortisol peaks in morning (15–25 µg/dL), insulin rises post-meal, both suppress GH signalling Moderate. GHRH receptors functional but dow

This comparison does not assign a generated winner or score.

  • Morning (fasted, pre-breakfast)
  • Poor. Daytime GH pulses are small and irregular, accounting for <30% of daily output
  • High. Cortisol peaks in morning (15–25 µg/dL), insulin rises post-meal, both suppress GH signalling
  • Moderate. GHRH receptors functional but downstream pathways inhibited by cortisol and feeding
  • Convenient. Fits standard daily routines, no sleep timing required
  • Suboptimal. Morning administration misses the nocturnal GH pulse window entirely and works against cortisol-driven suppression. May produce mild IGF-1 elevation but significantly lower than nighttime dosing.
  • Evening (3–4 hours post-meal, 60 min pre-sleep)
  • Excellent. Aligns with nocturnal GH pulse during slow-wave sleep, which accounts for 60–70% of daily GH secretion
  • Low. Cortisol at daily nadir (<5 µg/dL), insulin cleared, fasted state removes metabolic inhibition
  • High. GHRH receptors at peak sensitivity during SWS, minimal somatostatin interference
  • Requires planning. Must time meal, fasting window, and sleep onset to avoid suppression
  • Optimal. Nighttime administration leverages circadian GH peak, maximises receptor sensitivity, and produces the highest integrated GH response. This is the evidence-based standard.
  • Immediately post-meal (any time)
  • Poor. Feeding-induced insulin and free fatty acids suppress GH release for 2–3 hours regardless of time of day
  • Very high. Insulin spike (50–100 µU/mL) triggers somatostatin release and GHRH inhibition, free fatty acids block pituitary GH secretion
  • Very low. Receptor occupancy occurs but downstream cAMP signalling is blocked at multiple points
  • Convenient but ineffective. No metabolic preparation required but efficacy severely compromised
  • Contraindicated. Post-meal administration wastes the dose. Sermorelin cannot overcome acute insulin and free fatty acid suppression. Clinical and research protocols universally avoid this timing.