Semax vs Sermorelin

Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.

SemaxSermorelin
CategoryPeptidesPeptides
Standard DoseResearch indicates 200-600 mcg daily via intranasal administration (0.1% solution, 2-3 drops per nostril).Research indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection.
TimingMorning and early afternoon dosing (avoid evening — may cause stimulation/insomnia). Intranasal preferred for rapid CNS delivery.Bedtime administration (aligns with natural nocturnal GH release). On empty stomach.
Cycle Duration10-14 day cycles with equal rest periods. Some protocols use 3-5 day on / 2 day off patterns.12-24 week cycles. Some protocols use continuous treatment.
Evidence Levelmoderate_humanstrong_human
A

Semax

Peptides

Mechanism

Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide analog of the ACTH(4-10) fragment that rapidly upregulates brain-derived neurotrophic factor (BDNF) and its signaling receptor TrkB in the hippocampus (1.4-fold BDNF protein increase, 3-fold exon III BDNF mRNA increase). It activates dopaminergic and serotonergic brain systems, enhances neurotrophin gene expression (BDNF, NGF), and modulates intracellular calcium dynamics in brain neurons. Semax lacks ACTH's corticotropic activity, acting purely as a nootropic/neuroprotective agent.

Standard Dosing

Research indicates 200-600 mcg daily via intranasal administration (0.1% solution, 2-3 drops per nostril).

Timing

Morning and early afternoon dosing (avoid evening — may cause stimulation/insomnia). Intranasal preferred for rapid CNS delivery.

Cycle Duration

10-14 day cycles with equal rest periods. Some protocols use 3-5 day on / 2 day off patterns.

Side Effects

  • Nasal irritation (intranasal route)
  • Mild headache
  • Stimulation/insomnia if dosed late
  • Irritability at high doses
  • Hair loss (anecdotal at high doses)

Contraindications

  • Seizure disorders
  • Acute psychosis or mania
  • Pregnancy and breastfeeding
  • Severe hypertension

Best Stacking Partners

SelankP21Noopept
B

Sermorelin

Peptides

Mechanism

Sermorelin is a synthetic 29-amino acid peptide representing the biologically active fragment of GHRH (amino acids 1-29) with full functional activity. It activates GHRH receptors on pituitary somatotrophs, stimulating cAMP production via Gs protein/adenylate cyclase and MAP kinase pathways. Due to the interactive effects of sermorelin and endogenous somatostatin, GH release is episodic rather than continuous. Sermorelin also stimulates pituitary gene transcription of GH mRNA, increasing and preserving pituitary GH reserve.

Standard Dosing

Research indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection.

Timing

Bedtime administration (aligns with natural nocturnal GH release). On empty stomach.

Cycle Duration

12-24 week cycles. Some protocols use continuous treatment.

Side Effects

  • Injection site reactions
  • Facial flushing
  • Headache
  • Dizziness
  • Transient taste changes

Contraindications

  • Active cancer
  • Pregnancy and breastfeeding
  • Intracranial hypertension

Best Stacking Partners

IpamorelinGHRP-2GHRP-6

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