Hexarelin vs Semax

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

HexarelinSemax
CategoryPeptidesPeptides
Standard DoseResearch indicates 100-200 mcg administered 1-2 times daily via subcutaneous injection.Research indicates 200-600 mcg daily via intranasal administration (0.1% solution, 2-3 drops per nostril).
TimingOn empty stomach, bedtime preferred. Avoid prolonged continuous use due to rapid desensitization.Morning and early afternoon dosing (avoid evening — may cause stimulation/insomnia). Intranasal preferred for rapid CNS delivery.
Cycle Duration4-8 week cycles maximum, then 4+ week break. Hexarelin desensitizes faster than other GHRPs.10-14 day cycles with equal rest periods. Some protocols use 3-5 day on / 2 day off patterns.
Evidence Levelmoderate_humanmoderate_human
A

Hexarelin

Peptides

Mechanism

Hexarelin (Examorelin) is a synthetic hexapeptide GHS-R1a agonist and the most potent synthetic GH secretagogue by peak GH release. It stimulates GH release through both pituitary ghrelin receptors and hypothalamic pathways, with mechanisms involving regulation of GHRH and somatostatin. Hexarelin also demonstrates significant cardiac benefits through activation of cardiac GHS-R1a receptors, protecting against ischemia-reperfusion injury and reducing cardiac fibrosis via the CD36 scavenger receptor pathway.

Standard Dosing

Research indicates 100-200 mcg administered 1-2 times daily via subcutaneous injection.

Timing

On empty stomach, bedtime preferred. Avoid prolonged continuous use due to rapid desensitization.

Cycle Duration

4-8 week cycles maximum, then 4+ week break. Hexarelin desensitizes faster than other GHRPs.

Side Effects

  • Significant cortisol elevation
  • Prolactin increase
  • Water retention
  • Joint pain
  • Rapid desensitization (unique to Hexarelin)

Contraindications

  • Active cancer
  • Cardiac arrhythmias (due to direct cardiac receptor activity)
  • Cushing's syndrome
  • Pregnancy and breastfeeding

Best Stacking Partners

CJC-1295 (no DAC)Sermorelin
B

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

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