Melanotan II vs Semax

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

Melanotan IISemax
CategoryPeptidesPeptides
Standard DoseResearch indicates 250-500 mcg daily via subcutaneous injection during loading, reducing to 250 mcg 2-3 times weekly for maintenance.Research indicates 200-600 mcg daily via intranasal administration (0.1% solution, 2-3 drops per nostril).
TimingAdminister 4-6 hours before UV exposure for optimal tanning synergy. Can be taken at any time of day.Morning and early afternoon dosing (avoid evening — may cause stimulation/insomnia). Intranasal preferred for rapid CNS delivery.
Cycle DurationLoading phase 1-2 weeks, then maintenance as long as desired. Pigmentation fades gradually upon discontinuation.10-14 day cycles with equal rest periods. Some protocols use 3-5 day on / 2 day off patterns.
Evidence Levelmoderate_humanmoderate_human
A

Melanotan II

Peptides

Mechanism

Melanotan II is a synthetic cyclic analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that non-selectively agonizes melanocortin receptors MC1, MC3, MC4, and MC5. MC1R activation stimulates eumelanin synthesis through tyrosinase upregulation, producing tanning. MC3R activation in the CNS increases libido and produces erectile responses. MC4R activation suppresses appetite. The cyclic structure provides enhanced in vivo stability (half-life 1-2 hours) and increased blood-brain barrier permeability compared to linear alpha-MSH.

Standard Dosing

Research indicates 250-500 mcg daily via subcutaneous injection during loading, reducing to 250 mcg 2-3 times weekly for maintenance.

Timing

Administer 4-6 hours before UV exposure for optimal tanning synergy. Can be taken at any time of day.

Cycle Duration

Loading phase 1-2 weeks, then maintenance as long as desired. Pigmentation fades gradually upon discontinuation.

Side Effects

  • Nausea (common, especially during loading)
  • Facial flushing
  • Spontaneous erections
  • Appetite suppression
  • Darkening of existing moles (monitor closely)
  • Fatigue
  • New nevus formation

Contraindications

  • History of melanoma or atypical moles
  • Active skin cancer
  • Pregnancy and breastfeeding
  • Addison's disease
  • Pheochromocytoma

Best Stacking Partners

PT-141
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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