Ingredient or product comparison
Temporal Profiles: Semax Delayed Neurotrophic vs GHK-Cu Biphasic Antioxidant
The temporal dynamics of neuroprotection differ critically between the two compounds — a difference with direct implications for post-injury intervention timing: Semax temporal profile: MC4R binding → cAMP → CREB-pSer133 (30 minutes) → BDNF mRNA (1–2 hours) →
This source-based comparison does not add ratings or recommend a winner.
- The temporal dynamics of neuroprotection differ critically between the two compounds — a difference with direct implications for post-injury intervention timing:
- Semax temporal profile: MC4R binding → cAMP → CREB-pSer133 (30 minutes) → BDNF mRNA (1–2 hours) → BDNF protein (6–12 hours) → TrkB-PI3K-Akt-Bcl-2 anti-apoptotic signalling (12–24 hours) → neuroprotective plateau (24–72 hours with continued dosing). Optimal intervention window: within 3–6 hours of injury onset for ischaemia models; within 1–2 hours for excitotoxicity. Delayed administration (>12 hours post-injury) still provides benefit via post-injury trophic support but misses the acute anti-apoptotic window.
- GHK-Cu temporal profile: Phase 1 (immediate, 0–30 min): extracellular metal chelation → reduced Fenton radical generation → physicochemical ROS reduction. Phase 2 (rapid, 2–4 hours): Keap1 oxidation → Nrf2 nuclear translocation → ARE-driven gene induction → HO-1 protein (4–8 hours) → broad antioxidant defence establishment. Phase 3 (sustained, 24–72 hours): NF-κB suppression via IκBα stabilisation → reduced IL-6, TNF-α, IL-1β → anti-inflammatory neuroprotection. GHK-Cu is effective across all three phases and retains efficacy when administered up to 6 hours post-injury — later than most antioxidant interventions due to its dual physicochemical + transcriptional mechanism.