The muscles surrounding the knee joint include the tensor fasciae latae, sartorius, quadriceps femoris, vastus intermedius, vastus medialis, vastus lateralis, semitendinosus, semimembranosus, biceps femoris, and gracilis
Perhaps most significantly, GHK-Cu amplifies hair follicle stem cells
Two to three resistance sessions weekly (full body, 30 to 45 minutes) preserves muscle, supports metabolism, and improves long-term outcomes
Why they work together: Stimulates Type I, III, and IV collagen Enhances retinol's anti-aging effects Minimal irritation risk Supports skin barrier function Application strategy: Layer together in same routine (peptide first) OR separate AM/PM Signal peptides vs neurotransmitter peptides with retinol Signal peptides (like Matrixyl, Syn-Coll): Best compatibility with retinol Work synergistically Can apply together or separately Neurotransmitter peptides (like Argireline, Leuphasyl): Good compatibility but better separated Different pH requirements may interfere Apply separately (AM vs PM) for best results Peptides to avoid combining with retinol AHA/BHA peptide combinations: Products that combine peptides with acids (glycolic, salicylic) Adding retinol on top = potential over-exfoliation Use peptide+acid products separately from retinol nights High-dose vitamin C + peptides + retinol: All three together may be too much for sensitive skin Vitamin C (L-ascorbic acid) can destabilize retinol Better to separate: Vitamin C AM, Peptides + Retinol PM See our glow peptides guide for complete skincare peptide protocols
