Signal peptides, carrier peptides, neurotransmitter peptides—what does the clinical evidence actually say?
Peptides are short chains of amino acids—the building blocks of proteins like collagen and elastin. In skincare, they act as messengers, signaling your skin to perform specific functions like producing more collagen or relaxing muscles.
The big question: Can topical peptides actually penetrate skin and trigger these effects?
✓
Some peptides work
Good evidence exists
~
Many are unproven
Limited/no clinical data
✗
Not a retinoid replacement
Different mechanism
These "tell" skin cells to produce more collagen, elastin, or other matrix proteins. They mimic the fragments released when collagen breaks down, tricking skin into thinking it needs repair.
Evidence: Good
Multiple studies show wrinkle reduction. One of the most researched peptides.
Evidence: Good
Combination of palmitoyl tripeptide-1 and tetrapeptide-7. Targets collagen + inflammation.
These deliver trace minerals (like copper) to skin cells, which are needed for various enzymatic processes including wound healing and collagen synthesis.
Evidence: Good
Promotes wound healing, collagen synthesis, has antioxidant effects. One of the best-researched peptides. Note: can cause purging initially.
Often marketed as "topical Botox," these aim to reduce muscle contractions that cause expression lines. The million-dollar question: can they actually reach muscle tissue?
Evidence: Mixed
Some studies show modest reduction in fine lines. Results far less dramatic than Botox. May work better in eye area where skin is thinner.
Evidence: Limited
Extended version of Argireline. Mostly manufacturer-funded studies. More research needed.
Here's the uncomfortable truth: many peptides are too large to effectively penetrate the skin barrier. The 500 Dalton rule suggests molecules over 500 Da have difficulty penetrating—and many peptides exceed this.
Provide modest anti-aging benefits, support skin repair, complement your routine, be gentler than retinoids
Replace retinoids or Botox, provide dramatic results, work overnight, penetrate as well as smaller molecules
Disclaimer: This article is for educational purposes only and is not intended as medical advice. The information presented is based on generally accepted skincare science, but individual results may vary. Always consult a board-certified dermatologist or healthcare provider before making changes to your skincare routine, especially if you have existing skin conditions.
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