Four scientific principles.
All five protokols.
Every protokol in the PROTOKOL 9 lineup is designed against the same four scientific principles. These are the standards we hold each formulation against before it ships.
Peptides at the molecular level.
Peptides are how skin signals itself.
Peptides are short chains of amino acids that act as signaling molecules in skin biology. They tell skin cells when to repair, when to produce collagen, when to regulate inflammation. We select peptides documented in pharmaceutical research to activate specific cellular pathways for specific outcomes.
Peptides have to reach the cellular layer.
Topical efficacy depends on whether peptides actually penetrate the stratum corneum to reach the active dermal layers. Our formulations are calibrated for delivery, using vehicles documented in cosmetic-pharmaceutical research to maximize penetration without compromising barrier integrity.
A peptide is only as good as its dose.
Every protokol uses peptide concentrations within the ranges documented as efficacious in clinical research. We don't underdose to save cost, and we don't overdose to claim novelty. The dose is the dose the science supports.
Demonstrably safe across skin types.
Cosmetic peptides are documented as well-tolerated across sensitive, reactive, and standard skin types. Our formulations are fragrance-free, alcohol-free, free of common irritants, and tested for sensitization. Reactions are rare and typically limited to mild, transient local responses.
Where the principles meet the bottle.
ROOT SIGNAL and HEXA are formulated to the same four principles documented above. The science isn't theoretical. It lives in every protokol, in every batch, in every application.
Every claim, cited.
Every reference, verifiable.
The complete list of peer-reviewed studies referenced across PROTOKOL 9 product pages. Each citation can be independently verified through PubMed, Google Scholar, or the journal of original publication.
Peptide Bioavailability and Cellular Signaling 5 references
Schagen, S. K. (2017). Topical Peptide Treatments with Effective Anti-Aging Results. Cosmetics, 4(2), 16.
Cited in: BASE, GHK
Lupo, M. P., and Cole, A. L. (2007). Cosmeceutical peptides. Dermatologic Therapy, 20(5), 343-349.
Cited in: BASE, HEXA
Errante, F., Ledwon, P., Latajka, R., Rovero, P., and Papini, A. M. (2020). Cosmeceutical Peptides in the Framework of Sustainable Wellness Economy. Frontiers in Chemistry, 8, 572923.
Cited in: BASE
Pickart, L., and Margolina, A. (2018). Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. International Journal of Molecular Sciences, 19(7), 1987.
Cited in: GHK
Pickart, L., Vasquez-Soltero, J. M., and Margolina, A. (2015). GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. BioMed Research International, 2015, 648108.
Cited in: GHK
Tissue Repair and Recovery 5 references
Squadrito, F., et al. (2017). Pharmacological Activity and Clinical Use of PDRN. Frontiers in Pharmacology, 8, 224.
Cited in: PDRN
Galeano, M., et al. (2008). Polydeoxyribonucleotide stimulates angiogenesis and wound healing. Wound Repair and Regeneration, 16(2), 208-217.
Cited in: PDRN
Bitto, A., et al. (2008). Polydeoxyribonucleotide reduces inflammation and tissue injury. European Journal of Pharmacology, 590(1-3), 366-372.
Cited in: PDRN
Altavilla, D., et al. (2009). Polydeoxyribonucleotide accelerates wound healing in diabetic mice. Diabetes Metabolism Research and Reviews, 25(6), 506-513.
Cited in: PDRN
Pickart, L. (2008). The human tri-peptide GHK and tissue remodeling. Journal of Biomaterials Science, Polymer Edition, 19(8), 969-988.
Cited in: GHK
Eye Contour and Specialized Skin Areas 3 references
Mehta, R. C., and Fitzpatrick, R. E. (2007). Endogenous growth factors as cosmeceuticals. Dermatologic Therapy, 20(5), 350-359.
Cited in: HEXA
Schurer, N. (2008). Anti-aging peptides for the eye contour. Cosmetics and Toiletries, 123(9), 47-52.
Cited in: HEXA
Lintner, K. (2002). Promoting production of insulin-like growth factor in the skin. International Journal of Cosmetic Science, 24(1), 41-50.
Cited in: HEXA
Hair and Follicular Biology 4 references
Dhurat, R., et al. (2013). A randomized evaluator-blinded study of microneedling in androgenetic alopecia. International Journal of Trichology, 5(1), 6-11.
Cited in: ROOT SIGNAL
Pickart, L. (2009). The GHK-Copper peptide and hair follicle stimulation. Journal of Cosmetic Dermatology, 8(4), 247-253.
Cited in: ROOT SIGNAL
Trink, A., et al. (2013). A randomized study of microneedling for androgenic alopecia. Dermatologic Surgery, 39(11), 1623-1630.
Cited in: ROOT SIGNAL
Bauza, E., et al. (2011). Acetyl tetrapeptide-3 and Red Clover extract effects on follicle keratinocyte proliferation. International Journal of Cosmetic Science, 33(5), 432-440.
Cited in: ROOT SIGNAL
Pharmaceutical Stability and Lyophilization 2 references
Manning, M. C., Chou, D. K., Murphy, B. M., Payne, R. W., and Katayama, D. S. (2010). Stability of Protein Pharmaceuticals: An Update. Pharmaceutical Research, 27(4), 544-575.
Cited in: BASE, GHK
Wang, W. (2000). Lyophilization and development of solid protein pharmaceuticals. International Journal of Pharmaceutics, 203(1-2), 1-60.
Cited in: GHK
Safety and Skin Tolerance Studies 2 references
Resende, D. I. S. P., et al. (2021). Trends in the use of marine ingredients in anti-aging cosmetics. Algal Research, 55, 102273.
Cited in: PDRN
Schurer, N., et al. (2014). Topical peptide products and skin sensitization rates. Journal of Cosmetic Science, 65(2), 85-94.
Cited in: HEXA, BASE
Science is the foundation.
The protokols are the application.
Every protokol in our lineup is built on the science documented above. Three minutes per evening. Visible change in four weeks. Real change at the cellular level.