Archive for April 2026
April 22nd, 2026 by Dr. Hannah Sivak
May I offer a definition? “A substance that, applied topically, will help reverse the manifestations of skin aging, including the capacity to prevent the entry of noxious chemicals and microbes, loss of elasticity, impaired pigmentation, wrinkles, increased itching or pain, etc.” This definition contradicts the FDA’s “rule” that cosmetics shouldn’t alter skin physiology but can change skin appearance. But of course, anti-aging cosmetics change skin physiology (and appearance), even if we insist on pretending otherwise to keep the FDA happy. In my book and in my pamphlet “Chemicals that Nature Makes,” I mention some anti-aging ingredients. For some of them, there is strong experimental evidence from scientific journal articles. Still,…
April 14th, 2026 by Dr. Hannah Sivak
At Imperial College London, Claire Higgins, a professor of bioengineering , and her collaborators, performed a pilot clinical study in which they transplanted hair follicles into human skin scars. The transplanted hair follicles helped remodel the scarred skin to create functional tissue. Follicle transplantation may become a clinically approved treatment to reduce scar formation and remodel preexisting scar tissue. How about adding the healing power of keratinocyte growth factor (KGF) into the mix? Reference Plotczyk, M., Jiménez, F., Limbu, S. et al. Anagen hair follicles transplanted into mature human scars remodel fibrotic tissue. npj Regen Med 8, 1 (2023). https://doi.org/10.1038/s41536-022-00270-3
April 8th, 2026 by Dr. Hannah Sivak
Below, I describe the properties of some natural chemicals that are used in skin care. If you would like to know about a chemical that is not in this list, let me know, and I will add it in subsequent “editions”. Natural chemicals are those present in nature, in plants and/or animals. The actual ingredient you find in a formulation may be obtained by chemical synthesis, fermentation, or biotechnology; what matters to your body is the chemical structure, not the “origin”. Chemical structure is not just the number of atoms and how they are linked to each other, but also how they are organized in space. I included some references…