The EYKOH Journal

Close-up of fingertips touching a small amount of white cream.
Retinoid Before or After Moisturizer? A Guide to Layering
The usual application order, when buffering may help and how to approach a cream that already contains a retinoid. Read more...
Two-panel photograph of a bracket fungus on a tree and dark conk pieces with orange interiors.
Reishi and Chaga Mushrooms in Skincare: What Research Shows
What extract studies and skin measurements reveal about mushroom ingredients, and where the evidence ends. Read more...
Person applying cream to the cheek beside a mirror in natural light.
How to Start Using a Retinoid With a Simple Routine
A practical beginner routine, with room for your skin to adjust and clear guidance on when to pause. Read more...
Pale cream swatch on a lightly textured neutral surface.
HPR Retinoid vs Retinol: What the Evidence Shows
A closer look at HPR, traditional retinol and the evidence that helps put ingredient claims in context. Read more...