Meder Beauty
You want healthy, glowing skin—but with all the products, trends, and conflicting advice, it’s hard to know what actually works. Welcome to the Meder Beauty Podcast, hosted by Dr. Tiina Meder, a former cardiologist and board-certified dermatologist. In each episode, we uncover what really matters, break down the science, and give you real, expert-backed skincare advice. Whether you’re looking to achieve radiant healthy skin, curious about anti-aging, or want to understand what’s really in your products, you’re in the right place. Rooted in science and the truth about what your skin actually needs, we’ll have in-depth conversations with leading dermatologists, medical experts, and skincare brand founders to bring you the latest innovations, evidence-based insights, and industry secrets that truly make a difference.
Meder Beauty
The Truth About Skin Absorption and Safety
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Do creams really penetrate the skin? And if they do, how deep and how safely?
On the Meder Beauty Podcast, I explain how skincare actually moves through the skin barrier and why penetration is not simply a marketing promise, but a scientific and safety question. I break down the 500 Dalton rule, which ingredients can truly pass through the stratum corneum, and why size, location, and even time of day influence absorption.
I talk about peptides, retinol, niacinamide, acids, and the surprising role of water as one of the strongest penetration enhancers. I also explain why over-exfoliation, microneedling, and barrier damage can increase permeability, sometimes in ways that are not beneficial. Penetration should be selective, smart, and controlled. In this conversation, I’ll help you understand what really reaches your skin and what should not.
Episode resources:
The 500 Dalton rule for the skin penetration of chemical compounds and drugs
Learn more from the previous episodes:
Your Skin’s Hidden Ecosystem: Why the Microbiome Matters More Than You Think
The Magic of Peptides: Why They’re Transforming Skincare Forever
Beyond Retinol: The New Science of Safer, Smarter Skincare
Understanding Acne: Myths vs. Science
Connect with us:
Listen to the Meder Beauty Podcast on Apple Podcasts