Send a text

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:

Meder by Dr. Tiina Meder

Meder Beauty Instagram

Meder Beauty Facebook

Meder Beauty TikTok

Meder Beauty LinkedIn

Meder Beauty YouTube

Listen to the Meder Beauty Podcast on Apple Podcasts