4COMPLEXION's Substack

Does Your Skin Really "Absorb Everything"?

A cosmetic chemist on how little your skincare actually gets past the surface. Clean beauty, wellness, and whether a sunscreen causes cancer.

Jun 6 • Marina | 4COMPLEXION

27

7

2

May 2026

I'm a cosmetic chemist. Stop blaming 'pore-clogging' ingredients. Here's what really clogs skin, and how to clear it.

A biochemist's look at what really triggers clogged pores: sebum, dead skin, and formula behaviour, plus the evidence-based routine that keeps them…

May 31 • Marina | 4COMPLEXION

264

23

17

No, Tretinoin Isn't Killing People. Reading the Papers.

A close look at the claim that tretinoin causes deaths, thins your skin, lets pollutants into your bloodstream, and is the same compound used in…

May 23 • Marina | 4COMPLEXION

12

3

5

"Anti-ageing" creams won't fix menopausal skin. Here's what actually does.

A cosmetic chemist/biochemist's deep dive into the molecular biology of menopausal skin, the topical oestrogen evidence, and the protocol that actually…

May 19 • Marina | 4COMPLEXION

340

41

31

April 2026

Your "dark spot" serum won't fix those red marks. Here's what will.

A cosmetic chemist explains why post-acne red/purple marks are a blood vessel problem, not a pigment problem, and what actually fades them.

Apr 14 • Marina | 4COMPLEXION

29

6

2

Your melasma serum isn't working. Here's why.

A cosmetic chemist breaks down the ingredients that work, the ones that don't, and why melasma needs a protocol — not a miracle serum.

Apr 10 • Marina | 4COMPLEXION

22

1

2

March 2026

When the Formula Becomes a Prop: A Cosmetic Chemist on What the Texture Trend Is Actually Costing Us

A professional opinion piece

Mar 29 • Marina | 4COMPLEXION

26

4

5

Fungal Acne: Everything You Need to Know (Backed by Science, Explained Like a Friend)

Written from the perspective of a cosmetic chemist and biochemist with links to every study so you can check the receipts.

Mar 16 • Marina | 4COMPLEXION

13

2

3

February 2026

How to Tell Whether a Peptide Serum Will Actually Work

A cosmetic chemist's guide to the science of penetration, concentration, and formulation - everything brands don't tell you, decoded.

Feb 24 • Marina | 4COMPLEXION

23

7

2

How to Heal Your Damaged Skin Barrier While Managing Acne: A Science-Based Guide

The barrier-acne cycle: why your skin stays inflammed, and the evidence-based way out.

Feb 15 • Marina | 4COMPLEXION

27

17

4

The Whole Truth About Milky Toners.

What milky toner actually does, who's most likely to benefit (or skip it), whether it really messes with serum absorption, and how to skim an INCI list…

Feb 8 • Marina | 4COMPLEXION

17

15

1

What's best: Tretinoin 4x/week or Retinal Daily?

This is among the most asked questions. Let's explore the current evidence and see if we can hopefully find the answer.

Feb 2 • Marina | 4COMPLEXION

17

2