Skin
,
N°
4
Few ingredients provoke as much enthusiasm — and as much damage — as retinol. Used wisely, it is transformative. Used carelessly, it is the most common cause of iatrogenic skin damage we see in our treatment room. Here is how to approach it properly.
What Retinol Actually Does
Retinol is a form of vitamin A. When applied topically, it is converted by skin enzymes first into retinaldehyde, then into retinoic acid — the biologically active form that binds to nuclear receptors and modulates gene expression. This sounds complex, but the outcomes are well-established: accelerated cell turnover, increased collagen synthesis, reduced hyperpigmentation, and improved skin texture over time.
The key phrase is over time. Retinol does not produce visible results in days or weeks. Meaningful change — the kind visible to others — typically requires three to six months of consistent use.
The Retinisation Period
The first four to six weeks of retinol use are characterised by purging, flaking, redness, and sensitivity. This is not an allergic reaction. It is retinisation — the skin's adjustment period as cell turnover accelerates. Most people abandon retinol during this window, convinced it is not working or is causing harm. In the majority of cases, it is working precisely as intended.
To navigate retinisation: start with the lowest available concentration (0.025% to 0.05%), apply every third night, and use it only over a completely dry face. A thin layer of plain moisturiser applied beforehand (the sandwich method) buffers the activity for those with more sensitive skin.
What to Avoid While Using Retinol
Acids and retinol should not share the same evening. Physical exfoliation is also contraindicated. And SPF in the morning becomes non-negotiable — retinol increases photosensitivity significantly, and UV exposure will counteract everything the retinol is working to achieve.
When to Stop
If the skin becomes persistently raw, weeping, or intensely reactive beyond week six, discontinue and allow the barrier to recover before reassessing. Retinol should challenge the skin gently, not overwhelm it.
— A NOTE IN THE MARGIN
"Retinol is not a trend. It is one of the most studied molecules in dermatology — and one of the most misused."
Notes & references
Note 1
Storage Matters
Retinol degrades in light and air. Always store it in opaque, airtight packaging. A product in a jar with a wide opening loses potency rapidly once opened — this is a formulation red flag, not a minor inconvenience.
Note 2
On dermal remodelling
Collagen synthesis, by contrast, is patient work — measured in months, not weeks. Most clinical endpoints in the literature land between week 12 and week 24 post-stimulus.
Note 3
A note on this piece
Written in the consultation room over four mornings. Edited with Helena Park. Errors are ours; the patience is the body's.
Speciality
— Ch. 05 · Continue reading
