The SPF Myths Dermatologists Would Like Retired
On the amount nobody applies, the difference between the two filter types, and whether you need it indoors.
The most evidence-backed ingredient in skincare, and the six weeks of misery most people put themselves through unnecessarily.
If you were allowed one active ingredient for the rest of your life, dermatologists would tell you to pick a retinoid and stop reading. The clinical evidence for photoageing, texture and acne is decades deep and unusually consistent.
The problem is almost never the molecule. It is the introduction.
Retinoids are a family of vitamin A derivatives that all convert, eventually, to retinoic acid — the only form the skin can use.
Retinyl esters are the weakest and require the most conversion steps. Retinol is the standard over-the-counter option. Retinaldehyde is one step closer and meaningfully stronger. Adapalene is available without prescription in many countries and is excellent for acne. Tretinoin is retinoic acid itself and requires a prescription.
“The differences between these are order-of-magnitude, not marginal,” says Priya Sandhu, PhD.
Twice a week for a fortnight. Three times a week for a fortnight. Alternate nights for a month. Then nightly if your skin is comfortable — and plenty of skin is not, which is fine.
A pea-sized amount for the entire face. More does not work faster; it works worse.
“There is no correlation between how much you peel and how much collagen you make.”Nora Kessler, MD
Apply moisturiser, then the retinoid, then moisturiser again. Buffering slows delivery and dramatically reduces irritation while retaining most of the effect.
Apply to completely dry skin — damp skin increases penetration and, with it, irritation. Wait ten minutes after cleansing.
The flaking, redness and stinging of the first weeks is barrier disruption, not evidence that it is working.
“There is no correlation between how much you peel and how much collagen you make,” says Dr Kessler. “If you are raw, you are not exfoliating faster — you are inflaming skin, and post-inflammatory pigmentation is a real risk, particularly in deeper skin tones.”
While you are adjusting, drop the acids, the scrubs and the vitamin C at the same time of day. Keep the routine to cleanser, retinoid, moisturiser.
And wear sunscreen every morning. Retinoids increase photosensitivity, and unprotected sun exposure undoes exactly the damage you are paying to repair. Stop entirely if you are pregnant or trying to conceive — oral retinoids are teratogenic and topical use is precautionarily advised against.
This article is general information reviewed for accuracy, not personal medical advice. Speak to a qualified clinician about your own health. WomenWelly is reader-supported and free to read; we buy the products we test.
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