Retinol: A GP’s Honest Guide to Using It Properly
The daytime mistake that wastes it, how to start without wrecking your barrier, and why not all retinols are equal.
By Dr Amber Halliday, MRCGP MBBS BSc (Hons) — GP & Aesthetics Doctor | Blue Bird Aesthetics, Worthing | Updated 2026
Retinol is the most evidence-backed anti-ageing ingredient there is — and the one I see misused most. Used well, it is transformative. Used badly, it irritates your skin and damages your barrier while delivering almost none of the benefit. The difference is all in how you use it.
Retinol works while you sleep. Used in daylight, it mostly just irritates — you get the downside and almost none of the reward.
— Dr Amber Halliday
Who This Guide Is For
- Anyone curious about retinol but worried about irritation.
- People who have tried retinol and given up.
- Anyone confused by the huge range of products and strengths.
- Those wanting a doctor-led, low-and-slow approach.
TL;DR — Key Takeaways
Short on time? Here’s the summary:
✓ Retinol speeds skin turnover and stimulates collagen, doing its repair work overnight.
✓ Using it in the daytime is the most common mistake — UV degrades it and you just irritate the skin.
✓ Start low and slow: once or twice a week, building up gradually.
✓ Emerging evidence favours a low dose every night over a high dose now and then.
✓ Not all retinols are equal — strength, formulation and guidance matter.
✓ It should be paused in pregnancy and breastfeeding.
1. What retinol really does
Retinol is a form of vitamin A. It speeds up how quickly your skin renews itself and stimulates collagen in the deeper layers, which over time improves texture, tone, fine lines and overall skin quality. Importantly, it does this repair work overnight — which is the key to using it properly.
2. The most common mistake: using it in the day
Far too many people apply retinol in the morning. UV light degrades it, so it no longer does its job, and all you are left with is irritation of the upper layers of skin and a weakened barrier — the downside with none of the benefit.
The simplest rule
Retinol is a night-time product. Apply it in the evening, let it work while you sleep, and protect with SPF in the day.
3. How to start without wrecking your barrier
Low and slow is the whole secret. You might use it once or twice a week for the first month, then build up to three times a week, and only later consider increasing the strength if you need to. Rushing it is what causes the flaking, redness and barrier damage that make people give up.
4. Low dose nightly, or high dose occasionally?
The evidence increasingly favours a low dose every night over a high dose once or twice a week. A gentle, consistent amount tends to give better long-term results, with far less of the irritation that comes from intermittent high-strength use.
5. The biggest myth: that they are all equal
They are not. Retinol commonly triggers an adjustment reaction in the skin, and going through that with a clinician who can guide you, manage your expectations and support your barrier gets you faster, deeper, longer-lasting results — rather than working your way through a shelf of underpowered products and hundreds of steps before you ever reach an effective dose. My honest view on the wider topic is in is medical-grade skincare worth it?.
6. Who should pause or take care
Take advice, or pause, if:
- You are pregnant or breastfeeding — retinoids should be stopped.
- Your skin is very reactive or your barrier is already compromised — start gentler and slower.
- You are having in-clinic treatments — we may pause retinol around them.
- You are using other strong actives — introduce one thing at a time.
Retinol is the best-evidenced anti-ageing ingredient we have. The trick is not strength — it is consistency, patience and a little guidance.
— Dr Amber Halliday
Frequently Asked Questions
Should I use retinol in the morning or at night?
At night. UV degrades retinol, so daytime use mostly just irritates the skin. Apply in the evening and use SPF during the day.
How often should I start using it?
Low and slow — once or twice a week for the first month, building to three times a week, then increasing strength only if needed.
Why is my skin peeling or irritated on retinol?
Usually because it has been started too strong or too fast. Ease back, support the barrier with moisturiser, and build up more gradually.
Can I use retinol with vitamin C or acids?
With care. It is often best to alternate them and introduce one active at a time, rather than layering everything at once.
Can I use retinol in pregnancy?
No. Retinoids should be paused during pregnancy and breastfeeding — we would use gentler alternatives in the meantime.
Will retinol thin my skin?
No — that is a myth. Over time it thickens the deeper, living layers of skin while improving the surface.
How long until I see results?
Give it several weeks to a few months of consistent night-time use. Skin renewal is gradual.
Is a prescription-strength retinoid better than an over-the-counter one?
Not all retinols are equal. A guided, well-formulated retinoid usually outperforms a shelf of underpowered products — strength and formulation matter.
Can I use retinol in summer?
Yes, at night, as long as you are diligent with daily SPF — which you should be anyway.
The Takeaway
Retinol earns its reputation — but only when it is used at night, started gently, and kept consistent. The people who succeed with it are not the ones who go hardest; they are the ones who go slowly and stick with it.
If you have tried it and given up, the odds are it was started too strong or used at the wrong time of day. With a little guidance, it is one of the best things you can do for your skin.
If you would like a routine built around retinol that suits your skin, a consultation is the place to start.
Ready to talk it through?
Book a calm, considered, commitment-free consultation in Worthing.
We’ll build a retinol routine matched to your skin and your tolerance — gently, and with no pressure to buy.
