Retinol and retinal are the two forms of vitamin A you can buy without a prescription, and the question of which one to use comes up in our Battersea clinic almost every week. Usually from someone who has tried retinol, been put off by the peeling, and wants to know whether the newer word on the label means anything or is just marketing.
It means something. The two molecules sit at different points on the same chain, and the difference explains most of what people experience: how quickly they see a change, how much their skin objects on the way there, and, on deeper skin tones, whether the objection leaves a mark. This article is our standing answer. It covers what the evidence actually shows, where to start on strength, who should not use vitamin A at all, and why we stock the retinal range we do. It is a clinical view, not a prescription, and it should be read alongside a skin assessment if you have a specific concern.
Retinol and retinal are both vitamin A. The difference is how many steps away they are.
Your skin does not use retinol directly. Every form of vitamin A you put on your face has to be converted, inside the skin cell, into retinoic acid, which is the form that binds to receptors in the cell nucleus and changes how the cell behaves. That is the same molecule as prescription tretinoin.
The chain runs in one direction. Retinol is converted to retinaldehyde, and retinaldehyde is converted to retinoic acid. Retinol therefore needs two conversions before it does anything. Retinal, which is simply the shorter name for retinaldehyde, needs one. Retinoic acid needs none, which is why it is the most effective and the most irritating, and why it is prescription-only. Sorg and colleagues at the University of Geneva, who did much of the original work on retinaldehyde in the 1990s, describe this as the reason retinaldehyde behaves more like retinoic acid in the skin while remaining a cosmetic ingredient (Sorg et al., 2006).
Each conversion step is done by enzymes, and the amount of enzyme in the skin is limited. That is the practical consequence: a proportion of the retinol you apply never becomes active, and the conversion is slow. Retinal skips the step that loses the most.
What the evidence shows, and what it does not.
The retinaldehyde evidence is older than most people assume. In 1994 Saurat and colleagues applied 0.05 percent retinaldehyde to human skin and showed that it produced the biological changes expected of a retinoid, including thickening of the epidermis, while being well tolerated (Saurat et al., 1994). Four years later Creidi and colleagues compared 0.05 percent retinaldehyde directly against 0.05 percent retinoic acid on photodamaged skin over 44 weeks, measuring the skin surface rather than asking people how they felt. Both improved wrinkle measurements, and retinaldehyde did so with better tolerance (Creidi et al., 1998). Fluhr and colleagues then tested retinol, retinaldehyde and retinoic acid under deliberately harsh conditions, applied under occlusion, and found retinaldehyde and retinol were both tolerated considerably better than retinoic acid (Fluhr et al., 1999).
Two later reviews put that work in context. Mukherjee and colleagues summarised the clinical evidence for retinoids in skin ageing and concluded that the cosmetic retinoids, retinol and retinaldehyde among them, are effective but need more time than tretinoin to show it (Mukherjee et al., 2006). Zasada and Budzisz reviewed the mechanism across the whole family and set out the conversion chain described above (Zasada and Budzisz, 2019).
What the evidence does not show is a large, modern, head-to-head trial of retinal against retinol at the strengths sold in shops, run for long enough to compare results rather than tolerance. That trial has not been done at the scale it deserves. So the honest claim is this: retinal reaches the active form more directly, the published studies show it matching prescription retinoic acid on measured change while being gentler, and retinol is a well-evidenced but slower route to the same place. Anyone telling you retinal is "eleven times faster" is quoting a laboratory figure, not a clinical one, and we do not use it.
| Form | Steps to retinoic acid | Typical strength | Where it sits |
|---|---|---|---|
| Retinol | Two | 0.2 to 1 percent in most products | Cosmetic. The most widely sold form. Slower to act, and the strength on the label overstates what reaches the receptor. |
| Retinal (retinaldehyde) | One | 0.05 to 0.1 percent | Cosmetic. Lower numbers on the label because less is lost in conversion. Naturally yellow, so it can mark pillowcases. |
| Retinoic acid (tretinoin), adapalene | None | 0.025 to 0.1 percent | Prescription-only medicines. Prescribed for conditions such as acne. Most effective, most irritating. |
Strength: where to start.
The mistake we see most often is not the wrong molecule. It is the right molecule, started too high and too often. Vitamin A causes a predictable adjustment period, sometimes called retinisation: dryness, fine flaking, a little warmth, occasionally a short crop of breakouts as the skin speeds up. That period is shorter and milder when the starting dose is low, and it is the period in which most people give up.
This is the introduction we ask people to follow, whichever product they use.
- Weeks one and two. Two nights a week, not consecutive. Cleanse, apply your usual moisturiser, wait a few minutes, then apply a pea-sized amount of the retinal over the top. Applying over moisturiser, sometimes called buffering, slows absorption and takes the edge off the first weeks without stopping the product working.
- Weeks three and four. Three nights a week if the skin is calm. Still over moisturiser.
- Week five onwards. Move towards nightly use if you want to and the skin allows. Many people stay at three or four nights a week indefinitely and get the full result. More is not better once the skin is responding.
- Every morning, throughout. Broad-spectrum SPF. Vitamin A makes the skin more sensitive to ultraviolet light while you are using it, and unprotected sun undoes the tone work it is doing.
Start with the lowest strength you can find, which for retinal usually means around 0.05 to 0.06 percent, and stay there for at least three months before considering a step up. If you have used retinol comfortably for a year, you can usually begin retinal at the same cadence you finished retinol on, but the first fortnight should still be buffered.
Deeper skin tones: irritation leaves a mark that outlasts the redness.
Everything above applies to every skin tone. This section is about why the introduction matters more on Fitzpatrick IV to VI, not about whether vitamin A belongs there. It does. Topical retinoids are one of the best-established treatments for acne and for the dark marks acne leaves behind in skin of colour, and the evidence for that is strong (Callender et al., 2022; DermNet, topical retinoids).
The catch is post-inflammatory hyperpigmentation. When skin with more active melanocytes is irritated, the inflammation itself can trigger a patch of darker pigment that stays for weeks or months after the redness has gone (DermNet, postinflammatory hyperpigmentation). On lighter skin a retinoid that is started too aggressively causes a few days of pink flaking and is forgotten. On deeper skin the same mistake can leave the very marks the person came to treat. Callender and colleagues reviewed this directly and reached the practical conclusion we work to: retinoids are appropriate and effective in skin of colour, but tolerability has to be actively managed, with lower starting concentrations, less frequent application and a moisturiser alongside (Callender et al., 2022).
In practice, for our Fitzpatrick IV to VI patients that means three things. Start on the lower-strength retinal, not the stronger one, regardless of how resilient the skin feels. Keep the buffered, two-nights-a-week phase for the full fortnight rather than shortening it. And treat the daily SPF as part of the treatment, because it is doing the job of protecting the tone work as much as the skin. The goal, as with everything we do for pigmentation, is even tone. It is never lighter skin.
Who should not use vitamin A, and when to pause it.
- Pregnancy, trying to conceive, and breastfeeding. Retinoids are avoided throughout. Oral retinoids cause birth defects, and although the amount absorbed from a cosmetic cream is very small, the NHS advises against topical retinoids in pregnancy and no cosmetic benefit justifies the question (NHS, acne treatment). Use a gentle cleanser, moisturiser and SPF, and come back to vitamin A afterwards.
- Prescription retinoids. If you are already on tretinoin, adapalene or isotretinoin, do not add a cosmetic retinal on top. Ask the clinician who prescribed it.
- Active eczema, rosacea flare or broken skin. Wait until the skin is settled. Vitamin A on a compromised barrier is how people end up with the irritation described above.
- Before and after in-clinic treatment. Our clinic protocol is to pause vitamin A for seven days before a chemical peel, microneedling or laser, and to restart only when we say the skin is ready, usually seven days after. Tell us what you are using at consultation and we will plan the dates.
- Strong sun without protection. Not a reason to avoid retinal, but a reason to be honest about whether you will wear SPF every day. If you will not, it is the wrong time to start.
What we stock, and why.
Melatone is an authorised UK stockist of ESK, an Australian range whose vitamin A products are all retinal rather than retinol. That was the reason we chose them. The formulation facts below are ESK's, from their own product information; the recommendation about who each one suits is ours, from using them in clinic.
The starting point
ESK Ultimate A
£77.00 50ml, around 3 to 4 months · £39.00 travel size 15ml
Retinal at 0.06 percent with niacinamide at 4 percent. This is where we start almost everyone who is new to vitamin A, and where we start every Fitzpatrick IV to VI patient regardless of experience. It is the gentlest of the three and it is enough for most people for a long time.
Pigmentation and renewal together
ESK Ultimate A Gold
£83.00 50ml, around 3 to 4 months · £42.00 travel size 15ml
Retinal at 0.1 percent with 4-n-butylresorcinol, a tyrosinase inhibitor, plus niacinamide and lactobionic acid. This is the night half of the pigmentation routine we recommend most often, paired with Enlighten Gold by day. It is the step up from Ultimate A once the skin has settled, not the place to start.
Texture and breakouts
ESK Ultimate A+
£83.00 50ml, around 3 to 4 months · £42.00 travel size 15ml
Retinal at 0.1 percent with glycolic acid at 2 percent. For resilient skin that is treating texture, congestion or the look of old scarring, and for people who have already tolerated a retinal well. Because it carries an exfoliating acid alongside the vitamin A, it is the one we are slowest to suggest for deeper skin tones and never the first retinal for anyone.
All three are night products. All three carry ESK's pregnancy warning. Free UK delivery on orders over £65, or £3.49 tracked below that, and the price you see is the price you pay.
Frequently asked questions
Is retinal better than retinol?
Retinal is one conversion step closer to retinoic acid, the form your skin actually uses, so it does the same job with fewer steps. In the published studies, retinaldehyde produced changes in photodamaged skin comparable to prescription retinoic acid while being better tolerated. Head-to-head trials of retinal against retinol at the strengths sold in shops are scarce, so the honest claim is that retinal reaches the active form more directly and tends to be gentler for the result it gives, not that it is better for everyone. The right choice depends on your skin, your history with vitamin A and what you are treating.
Can I use retinal every night?
Not at the start. We ask people to begin at two nights a week, applied over a moisturiser, for the first two weeks, then three nights a week for two weeks, and only then move towards nightly use if the skin is calm. Some skin never needs nightly use to get the result. Dryness, mild flaking and a little warmth in the first weeks are expected. Stinging, swelling, cracking or any new darkening are not, and mean stop and message us.
Can I use retinal with vitamin C?
Yes, but not in the same step. Vitamin C in the morning under SPF, retinal at night, is the routine we suggest. Do not layer retinal with exfoliating acids on the same night while you are building tolerance, because the combined irritation is what leaves marks, particularly on deeper skin tones.
Is retinal suitable for black or brown skin?
Topical retinoids are well established for acne and post-inflammatory hyperpigmentation in skin of colour, and retinal is suitable for all skin types, including Fitzpatrick V to VI. The difference is the introduction. On deeper skin tones the irritation from starting too high or too fast can itself leave dark marks that outlast the redness, so we start at the lower strength, on fewer nights, over a moisturiser, with daily SPF. Suitability is confirmed at consultation, not assumed from skin colour.
What are the UK rules on retinol strength?
In the European Union, Regulation 2024/996 caps retinol and its esters at 0.3 percent in face products, with no new non-compliant products placed on the market from November 2025. Great Britain keeps its own list of restricted cosmetic ingredients and, at the time of writing in September 2026, had not adopted the same cap. Retinal is a different molecule and is not the subject of that rule. Whatever the regulation, the strength that matters is the one your skin tolerates.
Retinal or a prescription retinoid?
Prescription retinoids such as tretinoin and adapalene are medicines, prescribed by a doctor, prescribing pharmacist or dermatologist for conditions such as acne. They are stronger and they are prescribed for a reason. Retinal is a cosmetic ingredient for people who want the renewal and tone benefits of vitamin A without a prescription. If you have active acne, a prescription route through your GP may be the right one and we will say so at consultation. We do not prescribe retinoids at Melatone.
References (Harvard)
- Saurat, J.H. et al. (1994) 'Topical retinaldehyde on human skin: biologic effects and tolerance', Journal of Investigative Dermatology, 103(6), pp. 770 to 774. PubMed: 7798613.
- Creidi, P. et al. (1998) 'Profilometric evaluation of photodamage after topical retinaldehyde and retinoic acid treatment', Journal of the American Academy of Dermatology, 39(6), pp. 960 to 965. PubMed: 9843009.
- Fluhr, J.W. et al. (1999) 'Tolerance profile of retinol, retinaldehyde and retinoic acid under maximized and long-term clinical conditions', Dermatology, 199 (Suppl. 1), pp. 57 to 60. PubMed: 10473963.
- Sorg, O., Antille, C., Kaya, G. and Saurat, J.H. (2006) 'Retinoids in cosmeceuticals', Dermatologic Therapy, 19(5), pp. 289 to 296. PubMed: 17014484.
- Mukherjee, S. et al. (2006) 'Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety', Clinical Interventions in Aging, 1(4), pp. 327 to 348. PubMed: 18046911.
- Zasada, M. and Budzisz, E. (2019) 'Retinoids: active molecules influencing skin structure formation in cosmetic and dermatological treatments', Postepy Dermatologii i Alergologii, 36(4), pp. 392 to 397. PubMed: 31616211.
- Callender, V.D. et al. (2022) 'Effects of topical retinoids on acne and post-inflammatory hyperpigmentation in patients with skin of color: a clinical review and implications for practice', American Journal of Clinical Dermatology, 23(1), pp. 69 to 81. PubMed: 34751927.
- DermNet (n.d.) Topical retinoids. Available at: dermnetnz.org/topics/topical-retinoids.
- DermNet (n.d.) Postinflammatory hyperpigmentation. Available at: dermnetnz.org/topics/postinflammatory-hyperpigmentation.
- NHS (n.d.) Acne: treatment. Available at: nhs.uk/conditions/acne/treatment.