What Is Retinol and What Does It Do for Your Skin?

Retinol works because, after being applied to the skin, it is converted into retinoic acid — the active form of vitamin A — which binds to receptors inside cells and changes the expression of genes involved in cell renewal and collagen production. That is why, after a few weeks, texture improves, fine lines soften and tone becomes more even. But there are clear limits: it is not immediate, it does not erase deep wrinkles and it does not replace sun protection.

In this article we explain what happens in the skin when you apply retinol, what the clinical evidence shows, who benefits most, how to use it without irritation and why vitamin A in gummies is not the same thing as topical retinol.

What happens in your skin when you apply retinol

Retinol is a derivative of vitamin A. When applied topically, it is converted in the skin into retinoic acid, which binds to nuclear receptors (retinoic acid receptors and retinoid X receptors) and regulates the expression of genes linked to skin cell growth and differentiation ¹. Vitamin A is essential for cell differentiation, regulation of epidermal cell growth and normal skin maintenance ².

In practice, this translates into three main effects:

• Faster cell renewal: old, pigmented cells on the surface are replaced more quickly, which improves texture and tone.
• More collagen: topical retinoids can soften photoageing and contribute to thickening and restoring skin collagen ³.
• Less hyperpigmentation: accelerated renewal helps reduce spots, although this effect is better studied with prescription retinoids.

Note that retinol is only one of the retinoids: there are natural and synthetic retinoids, with different routes of administration, doses and safety profiles, recommended for different situations ³. Over-the-counter retinol is the gentlest — and the slowest.

Does retinol really work? What the evidence shows

Yes, it works — but with important caveats. In a randomised, double-blind, vehicle-controlled trial, 36 elderly people (mean age 87 years) applied 0.4% retinol lotion or the vehicle up to three times a week for 24 weeks. At the end, retinol-treated skin showed significant improvement in fine wrinkles compared with skin treated with the vehicle alone, and biopsies showed increased expression of glycosaminoglycans and procollagen I ⁴.

It is a small study in a very elderly population — which means the results do not automatically generalise to everyone or to all concentrations. In addition, much of the clinical evidence on retinoids uses retinoic acid or other prescription retinoids, which are more potent than over-the-counter retinol ³. Retinol needs to be converted in the skin, and that conversion is inefficient: only a fraction of the amount applied reaches the active form.

That is why results take time. Expect visible improvements only after 8 to 12 weeks of consistent use, and maximum effects after several months. Consistency is the factor that matters most.

What retinol does not do

There is a lot of exaggerated information about retinol. To avoid wrong expectations:

• It is not a DIY Botox: it does not paralyse muscles or erase expression lines.
• It does not remove deep wrinkles or replace collagen lost in excess.
• It does not treat deep acne scars.
• It does not give immediate results: anyone promising effects in days is exaggerating.
• It does not replace sun protection. On the contrary: retinol makes skin more sensitive to the sun, so sunscreen in the morning is essential.

It is also not true that "the stronger, the better". Higher concentrations cause more irritation without additional benefit for most people. And retinol does not thin the skin as a whole: the surface layer becomes thinner, but the deeper layers become thicker ³.

Who retinol is really useful for — and who it is not

Topical retinol is most useful for people with oily skin, a tendency to acne, sun spots or fine lines. On very sensitive skin, rosacea or active dermatitis, it can irritate and worsen the condition — in that case, talk to a dermatologist before trying it.

If you are under 25 and do not have acne, retinol is not necessary. Collagen production is still high and early use does not stop ageing. What helps is sun protection, starting now.

In any case, pregnancy, breastfeeding, active skin disease or taking medication require advice from a healthcare professional before starting retinoids.

How to use retinol without damaging your skin

The golden rule is to start slowly:

1. Start with a low concentration (0.1% to 0.3%) and apply only two to three times a week, at night.
2. Use a small amount — pea-sized — on clean, dry skin.
3. Avoid the eye and lip area, where the skin is thinner.
4. If it irritates, reduce the frequency or apply a moisturiser on top (the "sandwich" technique).
5. After a month, if you tolerate it well, you can gradually increase to three nights a week.
6. Sunscreen in the morning, every day, even in winter.

Do not combine retinol with other strong actives on the same night, such as glycolic acid or benzoyl peroxide. If you use any of them, alternate nights.

Topical retinol vs. vitamin A in gummies: are they the same thing?

No. What works on the skin when applied topically is not equivalent to what works when ingested. Oral vitamin A is essential for internal functions — vision, immunity, reproduction, cell differentiation — and only a small part reaches the skin ⁵. The evidence that taking vitamin A supplements improves the appearance of the skin is much weaker than the evidence for topical retinol.

In addition, vitamin A is fat-soluble and accumulates in the body; excess can be toxic, especially in people with cystic fibrosis, in whom excessive levels can harm the respiratory and skeletal systems ⁶. Do not take vitamin A supplements without a real need and always check the label.

The maximum daily intake of preformed vitamin A (retinol) established by EFSA for adults is 3,000 µg per day ⁷. This value applies to total intake — food and supplements — and is especially relevant for those who already consume liver, eggs, dairy and other foods rich in vitamin A.

Hair & Nails Gummies provide 630 µg of vitamin A (79% of the NRV) per 2-gummy serving. This is a food supplement dose, not a dermatological treatment dose, and does not replace topical retinol. For the skin, the route with the most evidence remains topical application.

What a vitamin A supplement label tells you

When a supplement includes vitamin A, the label must state the amount per serving and the percentage of the NRV (nutrient reference value). In the case of Hair & Nails Gummies, each 2-gummy serving provides 630 µg of vitamin A, which corresponds to 79% of the NRV. The directions for use are to chew 2 gummies per day, preferably after a meal, and not to exceed the recommended daily dose.

The label warnings are important: in case of pregnancy, breastfeeding, illness or taking medication, you should consult a healthcare professional before use. The product contains polyols and excessive consumption may have a laxative effect. Biotin, present in the formula, may interfere with the results of some laboratory tests — before having tests, inform your doctor and the laboratory that you take this supplement.

To better understand how to interpret vitamin A doses and labels, see the guide Retinol: recommended daily dose and how to read labels.

Retinol and the sun: why sun protection is essential

Vitamin A has a complex photobiology. Laboratory studies show that exposure of retinol or its esters to ultraviolet light generates reactive species, such as singlet oxygen and superoxide anion, which can damage lipids and DNA; retinyl palmitate has been shown to be photomutagenic in in vitro test systems ².

These results come from in vitro mechanistic studies and do not prove that topical retinol causes damage to human skin under real conditions of use. But they reinforce a universal practical recommendation: anyone using retinol should use sunscreen in the morning, every day, and avoid intense sun exposure without protection.

Limitations and when to talk to a professional

The evidence on topical retinol has limitations: studies are relatively small, often in specific populations (such as institutionalised elderly people ⁴), and much of the clinical data refers to prescription retinoids, not over-the-counter retinol ³. This means that promises of rapid or universal results are not supported by the available evidence.

Talk to a dermatologist or healthcare professional if: you have very sensitive skin, rosacea or active dermatitis; you are pregnant or breastfeeding; you are taking other topical or oral medicines; or if irritation persists despite reducing frequency. In children, do not use topical retinol without medical advice — and never give vitamin A supplement doses to children without professional advice.

If you have questions about the safety of vitamin A in children, see the guide Retinol for children: is it safe? What to know. To understand when to apply topical retinol — morning or night — see Retinol: when to take it? The best time, morning or night.

If your goal is to support overall skin health from within, you can explore our Beauty range or the guides on collagen, which have their own evidence — different from that of topical retinol.

The honest verdict

Retinol is one of the few substances with solid science behind it, but it is not magic. It works for fine lines, acne and spots, provided you use it regularly and patiently, and provided you protect your skin from the sun. It does not work for deep wrinkles, does not give immediate results and is not for everyone. If you have sensitive skin, see a dermatologist. If you just want to look after your skin as it ages, use sunscreen. And if you decide to try it, start slowly, with a low concentration, and give your skin time to adapt.

Frequently asked questions

Does retinol really work for fine lines?

Yes, there is evidence that topical retinol improves fine lines associated with natural ageing. In a randomised, vehicle-controlled trial, 36 elderly people applied 0.4% retinol up to three times a week for 24 weeks and the treated skin showed significant improvement in fine lines. Results take weeks to appear and do not automatically generalise to all concentrations or skin types.

How long does retinol take to work?

The first signs usually appear after 8 to 12 weeks of consistent use, with maximum effects after several months. Retinol needs to be converted in the skin into retinoic acid, and this conversion is inefficient, which explains the slowness. If you stop for weeks, the skin tends to return to its previous state.

Can I use retinol every day?

It is not recommended to start that way. The usual approach is to start with a low concentration, two to three times a week at night, and increase gradually as tolerated. Applying it every day from the start increases the risk of redness, peeling and stinging. If the skin becomes irritated, reduce the frequency or apply a moisturiser on top.

Do retinol gummies have the same effect as topical retinol?

No. Topical retinol acts directly on the skin, where it is converted into the active form. Ingested vitamin A is used mainly for internal functions — vision, immunity, reproduction — and only a small part reaches the skin. The evidence that oral vitamin A supplements improve the appearance of the skin is much weaker than that for topically applied retinol.

Does retinol make skin more sensitive to the sun?

Yes, retinol can increase the skin's sensitivity to the sun, so daily sun protection is essential during treatment. Laboratory studies show that ultraviolet light can degrade retinol and generate reactive species, although these results are in vitro and do not prove damage to human skin under real conditions of use. The practical recommendation remains: sunscreen in the morning, every day.

Who should not use retinol?

People with very sensitive skin, rosacea or active dermatitis should talk to a dermatologist before use. Pregnant and breastfeeding women should seek advice from a healthcare professional. In children, do not use topical retinol without medical advice. If you are taking other topical or oral medicines, confirm compatibility with a healthcare professional.