Produto Skincare · Blog

Retinol: how to start without irritating your skin

By the Produto Skincare team · Updated on November 4, 2026

Published on November 2, 2026 · 6-minute read

Amber serum bottle with the dropper lying next to it, on dark stone, in the warm light of a lamp

Retinol belongs to the retinoid family, some of the most studied ingredients against skin aging. The most studied and most potent ones are prescription retinoids, such as tretinoin; retinol is a milder version sold without a prescription (Mukherjee et al., 2006; Sadick et al., 2023). Even so, it can irritate when used the wrong way. Here is how to start right.

Summary: Start with a low concentration (up to 0.3%), use it only at night, twice a week, and only increase after a few weeks without irritation. Less is more.

What retinol does

Stimulates collagen: softens fine lines. In a randomized trial with older adults, 0.4% retinol applied to the arm up to 3 times a week for 24 weeks improved fine wrinkles and increased collagen (Kafi et al., 2007)
Improves texture and tone: retinoids make the skin smoother and the tone more even (Sadick et al., 2023)

One caveat: for most products sold without a prescription, clinical studies are still few (Sadick et al., 2023).

Retinol vs retinal vs retinoid

Ingredient	Strength	For whom
Retinol 0.1-0.3%	Mild	Beginners, sensitive skin
Retinol 0.5-1%	Medium	People who have used it for 3+ months
Retinal (retinaldehyde)	Milder than tretinoin	People who already tolerate retinol well
Tretinoin (prescription)	Very high	Under a dermatologist's care

In general, the higher the concentration, the higher the chance of redness, peeling and burning (Sadick et al., 2023). Retinol and retinal tend to irritate much less than tretinoin (Mukherjee et al., 2006).

A safe progression (4 weeks)

📅 Weeks 1-2: just the basics

Gentle cleanser + moisturizer + sunscreen
Don't add retinol yet
Your skin needs to get used to the routine

📅 Week 3: first contact

Use retinol twice a week (e.g. Tuesday and Friday)
Only at night, after moisturizer (the "sandwich" technique)
Amount: a pea-sized drop for the whole face

📅 Week 4+: increase slowly

If there was no irritation, go up to 3 times a week, the maximum frequency in the trial mentioned above (Kafi et al., 2007)
After 3 months, if your skin is doing well, consider 0.5%
Avoid using it 2 nights in a row at the beginning

Common mistakes (avoid them!)

❌ Using it every day right away: raises the chance of irritation
❌ Using acids (BHA/AHA) on the same night: irritation can add up
❌ Using it in the morning: some retinoids, such as tretinoin, are very sensitive to light (Martin et al., 1998), which is why they are usually used at night
❌ Forgetting sunscreen: the sun is the biggest factor in facial aging, exactly what retinol is trying to treat (Sadick et al., 2023)
❌ Giving up at the first peeling: mild redness, peeling and dryness are common side effects of retinoids (Sadick et al., 2023). Use it less often; if it burns a lot or doesn't improve, stop and see a dermatologist
❌ Using it during pregnancy on your own: a meta-analysis found no increase in birth defects with topical retinoids, but the data are not enough to justify use during pregnancy (Kaplan et al., 2015). Talk to your doctor

What NOT to combine with retinol

Don't use together	Why	Solution
Salicylic acid (BHA)	Irritation can add up	Alternate days
Glycolic acid (AHA)	Irritation can add up	Alternate days
Pure vitamin C	Irritation can add up	Vitamin C in the morning, retinol at night
Benzoyl peroxide	Breaks down tretinoin, especially under light (Martin et al., 1998)	Use at different times of day

Products to start with

These products are sold in Brazil, where this site is based. Approximate prices in Brazilian reais (BRL).

Principia RN-0,3: 0.3% retinol, great value (R$ ~53)
L'Oréal Revitalift Noturno: affordable, easy to find (R$ ~60)
La Roche-Posay Retinol B3: with niacinamide (R$ ~150)

This is not a medical diagnosis. If you have rosacea, eczema or very sensitive skin, see a dermatologist before using retinol.

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Sources

Mukherjee S, et al. Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety. Clin Interv Aging, 2006. PubMed 18046911 · DOI
Sadick N, et al. Topical Treatments for Photoaged Skin. J Drugs Dermatol, 2023. PubMed 37683070 · JDDonline
Kafi R, et al. Improvement of naturally aged skin with vitamin A (retinol). Arch Dermatol, 2007. PubMed 17515510 · DOI
Martin B, et al. Chemical stability of adapalene and tretinoin when combined with benzoyl peroxide in presence and in absence of visible light and ultraviolet radiation. Br J Dermatol, 1998. PubMed 9990414 · DOI
Kaplan YC, et al. Pregnancy outcomes following first-trimester exposure to topical retinoids: a systematic review and meta-analysis. Br J Dermatol, 2015. PubMed 26215715 · DOI

References checked on PubMed in November 2026. Claims about effectiveness are based on the abstracts of these studies.