Tretinoin for beginners: how to start and what to expect

Tretinoin is a prescription retinoid applied to the skin to treat acne and to improve some signs of sun damage, such as fine wrinkles and uneven pigmentation. Doctors usually start with a low strength and fewer applications at first, and your doctor decides the exact strength, amount and schedule. Patience matters, because visible results take months rather than days.

Most of the problems beginners run into, such as redness, peeling and an early flare of spots, are predictable and usually manageable. This guide explains what the research actually shows about starting tretinoin, the so-called purge, the sandwich method, and how long it takes to see a difference.

A doctor reviews your case and decides whether tretinoin is appropriate for you, at what strength, and how often.

Key takeaways

- Tretinoin is a prescription-only medicine in Spain, available as 0.025%, 0.05% and 0.1% creams [9].

- Irritation is very common at the start, reported in up to 95% of people using tretinoin, and usually settles as the skin adapts [7].

- An apparent worsening of acne in the first weeks is described in the official product information, but good data on how long it lasts are limited [9].

- In trials, photoageing improves over 4 months to 2 years, and acne is usually assessed after about 12 weeks [1, 3, 4].

- Tretinoin is contraindicated in pregnancy and in anyone planning a pregnancy [9].

What tretinoin is and who it is for

Tretinoin (all-trans retinoic acid) is the original topical retinoid. It speeds up the turnover of skin cells lining the pores, which helps clear existing comedones (blackheads and whiteheads) and makes new ones less likely to form [9]. In sun-damaged skin it activates genes for several important skin proteins, and long-term studies show increased markers of new collagen [3].

In Spain, topical tretinoin is licensed for two uses [9]:

• Mild to moderate acne vulgaris.
• Photoageing: as an add-on to reduce fine wrinkles, mottled pigmentation and roughness on the face, alongside sun protection and moisturisers.

The product information is clear that it is not a cosmetic and must be used under medical prescription [9]. It has not been shown to help the most severe signs of sun damage, such as deep wrinkles or loss of elasticity [9].

Major guidelines strongly recommend topical retinoids as a core acne treatment [6]. A network meta-analysis of 35 randomised trials found that single topical agents, including tretinoin, outperformed placebo, and that combinations of agents were generally the most effective option for mild to moderate acne [5]. You can read how the main retinoids compare in our sibling article on adapalene vs tretinoin vs retinol, and more about acne care on our acne page.

Starting low: strength, amount and frequency

The Spanish product information recommends starting acne treatment with a low concentration once a day, then increasing the strength or frequency according to how your skin responds [9]. For photoageing, the studied strength is 0.05% applied once a night [3, 9].

Strength	Typical role when starting	Notes
0.025%	Common first step, especially for sensitive or dry skin	Lowest licensed strength in Spain [9]
0.05%	Strength used in the photoageing trials	Studied for up to 2 years in sun-damaged skin [3]
0.1%	Usually reserved for skin already used to a retinoid	Highest licensed strength; rarely a starting point

What the Spanish product information describes [9] (your doctor will tell you exactly how to use it):

• A thin layer. The product information describes applying only enough to lightly cover the area. More cream does not work better and causes more irritation.
• Clean, dry skin. It describes applying to clean, dry skin, and many doctors suggest waiting a little after washing.
• Sensitive areas. It describes keeping the cream away from the eyes, eyelids, the corners of the nose and mouth, and skin folds.
• Evening use. Tretinoin is usually applied in the evening.

Doctors often build up gradually, for example starting on alternate nights, and the product information describes spacing out applications if irritation appears [9]. Do not change the schedule on your own: ask the doctor who prescribed it.

The "purge": what to expect in the first weeks

The "purge" is the popular name for a flare of spots soon after starting a retinoid. The Spanish product information describes it directly: in the first weeks of acne treatment, an apparent worsening can occur, attributed to the faster clearing of microcomedones that were already forming under the skin [9].

What the evidence does and does not tell us:

• It is recognised, but large trials rarely measure it separately, so there are no reliable figures on how many people experience it or exactly how long it lasts.
• It is different from irritation. Irritation (redness, stinging, dryness, peeling) is often called retinoid dermatitis. It affects around 85% of people on topical retinoids and up to 95% on tretinoin, and is moderate to severe in about 20% [7].
• It should appear where you usually break out. New types of lesions in unusual places, or a rash with swelling or blisters, point to something else.

Irritation is the main reason people give up: about 15% stop tretinoin because of it [7]. In the photoageing trials, side effects were largely limited to a retinoid reaction that lessened as treatment continued [2]. If you are unsure whether you are purging or reacting, contact your doctor rather than stopping or pushing through on your own.

The sandwich method and other ways to buffer irritation

The "sandwich" method means applying moisturiser, then tretinoin, then another layer of moisturiser. "Buffering" usually refers to the moisturiser-first step.

• Moisturisers can improve tolerance. In a randomised, split-face study, people applied 0.05% tretinoin to the whole face and a moisturiser to one side only. Most had some irritation on both sides (about 83% to 86%), but it was predominantly mild on the moisturised side, and participants preferred that side [8]. The study was in healthy skin and did not test the sandwich order or effects on acne.
• Short contact is another option. In an open pilot study, 74 people with mild to moderate acne applied 0.05% tretinoin for 30 minutes daily and then washed it off. About 55% improved by at least 50%, and only 5.4% stopped because of irritation [7]. There was no control group, so the result needs confirmation.

The limits are important. No good trial has shown that sandwiching keeps tretinoin's full effect, and diluting it may reduce how much reaches the skin. The Spanish product information also advises that moisturisers and cosmetics can be used during treatment but should not be applied at exactly the same time as tretinoin [9]. A sensible compromise is to moisturise at a different time of the evening or in the morning, and to discuss buffering with your doctor if irritation persists.

How long tretinoin takes to work

Tretinoin is slow. The product information notes that improvement in photoageing appears gradually, generally after 3 to 4 months, and that benefits fade if treatment is not maintained [9].

Goal	What trials show	Typical time frame
Acne	Clinically relevant global improvement in 28% to 31% with tretinoin vs 17% with vehicle [4]	Assessed at 12 to 15 weeks [4]
Photoageing, short term	14 of 15 people improved on the face with tretinoin; none on vehicle [1]	16 weeks [1]
Photoageing, longer term	Gains in wrinkling and texture held, lentigines fell by 71% [2]	Up to 22 months [2]
Photoageing, 2-year RCT	Better fine and coarse wrinkling, mottled pigmentation, lentigines and sallowness than placebo [3]	Up to 2 years [3]

Acne

For acne, the 12-week mark is when trials usually judge results [4, 5]. Improvements are real but moderate when tretinoin is used alone, which is why guidelines favour combining treatments with different mechanisms [6]. Our guide to anti-ageing tretinoin covers the photoageing use in more detail.

Photoageing

The landmark 1988 trial was small (30 completers) but double-blind and vehicle-controlled [1]. A later 2-year randomised trial in 204 people with moderate to severe facial photodamage confirmed benefits with 0.05% once daily, and found no increase in abnormal skin cells compared with placebo [3]. Once results plateau, the product information suggests maintenance with 1 to 3 applications a week [9]. For a wider look at what helps ageing skin, see skin ageing: evidence-based treatments and our anti-ageing page.

Safety: irritation, sun, waxing and other products

Most reactions are local and mild to moderate: dryness, peeling, redness, burning, itching and temporary changes in pigmentation [9]. Dryness and peeling tend to persist during treatment but lessen over time [9].

Key precautions from the product information [9]:

• Sun. Tretinoin increases sensitivity to UV light. Avoid or reduce sun exposure, including sunbeds, use a sunscreen of at least SPF 15 when exposure cannot be avoided, and wear protective clothing. Do not apply it to sunburnt skin.
• Waxing and hair removal. Waxes, depilatory creams and electrolysis can irritate treated skin. Avoid them on treated areas unless your doctor says otherwise.
• Other products. Take care with abrasive, drying or peeling products, including some soaps, astringents and products high in alcohol.
• Photosensitising medicines. Tretinoin should not be used with medicines that increase sun sensitivity, such as tetracyclines, thiazides or fluoroquinolones.
• Eczema. It can cause severe irritation on eczematous skin.

The product information also notes that the safety of daily use beyond 48 weeks has not been formally established for the licensed products [9], although the 2-year trial did not find safety concerns [3].

Tretinoin in pregnancy and breastfeeding

Oral retinoids cause birth defects. Topical tretinoin is absorbed far less, with systemic absorption below 2% [9], but the Spanish product information still lists it as contraindicated in pregnancy and in women planning a pregnancy. If you become pregnant while using it, stop and tell your doctor [9].

A teratogen review concluded that the limited human data are reassuring after accidental exposure, while still recommending that topical retinoids be avoided during pregnancy [10]. For breastfeeding, it is not known whether tretinoin passes into breast milk, so it should only be used if the expected benefit justifies the possible risk [9].

When to see a doctor

Speak to a doctor promptly, and consider an in-person dermatologist, if you notice:

• Severe redness, swelling, blistering, crusting or burning that does not settle when you reduce frequency.
• Breakouts that keep getting worse, or deep, painful nodules or cysts.
• Acne that is leaving scars, or that is affecting your mood or confidence significantly.
• A new or changing mole, a non-healing sore, or any spot you are worried about.
• A pregnancy, or plans to become pregnant.

Severe, scarring or treatment-resistant acne may need oral isotretinoin, which guidelines reserve for those situations [6]. Hi Doctor only offers topical skin treatments, so for oral options you should see a dermatologist in person.

Sources

1. Weiss JS, Ellis CN, Headington JT, Tincoff T, Hamilton TA, Voorhees JJ. Topical tretinoin improves photoaged skin. A double-blind vehicle-controlled study. JAMA. 1988;259(4):527-32. PMID: 3336176. https://pubmed.ncbi.nlm.nih.gov/3336176/
2. Ellis CN, Weiss JS, Hamilton TA, Headington JT, Zelickson AS, Voorhees JJ. Sustained improvement with prolonged topical tretinoin (retinoic acid) for photoaged skin. J Am Acad Dermatol. 1990;23(4 Pt 1):629-37. DOI: 10.1016/0190-9622(90)70265-j. https://pubmed.ncbi.nlm.nih.gov/2229490/
3. Kang S, Bergfeld W, Gottlieb AB, et al. Long-term efficacy and safety of tretinoin emollient cream 0.05% in the treatment of photodamaged facial skin: a two-year, randomized, placebo-controlled trial. Am J Clin Dermatol. 2005;6(4):245-53. DOI: 10.2165/00128071-200506040-00005. https://pubmed.ncbi.nlm.nih.gov/16060712/
4. Leyden JJ, Shalita A, Thiboutot D, Washenik K, Webster G. Topical retinoids in inflammatory acne: a retrospective, investigator-blinded, vehicle-controlled, photographic assessment. Clin Ther. 2005;27(2):216-24. DOI: 10.1016/j.clinthera.2005.02.009. https://pubmed.ncbi.nlm.nih.gov/15811485/
5. Kakpovbia EE, Young T, Milam EC, et al. Efficacy of topical treatments for mild-to-moderate acne: a systematic review and meta-analysis of randomized control trials. J Eur Acad Dermatol Venereol. 2025;39(4):775-784. DOI: 10.1111/jdv.20154. https://pubmed.ncbi.nlm.nih.gov/38943431/
6. Reynolds RV, Yeung H, Cheng CE, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2024;90(5):1006.e1-1006.e30. DOI: 10.1016/j.jaad.2023.12.017. https://pubmed.ncbi.nlm.nih.gov/38300170/
7. Veraldi S, Barbareschi M, Benardon S, Schianchi R. Short contact therapy of acne with tretinoin. J Dermatolog Treat. 2013;24(5):374-6. DOI: 10.3109/09546634.2012.751085. https://pubmed.ncbi.nlm.nih.gov/23167277/
8. Schorr ES, Sidou F, Kerrouche N. Adjunctive use of a facial moisturizer SPF 30 containing ceramide precursor improves tolerability of topical tretinoin 0.05%: a randomized, investigator-blinded, split-face study. J Drugs Dermatol. 2012;11(9):1104-7. PMID: 23135655. https://pubmed.ncbi.nlm.nih.gov/23135655/
9. AEMPS, CIMA. Ficha técnica: tretinoína 0,5 mg/g crema (nregistro 60141), section 4; prescription condition "Medicamento sujeto a prescripción médica" for the 0,25, 0,5 and 1 mg/g creams (nregistro 60140, 60141, 60142). https://cima.aemps.es/cima/dochtml/ft/60141/FT_60141.html
10. Williams AL, Pace ND, DeSesso JM. Teratogen update: topical use and third-generation retinoids. Birth Defects Res. 2020;112(15):1105-1114. DOI: 10.1002/bdr2.1745. https://pubmed.ncbi.nlm.nih.gov/32643315/