One of the most persistent myths in skincare is that retinoids — including prescription tretinoin and over-the-counter retinol — must be stopped during summer. This article examines what the evidence actually says and how to continue retinoid use safely during warmer months.

Tretinoin is a prescription-only medicine in the UK. This article is for educational purposes only. Always follow the guidance of your prescribing clinician.

Where the myth comes from

The misconception has a basis in fact: retinoids increase skin sensitivity to UV radiation. Tretinoin accelerates epidermal cell turnover, thinning the stratum corneum, which can make skin more susceptible to UV-induced irritation and damage. This nuance — that retinoids require better sun protection, not discontinuation — has been oversimplified into blanket advice to stop using them in summer.

What the evidence says

There is no clinical evidence that tretinoin or retinol must be discontinued during summer. Dermatologists routinely recommend year-round use, particularly for conditions such as acne, hyperpigmentation, and photoageing, which benefit from consistent long-term treatment. Interrupting treatment in summer means losing months of progress and potentially restarting the adjustment period when use resumes.

Retinoids are not rendered inactive by sun exposure on the skin. Some formulations can degrade if exposed to light in the bottle — which is why they are packaged in opaque containers and applied at night — but this is a storage consideration, not a reason to stop treatment.

How to use retinoids safely in summer

• Apply at night only. This is standard practice regardless of season. Nighttime application avoids direct UV exposure and reduces the risk of photodegradation.
• Use broad-spectrum SPF 50 every morning. This is a clinical requirement of tretinoin treatment at any time of year. In summer, reapplication during the day is particularly important if spending time outdoors.
• Support the skin barrier. Ceramides, niacinamide, and humectants such as hyaluronic acid help maintain barrier integrity during the adjustment period and in conditions of heat and increased sweating.
• Use physical protection. Wide-brimmed hats, UV-protective clothing, and seeking shade during peak UV hours (10am–4pm) reduce cumulative UV exposure.

When reducing frequency is reasonable

Stopping tretinoin in summer is not necessary, but temporarily reducing application frequency may be appropriate in specific circumstances:

• Extended periods of unavoidable direct sun exposure with limited shade (e.g. a beach holiday)
• Increased skin irritation due to heat, sweat, or swimming
• Recent increase in concentration or formulation change, with skin still in the adjustment period

Any changes to application frequency should be discussed with your prescriber. Reducing frequency temporarily is preferable to stopping entirely.

Retinol vs tretinoin in summer

The same principles apply to over-the-counter retinol, though the photosensitivity effect is less pronounced given retinol's lower potency. Users of retinol who are not yet on prescription tretinoin should still apply at night and use daily SPF. For a comparison of retinol and tretinoin, see our article on retinol safety. For guidance on situations where tretinoin should be avoided entirely, see our article on tretinoin contraindications. For information on accessing tretinoin legally in the UK, see our no-nonsense guide to buying tretinoin.