When it comes to acne and the sun, anecdotes abound: some tout it as a clogged-pore cure-all, still others say their breakouts reach new levels come summertime. But what does the science say?

Spoiler alert: it’s complicated. Researching the effects of sun exposure in general can be problematic, and the fact that our skin is an incredibly intricate, interwoven system doesn’t make things any easier. With the help of Dr. Sandra Lee (aka Dr. Pimple Popper), we present both sides of the story before weighing in on whether sunlight can clear up acne.

Can tanning treat acne?

We’ve debunked this myth already, but let’s take a deeper look — because there’s actually a reason it got started. Remember that sunlight is composed of a spectrum of wavelengths, including visible light as well as other types of radiation, like ultraviolet. Some of these light wavelengths have been shown to temporarily improve the appearance of acne by:

• Amping up melanin production. In some cases, getting a tan (or even a sunburn) essentially camouflages existing acne, making it seem less apparent. The tradeoff? Long-term photodamage.
• Suppressing the immune system. UV (and to a lesser degree, visible red) rays can reduce the redness of inflammatory acne by dampening the skin’s immune response. The effect doesn’t help acne long-term, and it damages skin by weakening its defenses.
• Inhibiting pathogens. Ultraviolet, as well as blue wavelengths have antiseptic properties: that is, they’ve been shown to kill bacteria, including C. acnes. However, data has not shown that this works better than conventional treatments, particularly benzoyl peroxide.

Experts now agree that basking in the sun to treat acne does more harm than good. But old habits die hard — especially when they’re being propped up by the tanning industry. Though we’ve known the hazards of UV exposure at least since the 1970s, tanning bed usage remains popular in some parts of the country. As recently as ten years ago, a congressional committee investigating the dangers of tanning beds uncovered widespread fraud, with many salons lying about the safety — and purported acne-clearing benefits — of their services.

Though large scale consumer education efforts have helped spread the word, the legend that tanning (and sunbathing) and reduces acne persists — probably because a subset of people do experience a noticeable difference during the summertime.

Can sunlight make acne worse?

Most dermatologists will tell you that many patients experience their acne worsening — not improving — during the summer months. It reinforces the fact that there’s still so much we don’t know about how light — both visible and invisible — affects our skin. But studies have shown conclusively that UV radiation causes both short and long-term damage, in large part by generating oxidative stress.

While more research is needed, radiation is believed to exacerbate acne in several ways, including:

• Elevating sebum production. UVB exposure may increase the quantity, size and output of sebocytes.
• Oxidizing lipids. Squalene, a key component of sebum, protects skin by absorbing UV energy, which changes it into harmful squalene hydroperoxide.
• Increasing transepidermal water loss (TEWL). Dehydrated skin is more vulnerable to environmental stress and microbes, like C. acnes.
• Weakening the skin barrier. UVB radiation damages the cohesion of the stratum corneum, the outermost protective layer of skin cells.
• Inciting inflammation. The skin's immune response to radiation releases a cascade of chemicals that can harm cells.
• Altering DNA. Both UVA and UVB radiation can lead to dangerous cell mutations that leave skin more prone to dysfunction.

In spite of dermatologists’ advice, historically many people with acne prone skin have been reluctant to slather on thick, pore-clogging sunscreen that often makes acne worse. But effective, lightweight formulas like SLMD Dual Defender — offering broad-spectrum UVA/UVB protection — are making it easier for people with acne to opt for routine sun protection.

Why does sunlight help some people with acne?

The debate about the role that sunlight, particularly UV radiation, plays in overall skin health is still very much ongoing. Part of the reason why we don’t have more definitive answers is that it’s very hard to study the effects of sunlight objectively — there are so many variables, from exact weather conditions to the unique temperament of the skin cells being tested. But studying only certain forms of light — UVA, for example — while useful, can also generate data that is out of context from real-life situations.

Complicating things further, researchers have speculated that there may be another reason why moderate levels of sun exposure might benefit chronic skin conditions like acne: vitamin D. Remember that in order to produce this essential nutrient, your skin needs exposure to UV rays. Because vitamin D plays a crucial role in skin health — including immune regulation, inhibiting bacteria, and wound healing — getting the optimal amount through sunlight may be a difference maker in acne management.

As we’ve said before, it’s important to find a balance between generating vitamin D and avoiding things like photodamage and skin cancer. As Dr. Lee explains, wearing sunscreen and producing vitamin D are perfectly compatible. Most people don’t reapply sunscreen often enough, so we’re generally getting some unprotected exposure throughout the day. Remember also that chemical sunscreens (like Dual Defender) take about 15 minutes before they start working.

Different Fitzpatrick skin types have different sun exposure needs. So if you’ve got questions about your optimal UV levels, talk to your dermatologist.

Dr. Lee’s last word

Even though people are becoming more educated about the dangers of too much sun exposure, I still get a lot of questions from my patients about whether or not the sun is good for clearing up their acne. Sunbathing is not a cure for acne, and it can do irreparable damage to your skin. It’s best to find an effective skincare regimen, like my SLMD Acne System, and use a non comedogenic sunscreen like Dual Defender every day.

—Dr. Sandra Lee


Contributing sources:

Inflammatory Cytokine Expression and Sebum Production after Exposure of Cultured Human Sebocytes to Ultraviolet A Radiation and Light at Wavelengths of 650 nm and 830 nm

Effects of UV irradiation on the sebaceous gland and sebum secretion in hamsters

Solar UV radiation reduces the barrier function of human skin

Ultraviolet Phototherapy and Photochemotherapy of Acne Vulgaris