Choosing the best sunscreen is already a daunting task, what with the myriad of confusing SPF options, sprays, sticks, and lotions, mineral versus chemical, water-resistant or sheer, and so on. The task has only been made more confusing in the past few years as new (and often expensive) sunscreens have begun to market themselves as protection not only from ultraviolet rays, but from blue light as well.
Emitted by both the Sun and electronic screens, blue light is the higher energy, smaller wavelength end of the visible light spectrum. It’s close in wavelength to skin’s No. 1 frenemy, UV light. Blue light has already stirred worry in the past over disruptive effects it could have on our circadian rhythms as a result of late-night scrolling. But when it comes to blue light’s ability to cause skin damage, the science is mixed.
Dermatologists and photobiologists have been researching blue light’s effects on skin over the past decade and have published contradicting results, some finding that it can cause skin cell death, hyperpigmentation, aging and the production of free radicals, while others have found more positive effects in the form of wound healing in rats, the clearing of acne, and treatment of jaundice in newborns. The discrepancy between harmful and helpful effects of this high-energy visible light might come down to the dosage strength and duration, photobiologist Frank de Gruijl told Gizmodo in an email.
“This is the crucial matter: the dosages incurred within a certain time frame, before damage is repaired or damaged cells replaced.”
While some studies purposely designed experiments that mimicked the amount of blue light you might experience on an average sunny day, others amped up the intensities much higher to see noticeable effects on the skin. These intensities, whether “normal” or amped up, are far beyond what the average person could expect to experience emanating from their phone or computer screen.
In an excellent blog post tackling this question, chemist and science communicator Michelle Wong compared different brightness studies and found that brighter screens like an iMac were 100 times less damaging than the Sun’s visible spectrum alone, and smaller screens like a smartphone were 2,000 times less damaging.
So while you probably needn’t worry about the small amount of blue light that comes from screens, what about all the blue light coming from the Sun? In one study, researchers found that in human skin irradiated by sunlight, 67 percent of free radicals generated were caused by UV light, while 33 percent were caused by visible light. Since free radicals can cause cancer and other skin damage, preventing their formation is the main purpose of sunscreen. Another experiment found that melasma patients who used a sunscreen that included visible light protection (in the form of iron oxides, a pigment often used in tinted sunscreens) saw greater fading of darkened patches on their skin than patients who were only protected from UV light.
If you’re concerned about hyperpigmentation or skin aging, the limited research available may be enough to push you toward the high-end sunscreen aisles for extra protection. But getting a product with blue light protection isn’t as simple as looking at the label. While the Food and Drug Administration regulates claims around SPF (a number that tells you how much UVB, or sunburn, protection that a product offers) as well as “broad spectrum” (a term that means a product offers at least some UVA protection, helping to prevent tanning), the agency does not regulate claims about blue light protection. That means it’s not possible for a consumer to know whether product is offering a high level of blue light protection or merely the blue-light equivalent of an SPF 2.
According to Supergoop director of product development Sofia Gracia, there isn’t much difference between a run-of-the-mill UV-protecting sunscreen and the blue light protecting formula in the company’s Unseen Sunscreen.
“Red algae is the only blue light-fighting ingredient in the formula. This single ingredient is able to provide [high-energy visible light] protection, helping to absorb the blue/violet portion of the spectrum to protect the skin from its damaging effects,” Gracia told Gizmodo in an email. In other words, this formula isn’t much different from any other sunscreen, other than the addition of red algae, which is listed among the product’s ingredients as Lithothamnion Calcareum Extract.
In the deep ocean, red algae is an efficient absorber of blue light thanks to its carotenoid pigments, which absorb blue light and reflect red. However, while research does seem to support red algae’s ability to stave off aging effects from UVA rays, it’s not clear how much blue light the algae’s extract is actually able to absorb when it’s formulated into a lotion and slathered on your skin.
Another formula that markets itself as providing blue light protection, an SPF 50 sunscreen from Murad, contains iron oxides and a carotenoid called yellow lutein. Iron oxides provide visible light protection, and lutein absorbs blue light.
“City Skin Age Defense SPF 50… contains lutein from marigold flowers which is very effective at absorbing blue light,” Emily Philen, senior manager of product development at Murad, told Gizmodo in an email. “Both titanium dioxide and zinc oxide (the sunscreen actives) [also] naturally block some blue light.”
Despite the body of research showing that the Sun is the most concerning source of blue light exposure, both these products market themselves as protection from screens. In the product description for Unseen Sunscreen, Supergoop describes the sunscreen as “help[ing] protect your skin from the blue light that’s emitted by your phone and computer,” and Murad’s City Skin product description says it protects from “blue light from devices.”
Despite these marketing claims, blue light from screens is likely not giving you wrinkles or spots, according to Alexander Wolf, a senior assistant professor at the Institute of Advanced Medical Sciences at Nippon Medical School who contributed to a 2017 paper that found blue light at sunlight-level intensities could promote skin stress and aging effects.
“Direct sunlight is something to worry about, and blocking blue … is a good way to protect yourself from direct sunlight,” Wolf told Gizmodo in an email. “[Otherwise] there is little reason for concern for the really ‘average’ person, because most skin damage and skin cancer is caused by the UVB component of sunlight, which damages DNA directly… smart screens have far too little light intensity to be relevant for aging effects.”
But, ultimately, Wolf thinks that having more choice in protection is never a bad thing.
“Skin aging [makes] quite a lot of people nervous,” Wolf said in his email. “So [blue light] protection is nice to have, I would say. A sign of progress.”
Ultimately, no sunscreen will fully protect you from the deadly laser that is our star, so the best approach is to choose a sunscreen you don’t mind applying liberally and reapplying frequently, and rely on things like hats, clothing, shade, and simply staying inside at midday to keep your skin healthy.
Sarah Wells is a freelance writer based in Boston writing about the intersection of technology, science, and society. Follow her on Twitter: @saraheswells.