Supplements for Sun-Damaged Skin: What Has Evidence and What Doesn't

Sun damage builds up over decades: wrinkles, uneven pigment, broken blood vessels and rough actinic keratoses are all signs of UV injury to skin cells. Supplements do not reverse that damage, and none has been shown to remove existing sun spots or precancerous patches.

What some may do is make skin a little more resistant to new UV damage, or, in one well-designed trial, reduce the number of new precancerous patches and skin cancers in people at high risk. Treatments that actually remove sun damage, such as prescription creams, freezing or procedures, come from a dermatologist.

Moderate: at least one good randomized, placebo-controlled trial that measured outcomes that matter (new skin cancers or precancerous patches) in a clearly defined group.

Limited: small trials, usually measuring sunburn thresholds or laboratory markers of UV damage, often with a few dozen people and sometimes funded by manufacturers.

Weak or none: mostly laboratory or animal studies, or evidence that applies to creams and serums rather than pills.

In the ONTRAC trial (The New England Journal of Medicine, 2015), adults who had had at least two non-melanoma skin cancers took nicotinamide 500 mg twice daily or placebo for a year. The nicotinamide group had about 23% fewer new non-melanoma skin cancers and fewer actinic keratoses. The difference disappeared after people stopped taking it.

A later trial in organ transplant recipients (ONTRANS, 2023) found no benefit, and it has not been shown to prevent melanoma. For people with a history of several skin cancers it is a reasonable question to raise with a dermatologist; for others there is no trial evidence.

This fern extract, sold as an "oral sunscreen", has been tested in small studies. In those, it modestly reduced redness after UV exposure and raised the sunburn threshold in some volunteers, and it eased reactions in some people with sun allergy (polymorphic light eruption).

No study has shown fewer skin cancers, and the protection measured is far below that of sunscreen. The US FDA warned companies in 2018 not to market supplements as a substitute for sunscreen.

Carotenoids are the red, orange and yellow pigments in plants. Small studies of beta-carotene and of lycopene from tomato products found slightly less skin reddening after UV exposure, but only after about 10 weeks or more of daily intake, and the effect was modest. In a study published in the British Journal of Dermatology in 2011, women who ate tomato paste daily for 12 weeks had somewhat less UV-induced redness than a comparison group.

Astaxanthin, a carotenoid from algae, has small trials, mainly from Japan, on skin moisture, wrinkles and sunburn thresholds. They are short and small, so the evidence remains limited. One important caution: high-dose beta-carotene supplements raised lung cancer risk in smokers in large trials, so smokers and recent ex-smokers should avoid them.

Vitamin C and vitamin E have their best skin evidence as creams and serums applied to the skin, where they can reach higher concentrations. Evidence for the pill forms protecting against sun damage is thin: small studies of high-dose combinations found only a slight reduction in sunburn reactions.

Omega-3 fatty acids from fish oil were studied by researchers in Manchester, UK: in small trials, regular doses slightly raised the sunburn threshold and reduced UV-induced suppression of the skin's immune response. These are early markers, not proof of fewer skin cancers. Omega-3 can also interact with blood thinners at higher doses.

Daily sunscreen has the strongest evidence. In the Nambour trial in Australia (Annals of Internal Medicine, 2013), adults who used broad-spectrum sunscreen every day showed no detectable increase in skin aging over four and a half years, unlike those who used it at their own discretion. Shade, hats and clothing add to that.

For existing damage, prescription retinoid creams and dermatologist treatments for actinic keratoses have far better evidence than any pill. And because sun-damaged skin is where skin cancers develop, the most valuable habit is looking at it: any new, changing, rough, bleeding or non-healing spot deserves a doctor's look. Talk to your doctor before starting any supplement, especially if you have had skin cancer, take medicines, or are pregnant.