We're all familiar with sunburn—the short-term skin inflammation caused by overexposure to the sun. Besides the familiar redness, pain, blistering, and flaking, overexposure to sunlight can lead to long-term skin damage, including premature aging and an increased risk of skin cancer.

The chief culprit in sunburn is not the sun's heat but its ultraviolet radiation, which occurs in the forms UVA and UVB. This radiation acts on substances in our skin to form chemicals called free radicals. These free radicals appear to be partly responsible for the short-term damage of sunburn, and perhaps for long-term damage from the sun as well.

Conventional approaches to sunburn focus on prevention: staying out of the sun (especially when the sun is strongest), wearing protective clothing, and using sunscreen. Sunscreen blocks much of the radiation from our skin and helps prevent inflammation. A recent study of 1,383 Australians suggests that regular sunscreen use may also diminish the number of tumors caused by one form of skin cancer, squamous cell carcinoma.1

Many drugs and herbs may increase your sensitivity to the sun. Some of the drugs that increase sun sensitivity are sulfa drugs, tetracycline, phenothiazines, and piroxicam. Herbs which might increase sensitivity to the sun include St. John's wort and dong quai. Particular care should be taken when combining any of these substances, as they could amplify each other's effects.

Principal Proposed Natural Treatments

Several studies have found that vitamins C, vitamin E, and EGCG (a bioflavonoid present in green tea) may help to prevent sunburn when used either topically or orally. Many manufacturers already add vitamin E to sunscreens.

Antioxidants such as vitamins C and E neutralize free radicals in the blood and in other parts of our bodies. Test tube and animal studies suggest that they perform the same job in the skin. Levels of these antioxidants in skin cells decrease after exposure to ultraviolet radiation, suggesting they may be temporarily depleted.2,3

In several animal studies, vitamins C and E applied topically to the skin helped to protect against ultraviolet damage.4-7 One study found that topical vitamin E seemed to work best against UVB, topical vitamin C protected more against UVA, and the two vitamins together worked better than either one by itself.8 Vitamin E was effective even when applied to mouse skin 8 hours after ultraviolet exposure had occurred.9 Combining the vitamins with sunscreen yielded the best result, adding to the UV-protection offered by sunscreen alone.10

In addition, preliminary evidence from a small double-blind, placebo-controlled trial suggests that a face cream containing vitamin C could improve the appearance of sun-damaged skin.11

Oral use of combined vitamins C and E may offer very modest benefit as well. One double-blind study of 10 people found that 2 g of vitamin C and 1,000 IU of vitamin E taken for 8 days resulted in a modest decrease in skin reddening induced by ultraviolet light.12 A 50-day, placebo-controlled study of 40 people found that high doses of these vitamins in combination provided a minimal, but statistically significant, sun-protection factor of about 2.13 (Compare this to the sun protection factor of 15 to 45 in many sunscreens.)

One study found benefits with a combination of vitamins E and C, selenium, oligomeric proanthocyanidins (OPCs), and carotenoids.53 However, so far research hasn't found that vitamin E and C, taken separately, are any more helpful than placebo.14,15

For more information, including dosage and safety issues, see the full articles on Vitamin C and Vitamin E.

Green tea contains a potent antioxidant known as epigallocatechin gallate, or EGCG. According to several studies, mice given green tea to drink or topical applications of green tea were protected against skin inflammation and carcinogenesis caused by exposure to UVB.30,31 Benefits were also seen in two preliminary human trials.32,33

The typical proposed dose of EGCG is 3 mg per square inch of skin.

Other Proposed Natural Treatments

Beta-carotene belongs to a large family of natural chemicals known as carotenoids. Other members of this family include lutein, lycopene, and zeaxanthin. Widely found in plants, carotenoids are a major source of the red, orange, and yellow hues seen in many fruits and vegetables. Beta-carotene is important nutritionally because the body uses it to produce vitamin A.

Beta-carotene, alone or in combination with lutein and other carotenoids, may be able to reduce the effects of sunburn, but study results are mixed.

In a double-blind study, 20 young women took 30 mg daily of beta-carotene or placebo for 10 weeks before a 13-day stretch of controlled sun exposure at a sea-level vacation spot.34 Those who'd taken the beta-carotene before and during the sun exposure experienced less skin redness than those taking placebo, even when both groups used sunscreen.

A 12-week, double-blind, placebo-controlled study found beta-carotene (at 24 mg daily) and a mixture of beta-carotene, lutein, and lycopene (at 8 mg each daily) equally protective against sun-induced skin redness.54 Another small double-blind trial found that a mixture of lutein and the related carotenoid zeaxanthin provided benefits when taken orally, applied topically, or, even better, both taken orally and applied topically at the same time.58

Two open studies of mixed carotenoids found similar results. These trials, one of 20 and one of 22 people, found that after taking mixed carotenoids for 12 to 24 weeks, participants could tolerate more ultraviolet radiation before developing skin redness.35,36 Vitamin E (500 IU per day) taken along with beta-carotene in one of the studies didn't significantly affect the results.37 Another study found benefits with tomato paste (rich in lycopene).55 However, since these studies weren't double-blind, the results are not very reliable.

Not every study has found beta-carotene or mixed carotenoids to be helpful. In a double-blind trial of 16 older women, high doses of beta-carotene taken for 23 days didn't provide any more protection than placebo against simulated sun exposure.38 Another 10-week study found that high doses of beta-carotene provided greater protection against natural sunshine than placebo, but the benefits, though statistically significant, were too minor to matter.40 Completely negative results were seen in a 4-week uncontrolled study of high doses of mixed carotenoids.39

The substances collectively called OPCs, found in pine bark and grape seed, have shown some promise for sunburn protection.56

Chocolate contains polyphenol flavonols similar to those in green tea. A special form of chocolate enriched in flavonol content might, like green tea extracts, modestly protect the skin from sun damage.57

Very weak evidence hints at benefit with an extract of the shoots of the Vitis vinifera plant (the common grape vine),59 as well as with an extract of sage.60

Although research information is lacking, topical jojoba, poplar bud (Populi gemma), and Aloe vera are sometimes recommended for soothing sunburn pain and itch. However, one small study found that applying aloe vera gel after UVB exposure had no effect on skin redness.52

In a preliminary, double-blind blind study, coriander oil applied topically was more effective than a placebo cream at reducing redness due to UVB exposure.61