Benefits
Skin redness after UV exposure
In a placebo-controlled trial, healthy adults taking 240 mg twice daily for 60 days had fewer sunburns and were more likely to need a higher UV dose before their skin reddened. Two studies without a placebo group also found less UV redness after the extract. The effect is partial: it is used with sunscreen, not instead of it.
Skin reactions to sunlight in light-sensitive people
In two open studies without a placebo group in people prone to a sun-triggered rash (polymorphic light eruption), 30 percent stopped reacting to UVA after the extract and the rest needed more exposures to react, and about 74 percent of 57 patients taking 480 mg a day reported fewer skin reactions. Without placebo groups these results are uncertain.
DNA damage markers after UVA exposure
In a 30-day trial in 50 healthy volunteers comparing the extract (480 mg a day) with nicotinamide, both raised the UVA dose needed to redden the skin by 26 percent, but neither reduced UVA-induced DNA damage (thymidine dimers) in skin or urine. There was no placebo group.
Antioxidant and anti-inflammatory activity (laboratory and animal studies)
In laboratory and animal studies the extract lowered UV-induced COX-2, p53 mutations, DNA lesions, sunburn cells and inflammatory cell infiltration, and it is described as a strong antioxidant. No cited human study measured antioxidant or inflammatory markers in the blood.
Steroid cream use unchanged in a 105-child skin trial
In a 6-month placebo-controlled trial in 105 children and teenagers with moderate atopic dermatitis on standard care, the extract did not reduce the share of days on which steroid creams were used (11 vs 12 percent), the main goal. Days using oral antihistamines were fewer (4.5 vs 13.6 percent).
Mechanism of action
Antioxidant activity
The extract is described as a strong antioxidant and anti-inflammatory agent, and reactive oxygen species are thought to play a part in sun-triggered rashes. This is the main proposed reason it could reduce UV skin reactions.
UV damage markers in laboratory and animal studies
In laboratory and animal work, the extract lowered UV-induced COX-2, p53 mutations, cyclobutane pyrimidine dimers (DNA lesions), epidermal proliferation, sunburn cells and inflammatory infiltrate. A human trial did not find less UVA-induced DNA damage.
Raising the skin's UV threshold
In people, the measurable effect is a higher dose of UV needed to cause redness and less redness at a given dose, seen after a single day of dosing and after several weeks of use.
Clinical trials
Randomized, double-blind, placebo-controlled single-center trial of 240 mg twice daily for 60 days (Nestor et al. 2015, J Clin Aesthet Dermatol)
Healthy men and women aged 18 to 65 with Fitzpatrick skin types I to IV.
More placebo takers had more than one sunburn (8 vs 2). At day 28, more extract takers had a higher minimal erythema dose (8 vs 1) and less UV-induced redness (10 vs 3). Safety tests, including blood counts, metabolic panel and clotting times, did not change.
Open study comparing skin responses to visible light, UVA1 and UVB before and after two 240 mg doses (480 mg total) (Kohli et al. 2017, J Am Acad Dermatol)
22 adults with skin types I to III.
UVB-induced changes decreased in 17 of 22 people on clinical and color measurements and in all 22 on biopsy. Only 2 doses were given, there was no placebo, and several authors were investigators for the extract's supplier.
Open, uncontrolled study at two centers with UV photoprovocation before and after 2 weeks of oral extract (Tanew et al. 2012, J Am Acad Dermatol)
35 patients with long-standing polymorphic light eruption.
Of 30 patients who reacted to UVA, 9 (30 percent) no longer reacted after the extract, and of 18 who reacted to UVB, 5 (28 percent) no longer reacted. In the rest, the number of exposures needed to trigger the rash rose significantly. No placebo group.
Uncontrolled study of 480 mg a day during sun exposure (Caccialanza et al. 2011, G Ital Dermatol Venereol)
57 patients, 53 with polymorphic light eruption and 4 with solar urticaria.
About 74 percent reported benefit, with fewer skin reactions and symptoms than at baseline. No side effects were observed. There was no control group.
Randomized intraindividual trial of 480 mg a day of the extract (Heliocare Advanced) or 2,000 mg a day of nicotinamide for 30 days (Faisal et al. 2026, Photochem Photobiol Sci)
50 healthy volunteers with skin types I to III.
Both raised the minimal erythema dose for UVA by 26 percent. Neither reduced UVA-induced thymidine dimers in skin or urine, so the DNA-damage outcome was negative. There was no placebo arm.
Randomized, double-blind, placebo-controlled multicenter trial of the extract in capsules for 6 months alongside standard care (Ramírez-Bosca et al. 2012, Actas Dermosifiliogr)
105 patients aged 2 to 17 with moderate atopic dermatitis using topical corticosteroids.
The primary outcome was null: the share of days using topical corticosteroids did not fall (11 vs 12 percent with placebo). Oral antihistamine use was lower (median 4.5 vs 13.6 percent of days).
Randomized, double-blind, placebo-controlled trial of 250 mg three times daily with narrow-band UVB twice weekly for 25 to 26 weeks (Middelkamp-Hup et al. 2007, J Eur Acad Dermatol Venereol)
50 patients with vitiligo vulgaris.
Head and neck repigmentation was 44 vs 27 percent, which was not statistically significant (p = 0.06); other body areas showed no significant difference. In patients attending more than 80 percent of light sessions, head and neck repigmentation was higher (50 vs 19 percent).