Astaxanthin: Real (But Narrow) Eye, Skin & Exercise Evidence

What to buy

We Like Vitamins Astaxanthin is our pick. It is on NSF’s public testing list, which checks that a product matches its label, and it costs the least per milligram of the products we compare. One softgel gives 10 mg for $0.15 a day.

Drug-tested athlete? Informed Choice, which tests for banned substances, lists Nutrex Hawaii BioAstin 12 mg. It costs more, $0.69 a day.

Where to go next

• Best astaxanthin: the products we compared, ranked.
• Astaxanthin dosage guide: how much trials used, with a calculator.

What astaxanthin does

Astaxanthin is the pigment that makes salmon and shrimp pink. Supplements extract it from an algae, Haematococcus pluvialis. It is an antioxidant, but you do not need it the way you need a vitamin, so each claim has to stand on trials.

Astaxanthin for eye strain from screens

Three trials tested it, and the makers of the products paid for all three.

• In 60 adults who worked at screens, 9 mg a day for 6 weeks did not help the group as a whole. Adults 40 and older kept sharper vision in their main eye after screen work (Sekikawa 2023).
• A pill with 3 mg of astaxanthin plus anthocyanin and lutein helped the eyes focus after screen work in 6 weeks; the trial cannot show which ingredient did it (Kizawa 2021).
• In 64 children aged 10 to 14 with lots of screen time, 4 mg a day for 12 weeks lowered eye-strain scores more than placebo; eye tests such as sharpness of vision did not change (Hecht 2025).

No trial shows astaxanthin treats or prevents an eye disease.

Who paid for the trials

Many of the trials were paid for by companies that sell astaxanthin. FUJIFILM paid for the main skin trial (Ito 2018); BGG Japan for the eye trials (Sekikawa 2023; Kizawa 2021); AstaReal’s maker, Fuji Chemical, for the children’s eye trial (Hecht 2025) and a cholesterol trial (Ciaraldi 2023). That does not make the results wrong, but it is a reason for caution.

How long the trials ran

Most trials ran 4 to 24 weeks. The skin trial measured after 9 to 10 weeks, the adult eye trial at 6 weeks, and the children’s eye trial at 12 weeks. No trial tested a same-day effect. Most trials gave 4 to 12 mg a day; see the dosage guide.

Is astaxanthin safe?

A review of 87 human studies found no safety concerns, 35 of them at 12 mg a day or more (Brendler 2019). In 2020, Europe’s food safety agency found up to 8 mg a day from supplements safe for adults (EFSA 2020). A few things to check:

• Warfarin or another blood thinner: ask your doctor. In one reported case, a woman’s clotting test (INR) rose from 1.4 to 10.4 a day after she added astaxanthin; she took other medicines too (Santiyanon 2019).
• Diabetes or blood pressure medicine: trials found lower blood sugar, and two lower blood pressure (Mashhadi 2018; Waldman 2023); ask your doctor.
• Children and teens: EFSA found 8 mg a day too much for children under 14, and right at the limit for teens 14 to 17, once food is counted.
• Pregnant or breastfeeding: there are no trials; ask your doctor first.

Questions people ask