Astaxanthin benefits: what's known for skin, eyes and exercise, EFSA's safe intake and how to take it

What astaxanthin is and where it comes from

Astaxanthin is a red pigment from the carotenoid family, a relative of beta-carotene and lutein. It’s what gives salmon, prawns and krill their colour. Animals get it from their diet; microalgae make it.

Supplements are mainly made from the microalga Haematococcus pluvialis. Its cells build up large amounts of astaxanthin and turn red. This algae-based astaxanthin is what EFSA assessed in 2020. A synthetic version also exists, but it’s chemically different from the natural form and less studied.

People usually buy astaxanthin:

• for skin – against sun ageing and dryness;
• for eyes – for screen-related eye strain;
• for exercise – to recover faster.

Claims of the “strongest antioxidant” come from test-tube studies. The US National Center for Complementary and Integrative Health (NCCIH) points out that antioxidant supplements in general haven’t been shown to prevent disease.

Astaxanthin benefits: what trials found

Astaxanthin for skin

A 2021 meta-analysis pooled 9 randomised trials of astaxanthin capsules. Compared with placebo, skin became slightly better hydrated and more elastic. Wrinkle depth didn’t fall significantly – the difference could have been chance.

These trials were small and the effect modest. Simpler steps do more against sun ageing:

• sunscreen every day, and not only on holiday;
• not smoking;
• seeing a dermatologist or GP about new pigment patches.

What else may help your skin is covered in our guides to supplements for skin and collagen.

Astaxanthin for eyes

Evidence for eyes is weaker than for skin. A typical example is a 2021 Japanese trial. 44 adults with eye strain from computer work took a combination of anthocyanins, astaxanthin and lutein, or a placebo, for 6 weeks. Their focusing ability declined less after screen work than with placebo. But the capsules held three ingredients, and the manufacturers funded the study.

Astaxanthin isn’t part of the AREDS2 formula, the supplement combination shown to slow age-related macular degeneration in people who already have it. Who genuinely benefits from eye supplements is explained in our guide to eye vitamins.

Astaxanthin and exercise

A 2026 meta-analysis pooled 24 trials in healthy adults and athletes. Astaxanthin lowered creatine kinase, a marker of muscle damage after exercise. But it didn’t improve VO2max, time-trial results or peak power.

Its authors conclude that astaxanthin may help recovery but doesn’t boost performance. For performance itself, creatine has far more evidence.

Natural vs synthetic astaxanthin

Almost all astaxanthin on iHerb comes from algae, but it’s worth checking the source on the label.

The difference has shaped the limits too. In 2014, EFSA set an acceptable daily intake of 0.034 mg per kg of body weight – about 2.4 mg a day for a 70 kg adult. A 2019 review pointed out that this figure rested on rat studies of synthetic astaxanthin. In 2019 the acceptable intake was revised to 0.2 mg per kg. So older advice of “no more than 2 mg” is out of date.

Food adds some astaxanthin too, from salmon, prawns and other seafood. EFSA took that background intake into account when setting the safe level for supplements.

How much astaxanthin is safe: EFSA’s view

In 2020, EFSA assessed algae-based astaxanthin as a novel food for supplements. Its conclusions:

• Acceptable daily intake: 0.2 mg per kg of body weight. For a 70 kg adult, that’s 14 mg a day from all sources.
• Adults can safely take up to 8 mg a day from supplements, on top of what fish and seafood provide.
• Teenagers aged 14–17 reach exactly the acceptable intake at 8 mg a day.
• Children aged 10–13 would exceed it by 28% at that dose, and younger children by even more.

Recommended limits vary between countries, from 2 to 24 mg a day. A 2019 review of 87 human studies found no safety concerns with natural astaxanthin, including 35 studies at 12 mg a day or more. EFSA’s 8 mg is the benchmark in the EU, and a sensible ceiling in the UK too.

How to take astaxanthin

• Dose. 4–8 mg a day, and no more than 8 mg across all your supplements.
• With food. Like other carotenoids, astaxanthin dissolves in fat. The easy option is to take it with lunch or dinner that includes fish, oil or nuts.
• Other products. Astaxanthin turns up in omega-3, krill oil and beauty formulas. Add the doses together.
• How long. Trials lasted weeks to months. If you notice no difference after 2–3 months, there’s little point continuing.

Astaxanthin safety and who should avoid it

No serious side effects have been reported in trials of natural astaxanthin. There’s little data on interactions with medicines, so if you take regular medication, check with your GP or pharmacist.

Who shouldn’t take astaxanthin:

• Children under 14. 8 mg, together with what they get from food, exceeds their acceptable intake.
• Pregnancy and breastfeeding. EFSA’s conclusions apply to adults, and there’s no safety data for pregnancy.
• Chemotherapy and radiotherapy. NCCIH warns that antioxidants might make these treatments less effective. Only with your oncologist’s agreement.

You can check supplement combinations in our vitamin compatibility chart.

How to choose astaxanthin on iHerb

1. Decide why you want it. If you’re not sure you need a supplement, try our vitamin check.
2. Look for “Haematococcus pluvialis” as the source: that’s the astaxanthin EFSA assessed.
3. Check the dose: 4–6 mg per softgel. 12 mg softgels exceed EFSA’s safe intake.
4. Choose oil-based softgels, since astaxanthin dissolves in fat.
5. Compare the price per 4 mg of astaxanthin and prefer products with independent quality testing.

Our guide to reading a supplement label explains the Supplement Facts panel. More options for skin and hair are in our skin, hair and joints section.