Astaxanthin

Astaxanthin is the red carotenoid pigment that colours salmon, krill and shrimp, and it is usually sold as an extract of microalgae. Small trials suggest possible effects on skin and on markers of exercise recovery, but the evidence is limited, and for eyes and cognition it is insufficient. EFSA considers up to 8mg a day from diet and supplements safe for adults.

What is astaxanthin?

Astaxanthin is a carotenoid, related to beta-carotene and lutein, but it is not a vitamin and the body has no requirement for it. Most people obtain small amounts from seafood. Supplements typically use astaxanthin from the microalga Haematococcus pluvialis.

Astaxanthin is often described as a far stronger antioxidant than vitamin E. In laboratory tests it does inhibit lipid oxidation many times more strongly than vitamin E. Laboratory potency is not evidence of a benefit in people, and the human trials below are what matter.

Solgar Astaxanthin 5mg 30 Softgels Higher Nature Astaxanthin and Blackcurrant 90 Capsules

Does astaxanthin work?

Skin

Evidence: Limited.

A systematic review of clinical studies found 11 trials, six of them randomised, double-blind and placebo-controlled. Doses were typically 4-12mg a day for 8-16 weeks, with reported improvements in skin moisture, texture and redness after UV exposure. The trials are small and short and use cosmetic or surrogate measures. It is not a replacement for sun protection.

Exercise recovery and performance

Evidence: Limited.

A meta-analysis of 24 randomised trials found lower blood levels of creatine kinase and lactate dehydrogenase, markers of muscle stress, although the results varied considerably between trials. Evidence for improved performance is less consistent, with one analysis of nine trials suggesting a possible improvement in cycling time trials.

Eye strain and eye health

Evidence: Insufficient.

One randomised trial in 64 children with digital eye strain found symptom improvement with 4mg a day over 84 days. That is a single trial in one population, and adult evidence is limited to small studies.

Cognition

Evidence: Insufficient.

A systematic review found too few studies to draw a conclusion. In a trial of 54 middle-aged adults, 8mg a day for eight weeks did not significantly improve cognitive function compared with placebo.

Cholesterol, inflammation and other claims

Evidence: Insufficient.

Claims that astaxanthin improves cholesterol or reduces chronic inflammation rest mainly on laboratory and animal work. No reliable human evidence supports them.

Doses used in research

Trials used 4-12mg a day, most for 8-16 weeks. EFSA concluded that a combined intake of up to 8mg a day from food and supplements is safe for adults, equivalent to an acceptable daily intake of 0.2mg per kg body weight. These are study doses and a regulatory safety figure, not a recommended intake.

Safety

Astaxanthin was well tolerated in trials at 4-12mg a day for up to a year, and reviews of human studies have not identified serious safety concerns. Data are insufficient for pregnancy, breastfeeding and use in children outside trial settings, and no interaction with medicines has been established in the sources reviewed.

Alessandro Grenci, Superintendent Pharmacist at Medino:

"Two things to check on a label are the amount of astaxanthin per serving and whether it exceeds EFSA's 8mg a day figure, since some products list larger doses. 'Antioxidant strength' comparisons on packaging come from laboratory tests, so they can't be read as a sign of how the product will perform in the body."

Is astaxanthin worth taking?

The evidence for skin and exercise recovery is limited and based on small, short trials, and for eyes and cognition it is insufficient. Its safety profile at the doses studied is reassuring, but the benefit is not established. Anyone who is pregnant, breastfeeding or taking regular medicines should speak to a pharmacist or GP before using it.

Sources

  • Vitamin E - the antioxidant astaxanthin is often compared with in laboratory tests.
  • Omega-3 - another marine-derived supplement, with much more human research.
  • Collagen - also marketed for skin appearance.
  • Ubiquinone (CoQ10) - another antioxidant supplement, with evidence in specific uses.
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