Also known as: Haematococcus pluvialis, AstaReal, AstaPure, Algal astaxanthin
EnduranceGood evidence
A deep red carotenoid from microalgae, and the pigment that makes salmon and flamingos pink. Studied for endurance, skin and eye measures, and unusual among carotenoids in reaching tissues others cannot.
Typical dose
4.0–12.0 mg per day
With a fat-containing meal; allow 6-12 weeks
What it is
Astaxanthin is a xanthophyll carotenoid produced by the microalga Haematococcus pluvialis, which accumulates it in response to stress. It is what turns salmon, trout, shrimp and flamingos pink, since all of them obtain it through the food chain.
Commercial astaxanthin is either grown from the algae or produced synthetically. The synthetic version, used largely in fish farming, differs in isomer composition from the natural material and is not equivalent. Supplements should specify algal origin.
Its colour is remarkable — astaxanthin is intensely red, and even small amounts colour a product deeply. Being fat-soluble, it needs to be taken with fat, and softgels in an oil base considerably outperform dry capsules.
How it works
Astaxanthin's molecular structure allows it to span the cell membrane, with its ends protruding into both the water-based environments either side. That means it can neutralise reactive species at the membrane surface and within it, which most antioxidants cannot do.
Unlike beta-carotene, it does not convert to vitamin A, so it carries none of the accumulation concerns that apply to preformed vitamin A. It also crosses into the retina and the brain, which other carotenoids largely do not.
In skin, it accumulates and appears to reduce the damage caused by ultraviolet exposure, which underpins the skin research. The endurance rationale rests on reduced oxidative damage to muscle during prolonged effort.
What the evidence shows
Skin research is the more consistent area, with trials reporting improvements in skin moisture, elasticity and resilience to ultraviolet exposure over 6 to 12 weeks.
Endurance findings are mixed. Some trials report improved cycling performance and reduced markers of muscle damage; others find no meaningful effect. Trial sizes are generally small and a fair proportion are industry-linked.
The same caveat that applies to other antioxidants applies here: reducing exercise-induced oxidative stress may blunt some of the adaptations training produces. That has been demonstrated more clearly for high-dose vitamin C and E than for astaxanthin, but the principle is worth weighing.
Dosing
Typical range is 4 to 12 mg daily. Skin research has generally used 4 to 6 mg; endurance trials often 4 to 12 mg.
Take with a fat-containing meal. Astaxanthin is fat-soluble and absorption without dietary fat is poor, which makes this more important than the exact dose.
Choose algal-derived rather than synthetic, and expect effects to accrue over 6 to 12 weeks rather than quickly. As with other antioxidants, consider whether to take it around training sessions if you are training specifically to drive adaptation.
Accumulates in tissue over weeks; effects reported over 6-12 weeks
Timing
With a fat-containing meal; allow 6-12 weeks
Competition status
Permitted — not on the WADA Prohibited List
Category
Endurance
Safety and side effects
Astaxanthin is well tolerated across the trial literature, with few adverse effects reported. Digestive upset is the occasional complaint.
At high doses some people notice a slight orange or reddish tint to the skin, which is harmless and resolves on reducing intake, similar to the effect from very high beta-carotene intake.
It may have mild effects on blood pressure and on how readily blood clots. Speak to your doctor before use if you take regular medication. Products derived from krill rather than algae carry shellfish allergen considerations.
Who should avoid it
Speak to your doctor before use if you take regular medication, particularly anything affecting blood pressure or clotting. Krill-derived products carry shellfish allergen declaration. Not established at supplemental doses in pregnancy or breastfeeding. Consider timing away from training if training for adaptation.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
