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What is Astaxanthin?

Astaxanthin is a carotenoid created by micro-algae (Haematococcus pluvialis) in times of stress. When the Haematococcus pluvialis algae are exposed to change in their environment such as direct sunlight, starved of food or being eaten, it produces astaxanthin to protect itself. As a potent antioxidant, astaxanthin protects the algae from free radicals and oxidative stress, keeping it alive and well when stressed. This carotenoid is what gives many sea creatures such as salmon, krill, and crayfish their red colour. Unlike many other antioxidant supplements, astaxanthin does not develop into a pro-oxidant once exhausted.

What is it used for?

Traditional/Ethnobotanical uses

Astaxanthin has been consumed in seafood in small doses throughout history but only recently have we been able to reap the benefits through high dose supplementation.

Astaxanthin concentrations:

  • Krill - 120 PPM (part per million)
  • Shrimp - 1,200 PPM
  • Phaffia yeast - 10,000 PPM
  • Haematococcus pluvialis - 40,000 PPM
General Uses

Natural astaxanthin is sold all around the world as a natural antioxidant supplement. Exceeding the antioxidant power of the well-researched lutein and zeaxanthin, astaxanthin has been claimed to aid eye health, support heart health, improve skin quality and reduce inflammation throughout the body.

As the discovery of astaxanthin for human benefit is relatively new, the majority of trials have been conducted on animals with human research growing.

What is the recommended dosage?

Recommended dosages range from 4mg-12mg a day depending on the desired effect. 4mg daily has been shown to have positive effects reducing inflammation but up to 12mg a day provides more of a therapeutic dose for those in need of higher levels of antioxidants.

Astaxanthin is a fat-soluble carotenoid that should be with a meal containing fat for optimal absorption.

How safe is it?


Antioxidant supplements have exhibited a positive correlation with fertility however this product is not recommended during pregnancy or breastfeeding due to lack of safety studies in these areas.


No well-documented interactions have been identified apart from a potential to interact with hormone altering drugs such as a 5-alpha-reductase inhibitor.

Side Effects

With extreme doses (48mg daily) feces may turn a reddish hue due to the red pigmentation of astaxanthin.


Doses of up to 50mg have been tolerated. An upper toxicity limit is not known. Note not all astaxanthin is biosynthesized by living microalgae. Synthetic astaxanthin made in laboratories from petrochemicals has not been approved for human consumption.

Where to buy?

Astaxanthin is available from Biosphere Nutrition.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.