What is astaxanthin?

I came across astaxanthin in May 2012 while continuing my research into antioxidants. What is astaxanthin? And why have I not heard of it before?

So, I absolutely had to look into it in more detail, and read the studies and reviews completed up to date, as of June 2012, and, most importantly, research how astaxanthin affects glutathione activity.

It appears that it is a relatively unknown dietary supplement with potent antioxidant capabilities, and it is rapidly becoming more “famous”.

Astaxanthin is a carotenoid and a powerful antioxidant. Our bodies do not synthesize astaxanthin, so it can only be obtained from food or supplementation. Astaxanthin does not convert into vitamin A – good news, because it means that supplementation will not lead to vitamin A overdose and toxicity.

flamingo Where can this antioxidant be found in nature? Astaxanthin is present in microalgae, fungi, plankton, yeast, and seafood - salmon, trout, krill, shrimp, crabs, lobsters - to all of which astaxanthin gives their distinct pink or red-orange hues.

It also adds color to the feathers of birds – flamingos and quail. It is from astaxanthin in their food that these fish, sea creatures and birds pick up their special coloring.

Natural supplemental astaxanthin is manufactured predominantly from microalgae Haematoccocus pruvialis.

This algae produces a certain astaxanthin isomer that is the same as the form found in wild salmon and thus most commonly consumed by humans. This source of astaxanthin appears to be the most desirable when choosing a supplement. Our bodies know how to metabolize nutrients from salmon much better than from plankton or feathers. Other sources of natural supplemental astaxanthin may be krill, shrimp and yeast.

Synthetic astaxanthin has also been developed. It is chemically derived and not advisable as a source of supplemental astaxanthin. There is a debate that the synthetic form may yield different results in clinical trials than the natural form, so scientists are not sure yet which form to prefer in their research. Studies done so far have used primarily the natural form of astaxanthin; however, at least one study I came across had used the synthetic form along with the natural form.

salmon Since the diet of farm raised salmon (and other seafood) is poor and results in white flesh, synthetic astaxanthin is fed to fish in order to improve the color and make the end product more appealing to consumers. For this reason you should always choose wild caught fish and seafood.

Dosages of astaxanthin used in human trials varied from 1 mg to 100 mg taken either once, or daily over a period of several weeks up to a year, without any adverse reactions or side effects.

Supplemental astaxanthin usually comes in 4 mg, 6 mg and 12 mg capsules to be taken once a day with a meal. And positive health results may be observed at doses as little as 4 mg after 2-6 weeks.

Clinical studies have proven that supplemental astaxanthin is readily absorbed into the blood from the intestines and crosses blood-brain barrier. Astaxanthin plasma elimination half-life was assessed at 52 (+/- 40) hours (how fast it is eliminated from blood after a person stops taking a supplement).


In vitro and in vivo studies have shown that astaxanthin is a very potent scavenger of free radicals. It disrupts oxidant chain reactions and quenches dangerous reactive oxygen and nitrogen molecules.

Because of a molecular structure that is different than that of other carotenoid antioxidants (beta- and alpha-carotene, lycopene, lutein and zeaxanthin), astaxanthin is a more powerful antioxidant. Its uniqueness lies in its ability to neutralize free radicals both outside and inside a cell preserving cell membrane. For this reason dietary supplementation with astaxanthin has a strong potential to provide much better antioxidant protection of a cell than other carotenoids.

Review “Astaxanthin: a potential therapeutic agent in cardiovascular disease”, Fassett RG, Coombes JS., Marine Drugs 2011 Mar 21;9(3):447-65 states that astaxanthin is a potent antioxidant with anti-inflammatory properties and as such has potential as a therapeutic agent in atherosclerotic cardiovascular disease.

Astaxanthin is a fat-soluble antioxidant. That is why astaxanthin supplement should be taken with a meal that contains fat or a quality fish oil supplement. In fact, research has shown that astaxanthin + fish oil combo exhibits even more powerful antioxidant and immuno-enhancing action. This could be due to the fact that they are found in fish together and work in synergy.

To learn how astaxanthin affects glutathione activity visit our page Astaxanthin and Glutathione.


Preliminary research into astaxanthin shows very promising results. Most of the studies showing astaxanthin benefit in a wide range of conditions were performed either on cultured cells or animals (mice, rats, and dogs) using very high doses of supplemental astaxanthin. This scientific research indicates the following health benefits of supplemental astaxanthin:

  • it reduces lipid peroxidation (oxidation of fats)

  • it reduces the biomarkers of oxidative stress and inflammation in mice

  • its antioxidative activity reduces the oxidative stress on the kidneys and prevented renal cell damage in diabetic mice

  • it lowers level of blood glucose in diabetic mice

  • it significantly reduces blood pressure in rats

  • it inhibits the growth of mammary (breast cancer) tumors in mice

  • it protects the myocardium when administered both orally or intravenously prior to the induction of the ischemic event in mice

  • it reduces incidence of secondary thrombosis in a canine model

  • it exhibits protective effect on the retina in rats with elevated intraocular pressure (glaucoma)

  • it improves immune response in rats when administered in combination with fish oil

  • it increases endurance, increases fat utilization and prolongs exercise time in mice

  • it proves to be a potent agent against neurodegenerative disorder in cells due to its antioxidative and anti-inflammatory protection

  • it has good therapeutic effect on acetic acid-induced gastric ulcer in rats

  • it protects against liver damage in rats induced by CCl4 (carcinogenic chemical solvent) by inhibiting lipid peroxidation and stimulating the cellular antioxidant system

  • it protects against UVA-induced DNA alterations in human skin and intestinal cells

  • it has protective effect against oxidative impairment and DNA damage induced by 60Co gamma-rays in mice

Human trials

Such exciting results in animal studies sparked interest in researching astaxanthin benefits in human subjects. Human studies have proven bioavailability of astaxanthin, its ability to be absorbed in bloodstream and to cross blood-brain barrier.

Human trials showed the following benefits of supplemental astaxanthin:

  • it improves erythrocyte antioxidant status and decreased Phospholipid hydroperoxides (PLOOH) levels (elevated in dementia), which may contribute to the prevention of dementia

  • it decreases oxidation of fatty acids

  • it reduces oxidation of low-density lipoprotein (LDL or “bad” cholesterol)

  • it decreases triglycerides (at 12 and 18 mg/day) and increases high-density lipoprotein (HDL or “good” cholesterol) at 6 and 12 mg/day, for 12 weeks

  • it improves central retinal dysfunction in age-related macular degeneration when taken with other antioxidants (vitamins C and E, lutein and zeaxanthin)

  • it decreases whole blood transit time (improves blood flow)

  • it lowers C-reactive protein (CRP) levels which is a protein in blood and a marker of inflammation, at a dose of 2 mg/day for four weeks in healthy participants

  • it significantly reduces oxidative stress, hyperlipidemia and biomarkers of inflammation in patients with reflux esophagitis (heartburn)

  • it decreases gastric inflammation in Helicobacter pylori-positive patients, at 40 mg/day

  • it increases power output and improves 20 km cycling trial time performance in competitive cyclists, at a dose of 4 mg/day for four weeks

  • it prevents UV-induced skin damage as a component of topical liposomal formulation

No side effects were reported in any of the human trials.

Search for “astaxanthin” at pubmed.org returned 909 articles as of 6/6/2012, and more studies are being added all the time. The research into the benefits of this antioxidant is ongoing. I will do my best to keep the information updated. The studies I reviewed while preparing this page can be accessed here.

This amount of research proves that astaxanthin is an important and powerful antioxidant with anti-inflammatory and cell membrane protective qualities.

Sufficient quantities of astaxanthin, comparable with the doses used in human trials, cannot be obtained from consumption of salmon and/or other seafood. Dietary supplementation with natural astaxanthin should be considered and discussed with your physician in order to benefit from this carotenoid antioxidant.

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