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Astaxanthin is a red pigment found in fish, shrimp, and some microalgae. It is a potent antioxidant that has been proven to help with cardiovascular risks, protect the brain, and modulation the immune system. Read this post to learn more about the proven benefits of astaxanthin and how it can help optimize your health.


Astaxanthin (ASTA) is a naturally-occurring orange-red pigment carotenoid found in algae, shrimp, lobster, crab, and salmon.

Astaxanthin is made by the green microalgae Haematococcus pluvialis, Chlorella zofingiensis, Chlorococcum, and yeast Phaffia rhodozyma (R).

The green algae H. pluvialis makes high amounts of astaxanthin when its condition is unfavorable, including high UV exposure, which is why astaxanthin has strong antioxidative properties (R).

Animals that eat these microalgae or yeast then absorb astaxanthin into their bodies, which is why wild shrimp, lobster, crab, and salmon have bright red-orange colors (R).

Wild salmon can have up to 26 – 38 mg of astaxanthin per kg of body weight, whereas farmed Atlantic salmons typically have 6 – 8 mg of astaxanthin per kg of body weight (R).

Astaxanthin is not converted to vitamin A in the human body.

Like other carotenoids, astaxanthin has self-limited absorption orally and no toxicity was detected when tested at very high doses (up to 465 mg/kg/day for male and 557 mg/kg/day for female) in rats (R, R2).

However, overconsumption of astaxanthin can turn animal skin and tissues red, which is why astaxanthin is used in feed for farmed seafood and fish (R).

Pharmacokinetics of Astaxanthin

Astaxanthin is a highly fat-soluble substance, which means that it is better absorbed when consumed with oil (R).

When astaxanthin is ingested, it is digested and absorbed in a similar manner as fat, which means it is assembled into chylomicrons. The chylomicrons are absorbed into lymph circulation before remnants of astaxanthin are digested by lipoprotein lipases. Astaxanthin is then assimilated into lipoprotein particles to get transported into tissues (R).

This means astaxanthin can more readily affect the metabolism of fat and cholesterol, especially when it relates to cardiovascular health.

Ingested astaxanthin is metabolized by first-pass liver metabolism primarily by liver CYP450 in rats (R).

Astaxanthin is found in all tissues studied, except for the heart (R).

Astaxanthin as a Potent Antioxidant

As an antioxidant, astaxanthin is 10 times stronger than zeaxanthin, lutein and beta-carotene, and 100 times stronger than vitamin E (R, R2).

The structure of astaxanthin allows it to span across cell membranes or stay outside of cell membranes, allowing it to protect cell membranes from both inside and outside the cell (R).

1) Astaxanthin Mitigates Oxidative Effects of Diabetes

Generally, high blood sugar causes high levels of oxidative stress in diabetic patients. Astaxanthin can protect pancreatic β-cells (which produce insulin) from oxidative stress caused by high blood sugar (R).

It is also a good agent in the recovery of lymph cell dysfunctions associated with diabetic rats (R).

It also prevents diabetic nerve disorder by reduction of the oxidative stress and renal cell damage (R).

The carotenoid showed a protective effect on high glucose-induced oxidative stress, inflammation, and apoptosis in proximal tubular epithelial cells (R).

Astaxanthin improves insulin sensitivity in rats and mice on high fat and high fructose diets (R, R2).

2) Astaxanthin Reduces Risks of Cardiovascular Disease

Astaxanthin can reduce LDL cholesterol, increase HDL cholesterol and adiponectin, and prevent lipid oxidation in the blood vessels (R, R2, R3, R4).

In a mouse model, astaxanthin delays and reduces blood clotting in the blood vessels, and increases blood flow (R).

3) Astaxanthin Reduces Heart Damage from Heart Attacks

In rats, rabbits, and dogs heart attack models, pre-treatment of the animals with a synthetic astaxanthin reduce the damage on the heart that was caused by the heart attacks in a dose-dependent manner (R, R2, R3).

4) Astaxanthin Helps with Non-Alcoholic Fatty Liver Disease

Astaxanthin improves insulin sensitivity, liver inflammation, and reduces fatty liver in mice on a high-fat diet. In addition, astaxanthin helps with fatty liver in humans comparing to placebo (R).

5) Astaxanthin Inhibits Cancer

In rats and mice with chemical-induced oral, bladder, colon, and breast cancers, astaxanthin inhibits tumor formation and growth (R, R2, R3, R4).

Astaxanthin inhibits chemical-induced fibrosarcoma by activating the anti-cancer immune system (R).

In cell cultures, astaxanthin inhibits the growth of colon, fibrosarcoma, breast, and prostate cancer cells and embryonic fibroblasts, with activation of tumor-suppressor genes such as p53 (R).

6) Astaxanthin Modulates the Immune Responses

Combined astaxanthin and fish oil supplementation modulate lymphocyte function in rats (R).

Astaxanthin enhanced antibody production and decreased immune response in older animals after dietary supplementation (R).

Supplementation with 2 mg astaxanthin for 8 weeks enhanced immune response and reduced CRP in young healthy females (R).

7) Astaxanthin Protects the Stomach Lining from H. pylori and Ulcers

Mice pretreated with astaxanthin for 1 hour before ulcer induction had significantly decreased gastric ulcers. These results suggest that astaxanthin has antioxidant properties and exerts a protective effect against ulcer formation in murine models (R).

Cell extracts of Haematococcus and Chlorococcum significantly reduced the number of H. pylori (a bacteria that causes stomach ulcer) and stomach inflammation in H. pylori-infected mice (R, R2).

8) Astaxanthin Protects Against UV Damage

It can prevent skin thickening and reduce collagen reduction against UV-induced skin damage (R, R2).

Astaxanthin protects against UVA-induced skin photoaging such as sagging and wrinkles (R).

9) Astaxanthin Reduces Exercise Fatigue

Antioxidant effects of astaxanthin can significantly delay exhaustion in a forced swimming test in rats (R).

10) Astaxanthin Protects the Mitochondria from Oxidative Stress

Astaxanthin is effective at improving mitochondrial function by protecting the mitochondria from oxidative stress (R).

Dietary astaxanthin improves mitochondrial function in white blood cells of dogs, most likely by alleviating oxidative damage to DNA and proteins (R).

Astaxanthin Protects the Nervous System

11) Astaxanthin Reduces Brain Damages from Stroke

Pre-treatment with high dose (80 mg/kg) astaxanthin significantly reduced brain damage from a stroke in rats (R).

Mice pre-treated with astaxanthin performs better than mice that were not treated with astaxanthin in a learning performance test after a stroke (R).

12) Astaxanthin Helps Recovery from Traumatic Brain Injury

Astaxanthin reduces brain swelling after a traumatic brain injury in mice (R).

Astaxanthin appears to help speed physical recovery from a traumatic brain injury in mice, albeit with no effects on cognitive function (R).

13) Astaxanthin May Protect Against Alzheimer’s Disease

In a cell model, astaxanthin protects neuronal cells from beta-amyloid-induced toxicity, suggesting that astaxanthin may protect against Alzheimer’s Disease (R).

Astaxanthin protects hippocampal neurons against the effects of beta-amyloid toxicity (R).

Astaxanthin combats brain aging in rats by increasing BDNF levels (R).

The effects of astaxanthin on the aging brain differ between genders in rats (R).

14) Astaxanthin may Protect Against and Treat Parkinson’s Disease

Due to its anti-inflammatory, antioxidant, and mitochondrial protective effects, astaxanthin has been proposed as a potential therapeutic agent for Parkinson’s Disease (R).


15) Astaxanthin Protects the Eyes from Bacterial Inflammation

Astaxanthin protects the rat eyes inflamed by bacterial toxins by reducing inflammation (R, R2).

16) Astaxanthin Helps with High Blood Pressure

Dietary astaxanthin helps with high blood pressure in many different ways, including by modulating nitric oxide and relaxes the blood vessel, thus helping with high blood pressure (R, R2).


Beneficial results have been observed at 2 mg in humans with dose-dependent effects at 8 mg (R).

Currently, no toxicity is found at very high doses (over 500 mg/kg of body weight) in mice (R, R2).

Side Effects and Warnings

Currently, there is no direct evidence demonstrating the harm of using astaxanthin in humans or animals.

While there is no large-scale study to demonstrate long-term safety or harmful effects of astaxanthin in humans, several such studies have demonstrated conclusively that long-term supplementation of similar antioxidants including carotenoids and lutein increases the risks of cancer, especially among smokers (R, R).


  • ASTA is a member of the xanthophylls, because it contains not only carbon and hydrogen but also oxygen atoms ((R).
  • However, synthesis of ASTA is not possible in humans. This also means that excess intake will not cause vitamin A toxicity (R).
  • ASTA and canthaxanthin are scavengers of free radicals, chain-breaking antioxidants and potent quenchers of reactive oxygen and nitrogen species including singlet oxygen, single and two electron oxidants (R).
  • ASTA inhibits NF-κB and Wnt signaling by downregulating the key regulatory enzymes IKKβ and GSK-3β. Analysis of gene expression and docking interactions reveals that inhibition of these pathways is mediated via inactivation of the upstream signaling kinases Erk/Akt by ASTA (R).
  • Additionally, ASTA induced caspase-mediated mitochondrial apoptosis by downregulating the expression of antiapoptotic Bcl-2, p-Bad, and survivin and upregulation of proapoptotic BASTA and Bad, accompanied by efflux of Smac/Diablo and cytochrome-c into the cytosol and induced cleavage of poly (ADP-ribose) polymerase (PARP) (R).
  • ASTA, as well as its esters, showed 80% anti-lipid peroxidation activity in ethanol-induced gastric ulcer and skin cancer in rats (R).
  • Astaxanthin has been shown to induce expression of Nrf2 and its downstream antioxidant-related genes including SOD, GPx, and UCP-2 in mouse liver (R).
  • Adding H. pluvialis extract to cell cultures of many cancer cell lines and a fibroblast cell line inhibit cell growth while upregulating p53, p21(WAF-1/CIP-1), and p27 expression. At the same time, apoptotic and inflammatory genes were upregulated (R).
  • Astaxanthin supplementation (2 mg) decreases plasma CRP, but with no difference in TNF and IL-2 concentration, while plasma IFN-gamma and IL-6 increases in subjects given 8 mg of astaxanthin (R).
  • Astaxanthin protects eyes against bacterial LPS by suppressing NO, PGE2, and TNF-alpha by directly blocking NOS activity and inhibiting NF-kB signaling in rats (R, R2).

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  • peter

    Key question: how is going together sulforan with astaxanthin? Sulforan may cause Dna isntability,meanwhile working as a Dna methiltransferase-inhibitor… and astax try to protect the cell includes Dna…. well, is it clever to use together, or NOT???

  • Harry

    Not true Nattha,
    Liao KS, Wei CL, Chen JC, et al. Astaxanthin enhances pemetrexed-induced cytotoxicity by downregulation of thymidylate synthase expression in human lung cancer cells. Regul Toxicol Pharmacol. 2016;81:353-61.

    Ko JC, Chen JC, Wang TJ, et al. Astaxanthin down-regulates Rad51 expression via inactivation of AKT kinase to enhance mitomycin C-induced cytotoxicity in human non-small cell lung cancer cells. Biochem Pharmacol. 2016;105:91-100.

    Have a look at these to studies that show it reduces chances of lung cancer, there are studies now emerging stating its benefits on oral cancer, liver and prostate cancer. Ofcourse no longterm studies conducted. Just like with beta-carotene scientifical studies are mixed it does raise the alarm on the pharmaceutical industry (supplements vs medicine). Then again large amounts of anything cant be good and we dont know what is considered safe with astaxanthin

    As a PHD student I would have expected you to know better. Anyways its worth researching in to it and perhaps re-write or make a new article. if you need any more studies I can send them to you.

  • Patrick

    Astaxanthin is a DHT blocker. The combination of Astaxanthin and saw palmetto has shown to work comparably to certain anti-balding medication. People like Chris Walker of Anabolic Men talk about this. It is one of the most famous DHT blockers. Consequently, I’m surprised that it was not mentioned here. In fact, I came here because I’m a huge fan of krill oil but this DHT issue has long concerned me. I was hoped for unique professionalism and insight SelfHacked often offers, on this particular issue of Astaxanthin and DHT. Unfortunately, there is no such insight. Otherwise a good article.

  • canineeleven

    “Side Effects and Warnings

    Currently, there is no direct evidence demonstrating the harm of using astaxanthin in humans or animals.

    While there is no large-scale study to demonstrate long term safety or harmful effects of astaxanthin in humans, several such studies have demonstrated conclusively that long term supplementation of similar antioxidants including carotenoids and lutein increases the risks of cancer, especially among smokers…”

    NOT TRUE to Astaxantin!….neither ASTA never transform to beta-carotinoid, nor zaexatin and lutein!
    Big dose beta -carotinoid is the danger in the mentioned case.
    That’s why ASTA is SAFE!

    1. Nattha Wannissorn, PhD

      It doesn’t transform, but it’s a very similar substance that’s what it’s saying. It’s a reasonable hypothesis to say that because the molecular structures are very similar, it MIGHT do the same thing. The paragraphs stated the FACT that there is no evidence. There is no evidence that ASTA is 100% safe and lack of proof isn’t proof against. Not to be a scare tactic but something to keep in mind not to use it long term.

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