Astaxanthin is a red-orange carotenoid made by microalgae and passed up the food chain to salmon, trout, shrimp and krill. That's where salmon gets its color. In human trials it has mostly been tested at 4 to 12 mg a day for skin, eye comfort and exercise measures, and the results so far are small, short and often industry funded.
Astaxanthin gets called a "super antioxidant" a lot online. The real story is more interesting and a lot less certain. It's a pigment, it's in food you may already eat, and it has a decent safety record at the doses people take. It also had a moment in aging research in 2023, when a large mouse program reported longer lives in male mice, and then a follow-up study in 2026 didn't see that again. This guide walks through what astaxanthin is, where you find it, what human studies measured, and how to read a label if you're thinking about it.
Last reviewed: November 2, 2026
Key Takeaways
- Astaxanthin is a carotenoid, the same family as beta-carotene and lutein. Microalgae such as Haematococcus pluvialis make it, and seafood picks it up.
- Wild sockeye salmon has been measured at about 26 to 38 mg per kg of flesh, roughly 3 to 4 mg in a 100 g portion. Farmed Atlantic salmon has much less, about 6 to 8 mg per kg.
- Most human trials used 4 to 12 mg a day for 6 weeks to 4 months, looking at skin moisture, eye focusing and muscle measures in healthy people.
- In 2023 the US Interventions Testing Program reported a 12% longer median lifespan in male mice fed astaxanthin. A 2026 follow-up at different doses and start ages found no lifespan gain.
- A 2019 safety review of 87 human studies found no safety concerns with natural astaxanthin. Europe's food safety agency considers up to 8 mg a day from supplements safe for adults.
What is astaxanthin?
Astaxanthin is a fat-soluble pigment in the carotenoid family. Carotenoids are what make carrots orange and tomatoes red. Astaxanthin is the one that makes salmon flesh pink and cooked shrimp turn red.
Animals can't make it. A freshwater microalga called Haematococcus pluvialis produces it in large amounts when it's stressed by bright light or a lack of nutrients, turning from green to deep red. It can build up to about 3.8% of the alga's dry weight. Small crustaceans eat the algae, and fish eat the crustaceans. Some yeasts, such as Phaffia rhodozyma, also make it.
Chemically, astaxanthin is a xanthophyll, a carotenoid with oxygen in its structure. Its shape lets it sit across cell membranes, which is one reason researchers became interested in it as an antioxidant. In lab work it neutralizes reactive oxygen molecules well. Whether that translates into anything you'd notice in your body is a separate question, and that's what human trials try to answer.
Where does astaxanthin come from in food?
Seafood is the only meaningful food source. How much you get depends a lot on the type of fish and whether it was wild or farmed.
| Food | Astaxanthin reported | What that means per portion |
|---|---|---|
| Wild sockeye salmon | About 26 to 38 mg per kg of flesh | Roughly 2.6 to 3.8 mg in 100 g (3.5 oz) |
| Farmed Atlantic salmon | About 6 to 8 mg per kg of flesh | Roughly 0.6 to 0.8 mg in 100 g |
| Chum salmon (wild) | Low compared with sockeye | Well under 1 mg in 100 g |
| Large farmed trout | About 6 mg per kg (Europe) and 25 mg per kg (Japan) in market samples | Varies with the feed used |
| Shrimp, crab, krill | Present, amounts vary widely | Usually small per serving; krill oil products list it on the label |
The per-portion column is our own math from the per-kilogram figures in a 2014 review in Marine Drugs. Farmed fish get astaxanthin (natural or synthetic) added to their feed, which is why farmed salmon is still pink, just less so. A 2025 study by researchers in Colorado found wild salmon had more of the main natural form than farmed salmon, cooking didn't lower it much, and canned salmon had less.
So if you eat wild sockeye a couple of times a week, you're getting a few milligrams each time. That's in the same range as the lower trial doses, though spread out rather than daily. For the bigger picture on eating patterns, see our guide to diet and longevity.
What does the research say about astaxanthin benefits?
Search results for astaxanthin benefits tend to list a dozen things. Most of those come from cell and animal studies. Here's what human trials in healthy people actually measured.
| Study | Who and how long | Dose | What they found |
|---|---|---|---|
| Tominaga et al., 2017 | 65 healthy women, 16 weeks | 6 or 12 mg a day | Skin moisture and wrinkle scores got worse in the placebo group over a dry August to December stretch; they held steady with astaxanthin. Sponsored by an astaxanthin maker. |
| Ito et al., 2018 | 23 healthy adults, 10 weeks | 4 mg a day | Skin took a little more UV light before reddening, and lost less moisture after UV exposure. People rated their skin texture better. Sponsored by the maker. |
| Liu et al., 2018 | 42 adults aged 65 to 82, 4 months, with 3 months of walking training | 12 mg astaxanthin plus vitamin E (tocotrienol) and zinc | Both groups improved endurance with training. Leg muscle strength and size rose more in the supplement group. |
| Liu et al., 2021 | Same 42 adults, 3 months of training | Same formula | Muscle endurance improved only in the supplement group. Fat use during light exercise rose more, mainly in men. |
| Kizawa et al., 2021 | 44 adults with tired eyes from screen work, 6 weeks | Astaxanthin with anthocyanin and lutein | Better eye focusing response after screen work and fewer complaints about focusing than placebo. A combination product, so astaxanthin's own share is unknown. |
A few things stand out. The groups are small, usually 20 to 65 people. Many trials were paid for by companies that sell astaxanthin. The outcomes are measurements in healthy people, like skin moisture or how far someone can walk, not long-term health outcomes. And two of the muscle studies used a mixed formula, so you can't credit astaxanthin alone.
None of that makes the results fake. It means they're early. If you see astaxanthin sold as a cure-all, that's marketing running far ahead of the data.
Does astaxanthin help you live longer?
Nobody knows, and the mouse data has gotten more complicated, not less.
The Interventions Testing Program, funded by the US National Institute on Aging, tests compounds in genetically mixed mice at three sites at once. In its 2023 report, astaxanthin fed from 12 months of age raised median lifespan in male mice by 12%. Females didn't live longer. The diet contained a lot of astaxanthin, about 1,840 parts per million, far beyond anything a person would eat. One supplier of the compound was involved in the study, which the authors disclosed.
In 2026 the same program tested astaxanthin again at different doses and later start ages. This time it didn't extend lifespan in either sex. The authors wrote that timing and dose seem to matter a lot, and that single findings in aging research need repeat testing before anyone leans on them.
That's a useful lesson for anyone reading longevity headlines. The first result was real data, and it still didn't hold up once the dose and start age changed. Our explainers on healthspan vs lifespan and senescent cells cover why mouse lifespan results so often fail to carry over to people.
How much astaxanthin do people take?
There's no official daily intake, because astaxanthin isn't an essential nutrient. What we have are trial doses and safety limits.
| Reference point | Amount | Source |
|---|---|---|
| Common trial doses | 4 to 12 mg a day | Trials in the table above |
| Doses approved or recommended in different countries | 2 to 24 mg a day | Brendler and Williamson, 2019 review |
| European Food Safety Authority, supplements | Up to 8 mg a day judged safe for adults, on top of diet | EFSA, 2020 |
| Wild sockeye salmon | About 3 to 4 mg per 100 g portion | Our math from the 2014 review |
EFSA's 2020 opinion did not extend that 8 mg conclusion to teenagers or children, because the total from food and supplements could exceed its safe intake level for those ages. So astaxanthin supplements are an adult product.
Because it's fat-soluble, astaxanthin is usually taken with a meal that has some fat in it. Most supplements suspend it in oil inside a softgel.
Is there a downside to taking astaxanthin?
The safety picture is reassuring so far. In their 2019 review, Brendler and Williamson looked at 87 human studies of natural astaxanthin, 35 of them at 12 mg a day or more, and found no safety concerns. They also noted that much of the cautious regulatory math was based on synthetic astaxanthin, which is chemically different from the natural form.
Still, a few points are worth knowing:
- Long-term data is thin. Most trials ran weeks to a few months.
- Medications. Interaction studies in people are scarce. If you take prescription medicine, ask your pharmacist or doctor before adding it, as you would with any supplement.
- Pregnancy and breastfeeding. There isn't enough research, so talk to your clinician first.
- Allergies. Krill-based products come from shellfish. Algae-based products don't.
Algae, krill or synthetic: how to read an astaxanthin label
If you're comparing products, the label tells you more than the front of the bottle. Our guide to reading a Supplement Facts label covers the basics. For astaxanthin specifically, look for:
- The milligrams of astaxanthin itself. Some labels list the weight of the algae extract, such as "100 mg Haematococcus pluvialis extract," which isn't the same as 100 mg of astaxanthin. You want the astaxanthin number.
- The source. Haematococcus pluvialis is the natural algae source used in most human trials. Krill oil contains astaxanthin too, usually in small amounts. Synthetic astaxanthin is mostly used in fish feed.
- The carrier oil. Softgels typically use olive, safflower or sunflower oil. That's normal.
- Third-party seals. If a product claims testing, check which organization and what was tested.
One thing people mix up: regular fish oil isn't an astaxanthin source. Fish oil is purified for omega-3 fats, and the pigment isn't part of that. Our own OPA Omega-3 Fish Oil Gummies, for example, provide fish oil with EPA and DHA and don't contain astaxanthin. If you want both, they're separate products or a krill oil, and you'd read each label on its own.
How does astaxanthin compare with other antioxidants?
You'll often read that astaxanthin is "6,000 times stronger than vitamin C." That number comes from test-tube measurements of one type of chemical reaction. It doesn't tell you what happens in a person, where absorption, storage and the body's own antioxidant systems all matter.
Researchers have mostly moved away from thinking of antioxidants as a single scale you can rank. Some compounds, like astaxanthin, are studied for how they sit in cell membranes and affect signaling. Others, like the compounds in our guides to mitochondrial health and CoQ10, are studied for specific roles in energy production. Bigger isn't automatically better.
Frequently asked questions
What foods contain astaxanthin?
Wild salmon, especially sockeye, has the most, at roughly 3 to 4 mg per 100 g. Farmed salmon, trout, shrimp, crab, lobster and krill contain smaller and more variable amounts. Plant foods don't contain it, apart from the microalgae that make it.
Is astaxanthin safe to take every day?
Trials have used daily doses of 4 to 12 mg for up to several months without safety concerns, and a 2019 review of 87 human studies found none. EFSA considers up to 8 mg a day from supplements safe for adults. Long-term data beyond a few months is limited.
What does astaxanthin do for your face?
In two small Japanese trials, people taking 4 to 12 mg a day kept more skin moisture during a dry season or after UV exposure than people on placebo. Both trials were funded by makers of astaxanthin. Taking it isn't a replacement for sunscreen.
What not to mix with astaxanthin?
There's little direct research on interactions. Because evidence is limited, check with a pharmacist or doctor if you take prescription medicine, are pregnant or breastfeeding, or plan to combine several antioxidant supplements.
Is astaxanthin the same as krill oil?
No. Krill oil is an omega-3 oil that naturally contains some astaxanthin, usually a small amount. Astaxanthin supplements are usually made from algae and provide a set number of milligrams per softgel.
When is the best time to take astaxanthin?
It's fat-soluble, so most people take it with a meal that contains some fat. The time of day hasn't been shown to matter.
Sources
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- Lu P, Reisdorph N, Hendricks AE, et al. Characterization of astaxanthin isomers in different types of salmon filets and human plasma after salmon consumption. Food Chem. 2025;482:144024. PubMed 40179560
- Tominaga K, Hongo N, Fujishita M, Takahashi Y, Adachi Y. Protective effects of astaxanthin on skin deterioration. J Clin Biochem Nutr. 2017;61(1):33-39. PubMed 28751807
- Ito N, Seki S, Ueda F. The protective role of astaxanthin for UV-induced skin deterioration in healthy people: a randomized, double-blind, placebo-controlled trial. Nutrients. 2018;10(7):817. PubMed 29941810
- Liu SZ, Ali AS, Campbell MD, et al. Building strength, endurance, and mobility using an astaxanthin formulation with functional training in elderly. J Cachexia Sarcopenia Muscle. 2018;9(5):826-833. PubMed 30259703
- Liu SZ, Valencia AP, VanDoren MP, et al. Astaxanthin supplementation enhances metabolic adaptation with aerobic training in the elderly. Physiol Rep. 2021;9(11):e14887. PubMed 34110707
- Kizawa Y, Sekikawa T, Kageyama M, et al. Effects of anthocyanin, astaxanthin, and lutein on eye functions: a randomized, double-blind, placebo-controlled study. J Clin Biochem Nutr. 2021;69(1):77-90. PubMed 34376917
- Harrison DE, Strong R, Reifsnyder P, et al. Astaxanthin and meclizine extend lifespan in UM-HET3 male mice. GeroScience. 2024;46(1):795-816. PubMed 38041783
- Korstanje R, Strong R, Salmon AB, et al. Astaxanthin, meclizine, mitoglitazone, pioglitazone, alpha-ketoglutarate, mifepristone, methotrexate, and atorvastatin-telmisartan do not increase lifespan in UM-HET3 mice. GeroScience. 2026;48(3):3821-3830. PubMed 41843349
- Brendler T, Williamson EM. Astaxanthin: how much is too much? A safety review. Phytother Res. 2019;33(12):3090-3111. PubMed 31788888
- EFSA Panel on Nutrition, Novel Foods and Food Allergens (Turck D, et al.). Safety of astaxanthin for its use as a novel food in food supplements. EFSA J. 2020;18(2):e05993. PubMed 32874213
Disclosure: OPA Nutrition sells supplements, including products mentioned in this article. This content is for education only and is not medical advice. Statements about dietary supplements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. Talk to your healthcare provider before using any supplement, especially if you take medication or have a medical condition.
