Astaxanthin
A carotenoid antioxidant from microalgae that's 6,000x more potent than vitamin C. Protects your skin from UV damage, supports eye health, and accelerates exercise recovery.
Astaxanthin is a red pigment produced by the microalgae Haematococcus pluvialis — it's what makes salmon and shrimp pink. It's one of the most potent natural antioxidants known, with unique ability to span the entire cell membrane and neutralise free radicals on both sides simultaneously.
Good for you if: You spend time in the sun, want to protect your skin from inside out, deal with eye strain, or want better exercise recovery and reduced inflammation.
Dive deeper into the researchCommon side effects
- Slight reddish tint to skin at very high doses
- Mild stomach upset without food
- May lower blood pressure slightly
What does astaxanthin do?
Most antioxidants can only work on one side of the cell membrane — either inside or outside. Astaxanthin is unusual because its molecular structure spans the entire membrane, neutralising free radicals on both the inner and outer surfaces simultaneously. This makes it exceptionally effective at protecting cells from oxidative damage.
It also crosses the blood-brain barrier and the blood-retinal barrier, giving it direct access to protect your brain and eyes — something most carotenoids can't do.
What can you expect?
- Better skin — increased UV resistance, less wrinkles, improved elasticity and moisture
- Reduced eye fatigue — especially helpful for screen-heavy work
- Faster recovery — reduced muscle soreness and oxidative stress after exercise
- Joint comfort — anti-inflammatory effects comparable to low-dose NSAIDs
- Cardiovascular support — improves lipid profiles and reduces arterial oxidative stress
How to take it
4–12 mg per day with a fat-containing meal. Start at 4 mg and increase to 8–12 mg if you want stronger skin protection or exercise recovery.
Natural astaxanthin from Haematococcus pluvialis is the only form worth buying. Synthetic astaxanthin is 20–50x less potent. Look for AstaReal or AstaZine branded ingredients.
Timing: Take with breakfast or lunch — a meal with healthy fats (eggs, avocado, olive oil) significantly improves absorption since astaxanthin is fat-soluble.
Track your inflammation markers alongside astaxanthin
eterni logs your hsCRP, oxidative stress markers, and supplement stack — so you can see if astaxanthin is making a measurable difference.
Get early accessFrequently Asked Questions
How much astaxanthin is in salmon?
Wild salmon contains about 3–4 mg of astaxanthin per 170g serving. Farmed salmon uses synthetic astaxanthin in feed, which is far less bioactive. To get a therapeutic dose (8–12 mg), you would need to eat about 500g of wild salmon daily — supplementation is more practical.
Is astaxanthin a blood thinner?
Astaxanthin has mild anti-platelet properties at higher doses (above 12 mg), but this effect is much weaker than aspirin or prescription blood thinners. At standard doses of 4–12 mg, it is not clinically significant for most people. If you are on anticoagulants, mention it to your doctor.
Can astaxanthin replace sunscreen?
No. Astaxanthin provides internal UV protection — reducing sunburn severity and improving skin repair — but it is not a substitute for topical sunscreen. Think of it as an additional layer of protection from inside. Studies show it can increase the time before UV-induced redness by about 20–30%.
Natural vs synthetic astaxanthin — does it matter?
Absolutely. Natural astaxanthin from H. pluvialis is predominantly the 3S,3'S stereoisomer and is esterified, giving it 20–50x greater antioxidant activity than synthetic astaxanthin (used in aquaculture feed). Always choose natural algae-derived products.
How it works in your body
Astaxanthin's molecular structure features hydroxyl and keto groups on each end of a polyene chain. This allows it to embed within cell membranes, spanning the entire lipid bilayer. It quenches singlet oxygen (the most reactive form of oxidative damage) 6,000x more effectively than vitamin C and 550x more than vitamin E.
Beyond direct antioxidant activity, astaxanthin activates the Nrf2 pathway — your body's master antioxidant switch — upregulating production of glutathione, superoxide dismutase, and catalase. It also inhibits NF-kB, reducing inflammatory gene expression.
What the studies show
- Skin: 6 mg/day for 6–8 weeks reduced wrinkle depth, improved elasticity, and increased skin moisture in multiple RCTs
- Eyes: 6–12 mg/day reduced eye fatigue, improved accommodation, and increased retinal blood flow
- Exercise: 12 mg/day reduced CK and CRP markers after intense exercise, with improved endurance performance
- Cardiovascular: 8–12 mg/day improved HDL, reduced oxidised LDL, and improved arterial elasticity
Side effects & safety
Astaxanthin has an excellent safety profile with no significant adverse effects in human trials:
- Skin colour — At very high doses (40+ mg), astaxanthin can cause a mild reddish tint to palms, similar to carotenodermia. Harmless and reversible.
- GI upset — Mild stomach discomfort if taken without food. Always take with a fat-containing meal.
- Blood pressure — May lower blood pressure slightly. If you're on antihypertensives, monitor.
- Hormonal — May inhibit 5-alpha reductase mildly, reducing DHT conversion. Generally considered a benefit.
Who should be cautious: People on blood thinners (mild anti-platelet effect), those with very low blood pressure, and anyone allergic to seafood if using krill-derived astaxanthin (algae-derived is fine).
Which labs to check
- hsCRP — tracks systemic inflammation
- Oxidised LDL — if available, a direct marker of oxidative damage astaxanthin targets
- Lipid panel — HDL, LDL, triglycerides
Know what's working. Know what's not.
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