Astaxanthin
Also sold as: Algal astaxanthin · Haematococcus pluvialis carotenoid
A lipid-soluble carotenoid marketed for skin, eye comfort and antioxidant support. Human studies mostly measure symptoms or biomarkers rather than lifespan or disease prevention.
Energy Focus Longevity
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Research
- Focus: Small combination-product cognition studies cannot isolate astaxanthin.
- Energy: Exercise-recovery biomarker findings are mixed and do not establish a reliable performance benefit.
- Longevity: Animal longevity findings do not establish longer human life.
REALITY CHECK // Small trials suggest skin or eye-comfort effects and modest antioxidant biomarker changes. Combination products, manufacturer links and null trials limit confidence; no human lifespan benefit or sunscreen replacement is established.
Levels: how we grade evidence. Grey = evidence of no benefit; amber = evidence it makes this goal worse.
Ratings are self-reported by a self-selected group of users: how it felt, not proof that it works.
Check your bottle
Compare what your label says with what was used in trials. This is a trial range, not a personal prescription.
Enter the amount from your label to see the result.
How it was studied
01 // STUDIED_DOSE_RANGE
Human trial amounts
The dossier discusses 4-12 mg/day of declared astaxanthin, commonly over 6-12 weeks. Safety reports include approximately 12-20 mg/day, which is not an established long-term safe ceiling.
02 // TIMING_&_MATRIX
Lipid matrix matters
Trials and pharmacokinetic work support fat-dependent absorption; weekly bolus schedules are not established.
03 // EVALUATION_WINDOW
Usually 6-12 weeks
Most skin and metabolic studies evaluated repeated intake over weeks rather than immediate effects.
04 // SAFETY_&_QUALITY_GATE
Check context and label
The dossier quotes an EFSA ADI of 0.2 mg/kg/day; an ADI is not a fixed supplemental UL and the regulatory attribution was not independently checked. No fixed EFSA/NIH UL is entered. Pregnancy/lactation and pediatric supplementation have insufficient safety data. Review anticoagulants, blood-pressure and diabetes treatment. Check crustacean allergens in krill/shrimp blends. Reversible orange-red stool or skin and gastrointestinal symptoms can occur; unexplained bleeding or new visual/hormonal symptoms need assessment.
UPPER LIMIT // The dossier quotes an EFSA ADI of 0.2 mg/kg/day; an ADI is not a fixed supplemental UL and the regulatory attribution was not independently checked. No fixed EFSA/NIH UL is entered.
Summary
Small trials suggest skin or eye-comfort effects and modest antioxidant biomarker changes. Combination products, manufacturer links and null trials limit confidence; no human lifespan benefit or sunscreen replacement is established.
Mechanism
A membrane-associated carotenoid with antioxidant activity. Laboratory antioxidant potency and changes in oxidative-stress markers do not quantify clinical protection.
Typical studied dose
The dossier discusses 4-12 mg/day of declared astaxanthin, commonly over 6-12 weeks. Safety reports include approximately 12-20 mg/day, which is not an established long-term safe ceiling.
Upper limit
The dossier quotes an EFSA ADI of 0.2 mg/kg/day; an ADI is not a fixed supplemental UL and the regulatory attribution was not independently checked. No fixed EFSA/NIH UL is entered.
Popular stacks with Astaxanthin
Not enough stack data yet. A combination with Astaxanthin appears here once 5 people rate the same set.
Forms and label traps
| Form on label | Active content | Studied range / day | Absorption & GI tolerance | Verdict |
|---|---|---|---|---|
| Algal oleoresin, explicitly standardized to 10% astaxanthin Best for: Label comparison against the preparation actually studied. |
10% elemental / active | 4–12 mg | Absorption depends on lipid formulation and food fat. Usually well tolerated; stool discoloration and mild GI symptoms occur. |
Studied standard [REFERENCE // LABEL_BASIS] Only apply 10% when the label explicitly specifies that concentration. If the label already lists astaxanthin mg, use active/elemental mode. |
| Synthetic astaxanthin, declared astaxanthin mass Best for: Label comparison against the preparation actually studied. |
Extract weight · ~100% marker | no comparable trial range | Human comparative evidence is limited. Tolerance depends on the amount and individual sensitivity. |
Caution [CAUTION // CHECK_FORM] Different stereoisomer profile; no reliable equivalent human trial range is established here. Zero bounds mean no validated comparison, not a zero dose target. |
| Enhanced formulation, declared astaxanthin mass Best for: Label comparison against the preparation actually studied. |
100% elemental / active | 4–12 mg | Lipid/micellar formulations can increase measured exposure. Tolerance depends on the amount and individual sensitivity. |
Caution [CAUTION // CHECK_FORM] Enter the declared astaxanthin content, not total carrier weight. Increased exposure does not demonstrate superior clinical outcomes. |
Common label traps
- TRAP_01 // Internal sunscreen replaces SPF
Small skin studies do not establish sunscreen-equivalent protection. Continue established sun protection. - TRAP_02 // Thousands of times stronger than vitamin C means better health
An in-vitro antioxidant comparison is not a human clinical effect size. - TRAP_03 // Mouse lifespan results prove human anti-aging
Mouse findings vary and no human survival trial is supplied. - TRAP_04 // Astaxanthin boosts testosterone
The cited hormonal study combined saw palmetto with astaxanthin and cannot isolate its effect.
Other outcomes studied
Outside the five leaderboard goals. Same evidence levels as above.
- SKIN Limited · benefit
Small 6-12-week studies suggest hydration/elasticity or water-loss improvements, often in middle-aged women. Collagen combinations and manufacturer affiliation limit attribution.
PMID 32202443 PMID 39804624 PMID 22428137 PMID 24955642 - EYE STRAIN Limited · benefit
Small child/adult trials suggest eye-fatigue or choroidal-flow changes, without large independent replication.
PMID 40014233 PMID 22072378 - OXIDATIVE BIOMARKERS Moderate · benefit
A meta-analysis reported mild reductions in oxidative/inflammatory biomarkers, not established disease prevention.
PMID 35091276 - LIPIDS Limited · benefit
Small overweight/prediabetes trials reported selected triglyceride, HDL or modified-LDL changes; effects are inconsistent and not generalizable to normal lipids.
PMID 21964877 PMID 34959932 - GLUCOSE Limited · benefit
Small PCOS and type 2 diabetes trials suggest improved insulin-resistance or glucose markers over 8-12 weeks.
PMID 37874168 PMID 29384321 PMID 34959932 - VASCULAR MARKERS Limited · benefit
Positive signals in diabetes/PCOS contrast with null arterial-stiffness/oxidative-stress findings in kidney-transplant recipients.
PMID 29384321 PMID 37874168 PMID 26675778 - EXERCISE RECOVERY Limited · benefit
A pooled recovery-biomarker signal contrasts with null muscle-damage/inflammation findings in trained men. This does not guarantee improved performance.
PMID 42197030 PMID 36727984 - COGNITION Limited · benefit
Small cognition studies used astaxanthin plus sesamin or other ingredients, preventing isolated attribution.
PMID 29614679 PMID 38892705 - MALE FERTILITY Limited · benefit
A small historical adjunctive-treatment trial reported selected semen changes; modern independent replication is missing.
PMID 16110353 - HORMONAL CLAIMS Limited · no benefit
A saw-palmetto/astaxanthin product cannot establish isolated effects on DHT or testosterone.
PMID 25183955
Reader questions
Is 12 mg better than 4 or 8 mg?
Trials use different populations, formulations and endpoints. The supplied evidence does not establish one universally optimal amount.
Can it replace sunscreen?
No. A change in skin biomarkers or UV response does not establish SPF-equivalent protection.
Can it affect libido or hormones?
The dossier lacks an isolated human astaxanthin trial proving this effect. Combination studies and individual reports cannot establish causation.
Are expensive formulations worth more?
Pharmacokinetic studies show altered exposure. Their price premium is not justified by proven superiority on clinical endpoints; food fat also affects absorption.
Stack interactions
- Caution Diabetes medicines [CAUTION // REVIEW_COMBINATION]
Possible additive glucose lowering from small clinical-population trials; actual combination hypoglycemia risk is not established.
PMID 29384321 PMID 37874168 - Caution Blood-pressure medicines [CAUTION // REVIEW_COMBINATION]
Potential additive lowering; results vary by population and require clinical review.
PMID 29384321 PMID 37874168 - Caution Anticoagulants and antiplatelet medicines [CAUTION // REVIEW_COMBINATION]
The platelet/coagulation evidence cited is from rats, so this remains precautionary rather than a proven human interaction.
PMID 27951728 - Caution Food fat and other carotenoids [CAUTION // REVIEW_COMBINATION]
Fat can improve absorption. Competition with other carotenoids is theoretical; no clinically important antagonism is established.
PMID 12885395
Red flags: interactions and who should avoid it
Interactions
Diabetes medicines: Possible additive glucose lowering from small clinical-population trials; actual combination hypoglycemia risk is not established. Blood-pressure medicines: Potential additive lowering; results vary by population and require clinical review. Anticoagulants and antiplatelet medicines: The platelet/coagulation evidence cited is from rats, so this remains precautionary rather than a proven human interaction. Food fat and other carotenoids: Fat can improve absorption. Competition with other carotenoids is theoretical; no clinically important antagonism is established.
Avoid or ask a doctor first if
Pregnancy/lactation and pediatric supplementation have insufficient safety data. Review anticoagulants, blood-pressure and diabetes treatment. Check crustacean allergens in krill/shrimp blends. Reversible orange-red stool or skin and gastrointestinal symptoms can occur; unexplained bleeding or new visual/hormonal symptoms need assessment.
Sources (PubMed, 26)
- Safety of an astaxanthin-rich Haematococcus pluvialis algal extract: a randomized clinical trial.
PMID 12804020 · 2003 · Clinical Trial; Journal Article; Randomized Controlled Trial; Research Support; Non-U.S. Gov'tDossier citation for preparation, pharmacokinetics or safety context; does not independently establish every efficacy or interaction claim on this card.
- Oral bioavailability of the antioxidant astaxanthin in humans is enhanced by incorporation of lipid based formulations.
PMID 12885395 · 2003 · Comparative Study; Journal ArticleDossier citation for preparation, pharmacokinetics or safety context; does not independently establish every efficacy or interaction claim on this card.
- Combined conventional/antioxidant \"Astaxanthin\" treatment for male infertility: a double blind, randomized trial.
PMID 16110353 · 2005 · Clinical Trial; Journal Article; Randomized Controlled Trial; Research Support; Non-U.S. Gov'tA small historical adjunctive-treatment trial reported selected semen changes; modern independent replication is missing.
- Rapid baseline separation of enantiomers and a mesoform of all-trans-astaxanthin, 13-cis-astaxanthin, adonirubin, and adonixanthin in standards and commercial supplements.
PMID 18486137 · 2008 · Journal Article; Research Support; N.I.H.; ExtramuralDossier citation for preparation, pharmacokinetics or safety context; does not independently establish every efficacy or interaction claim on this card.
- Positive effects of astaxanthin on lipid profiles and oxidative stress in overweight subjects.
PMID 21964877 · 2011 · Journal Article; Randomized Controlled Trial; Research Support; Non-U.S. Gov'tSmall overweight/prediabetes trials reported selected triglyceride, HDL or modified-LDL changes; effects are inconsistent and not generalizable to normal lipids.
- Astaxanthin increases choroidal blood flow velocity.
PMID 22072378 · 2012 · Journal Article; Randomized Controlled Trial; Research Support; Non-U.S. Gov'tSmall child/adult trials suggest eye-fatigue or choroidal-flow changes, without large independent replication.
- Cosmetic benefits of astaxanthin on humans subjects.
PMID 22428137 · 2012 · Journal Article; Randomized Controlled TrialSmall 6-12-week studies suggest hydration/elasticity or water-loss improvements, often in middle-aged women. Collagen combinations and manufacturer affiliation limit attribution.
- Supplementating with dietary astaxanthin combined with collagen hydrolysate improves facial elasticity and decreases matrix metalloproteinase-1 and -12 expression: a comparative study with placebo.
PMID 24955642 · 2014 · Comparative Study; Journal Article; Randomized Controlled Trial; Research Support; Non-U.S. Gov'tSmall 6-12-week studies suggest hydration/elasticity or water-loss improvements, often in middle-aged women. Collagen combinations and manufacturer affiliation limit attribution.
- Evaluation of Resettin® on serum hormone levels in sedentary males.
PMID 25183955 · 2014 · Journal ArticleA saw-palmetto/astaxanthin product cannot establish isolated effects on DHT or testosterone.
- Astaxanthin has no effect on arterial stiffness, oxidative stress, or inflammation in renal transplant recipients: a randomized controlled trial (the XANTHIN trial).
PMID 26675778 · 2016 · Journal Article; Randomized Controlled Trial; Research Support; Non-U.S. Gov'tPositive signals in diabetes/PCOS contrast with null arterial-stiffness/oxidative-stress findings in kidney-transplant recipients.
- Effects of astaxanthin on blood coagulation, fibrinolysis and platelet aggregation in hyperlipidemic rats.
PMID 27951728 · 2017 · Journal ArticleDossier citation for preparation, pharmacokinetics or safety context; does not independently establish every efficacy or interaction claim on this card.
- Astaxanthin improves glucose metabolism and reduces blood pressure in patients with type 2 diabetes mellitus.
PMID 29384321 · 2018 · Journal Article; Randomized Controlled TrialSmall PCOS and type 2 diabetes trials suggest improved insulin-resistance or glucose markers over 8-12 weeks.
- Effects of Composite Supplement Containing Astaxanthin and Sesamin on Cognitive Functions in People with Mild Cognitive Impairment: A Randomized, Double-Blind, Placebo-Controlled Trial.
PMID 29614679 · 2018 · Journal Article; Randomized Controlled TrialSmall cognition studies used astaxanthin plus sesamin or other ingredients, preventing isolated attribution.
- A Study on the Bioavailability of a Proprietary, Sustained-release Formulation of Astaxanthin.
PMID 30962794 · 2018 · Journal ArticleDossier citation for preparation, pharmacokinetics or safety context; does not independently establish every efficacy or interaction claim on this card.
- Effects of Astaxanthin Supplementation on Skin Health: A Systematic Review of Clinical Studies.
PMID 32202443 · 2021 · Journal Article; Systematic ReviewSmall 6-12-week studies suggest hydration/elasticity or water-loss improvements, often in middle-aged women. Collagen combinations and manufacturer affiliation limit attribution.
- The Beneficial Effects of Astaxanthin on Glucose Metabolism and Modified Low-Density Lipoprotein in Healthy Volunteers and Subjects with Prediabetes.
PMID 34959932 · 2021 · Journal Article; Randomized Controlled TrialSmall overweight/prediabetes trials reported selected triglyceride, HDL or modified-LDL changes; effects are inconsistent and not generalizable to normal lipids.
- Astaxanthin supplementation mildly reduced oxidative stress and inflammation biomarkers: a systematic review and meta-analysis of randomized controlled trials.
PMID 35091276 · 2022 · Journal Article; Meta-Analysis; Research Support; Non-U.S. Gov't; Systematic ReviewA meta-analysis reported mild reductions in oxidative/inflammatory biomarkers, not established disease prevention.
- Astaxanthin Supplementation Does Not Affect Markers of Muscle Damage or Inflammation After an Exercise-Induced Muscle Damage Protocol in Resistance-Trained Males.
PMID 36727984 · 2023 · Journal Article; Randomized Controlled TrialA pooled recovery-biomarker signal contrasts with null muscle-damage/inflammation findings in trained men. This does not guarantee improved performance.
- Astaxanthin supplementation impact on insulin resistance, lipid profile, blood pressure, and oxidative stress in polycystic ovary syndrome patients: A triple-blind randomized clinical trial.
PMID 37874168 · 2024 · Randomized Controlled Trial; Journal ArticleSmall PCOS and type 2 diabetes trials suggest improved insulin-resistance or glucose markers over 8-12 weeks.
- Safety of a change in specifications of the novel food oleoresin from Haematococcus pluvialis containing astaxanthin pursuant to Regulation (EU) 2015/2283.
PMID 38027444 · 2023 · Journal ArticleDossier citation for preparation, pharmacokinetics or safety context; does not independently establish every efficacy or interaction claim on this card.
- Comparative Pharmacokinetic Study of Standard Astaxanthin and its Micellar Formulation in Healthy Male Volunteers.
PMID 38748358 · 2024 · Journal Article; Comparative Study; Randomized Controlled TrialDossier citation for preparation, pharmacokinetics or safety context; does not independently establish every efficacy or interaction claim on this card.
- An Examination into the Effects of a Nutraceutical Supplement on Cognition, Stress, Eye Health, and Skin Satisfaction in Adults with Self-Reported Cognitive Complaints: A Randomized, Double-Blind, Placebo-Controlled Trial.
PMID 38892705 · 2024 · Journal Article; Randomized Controlled TrialSmall cognition studies used astaxanthin plus sesamin or other ingredients, preventing isolated attribution.
- Oral Supplements and Photoprotection: A Systematic Review.
PMID 39804624 · 2025 · Journal Article; Systematic ReviewSmall 6-12-week studies suggest hydration/elasticity or water-loss improvements, often in middle-aged women. Collagen combinations and manufacturer affiliation limit attribution.
- Astaxanthin (AstaReal®) Improved Acute and Chronic Digital Eye Strain in Children: A Randomized Double-Blind Placebo-Controlled Trial.
PMID 40014233 · 2025 · Journal Article; Randomized Controlled Trial; Research Support; Non-U.S. Gov'tSmall child/adult trials suggest eye-fatigue or choroidal-flow changes, without large independent replication.
- Absorption characteristics and in vivo behavior of astaxanthin isomers: insights from the administration of highly purified (all-E)-, (9Z)-, and (13Z)-astaxanthin in male mice.
PMID 41220623 · 2025 · Journal ArticleDossier citation for preparation, pharmacokinetics or safety context; does not independently establish every efficacy or interaction claim on this card.
- The Effects of Astaxanthin Supplementation on Exercise Recovery Biomarkers and Exercise Performance: A Systematic Review and Meta-Analysis.
PMID 42197030 · 2026 · Journal Article; Systematic Review; Meta-AnalysisA pooled recovery-biomarker signal contrasts with null muscle-damage/inflammation findings in trained men. This does not guarantee improved performance.
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