Buy Astaxanthin NZ
Menu

The research

The astaxanthin
research library

The human trials, organised by body system.
Every study linked straight to PubMed.
Read the evidence, and its limits, yourself.
Reviewed by  Dr Ron Goedeke     ·    Every study on PubMed    ·    Last checked June 2026
Every study behind this site, grouped by body system and linked straight to PubMed, so nothing has to be taken on trust. The evidence isn’t equally strong everywhere and the tags say so: heart and skin rest on meta-analyses, eyes are modest, exercise is mixed, joints and brain are thin. It’s a curated selection of the strongest human research, not the whole literature; it flags combination products and specific patient groups, and leaves out the animal-only and marketing padding common to astaxanthin reading lists (joints excepted, and clearly marked).

Jump to

01

How it works

02

Skin

03

Eyes

04

Heart

05

Joints

06

Brain

07

Exercise

08

Reproductive health

09

Immune

10

Absorption

11

Safety

12

Animal (dogs)

01 ·

 3 studies

How astaxanthin works

The mechanism and overview reviews that underpin everything else.

Fakhri (2018)

REVIEW
Reviews astaxanthin’s antioxidant and anti-inflammatory mechanisms and its documented biological activities across body systems.
PubMed 30121358

Donoso (2021)

Review
An evidence-based review focused specifically on astaxanthin’s human clinical trials; reports antioxidant capacity many times that of vitamin E.
PubMed 33549728

Ambati (2014)

Review
Reviews astaxanthin’s natural sources, extraction and stability; Haematococcus algae holds up to 3.8% astaxanthin by dry weight.
PubMed 24402174

02 ·

 5 studies

Skin

Among the strongest and most consistent human evidence, now including meta-analysis.

Zhou (2021)

Meta-analysis
Pooled nine randomised skin trials: oral astaxanthin significantly improved skin moisture and elasticity, but did not significantly reduce wrinkle depth.
PubMed 34578794

Tominaga (2012)

RCT
At 6 mg a day, improved skin wrinkles, elasticity, age spots and moisture in both women and men.
PubMed 22428137

Ito (2018)

RCT
At 4 mg a day, improved the skin’s resistance to UV (raised the minimal erythema dose) and reduced UV-induced moisture loss in healthy adults.
PubMed 29941810

Davinelli (2018)

Review
Comprehensive review of astaxanthin’s photoprotective, antioxidant and anti-inflammatory effects in skin.
PubMed 29690549

Ng (2020)

Systematic review
Reviewed eleven skin trials: improvements in texture, wrinkles and moisture, with no serious adverse events reported.
PubMed 32202443

03 ·

 5 studies

Eyes

Real but modest benefits, mostly around eye strain, focusing and ocular blood flow.

Saito (2012)

Clinical trial
At 12 mg a day, improved choroidal (retinal) blood flow.
PubMed 22072378

Hashimoto (2013)

Clinical study
At 6 mg a day, raised antioxidant activity and lowered oxidative markers in the eye’s aqueous humour.
PubMed 23874063

Kizawa (2021)

RCT
A combination of astaxanthin, anthocyanin and lutein improved focusing (accommodation) in adults with screen-related eye fatigue. A combination product, so astaxanthin’s individual role isn’t isolated.
PubMed 34376917

Hecht (2025)

RCT
At 4 mg a day, reduced digital eye strain and visual fatigue in school-aged children.
PubMed 40014233

Martinez-Perez (2025)

Systematic review
Carotenoids including astaxanthin gave modest benefits for visual fatigue, but no consistent effect on myopia progression.
PubMed 41515122

04 ·

 9 studies

Heart and cardiovascular

The best-evidenced area. Astaxanthin reliably raises HDL, lowers triglycerides, and reduces inflammation and LDL oxidation. Its effect on LDL levels is genuinely mixed: several meta-analyses find none, but longer trials in higher-risk groups such as prediabetes and coronary disease show real LDL and total-cholesterol reductions. Both sides are shown below.

Yoshida (2010)

RCT
Raised HDL cholesterol and adiponectin and lowered triglycerides in people with mildly high triglycerides.
PubMed 19892350

Choi (2011)

RCT
Lowered LDL, ApoB and oxidative-stress markers in overweight adults.
PubMed 21964877

Mashhadi (2018)

RCT
Lowered triglycerides and systolic blood pressure in people with type 2 diabetes.
PubMed 29384321

Ciaraldi (2023)

RCT
In adults with prediabetes and dyslipidaemia, 12 mg a day for 24 weeks significantly lowered LDL and total cholesterol and reduced several cardiovascular-risk markers (fibrinogen, L-selectin, fetuin-A). NIH-funded, and one of the longer trials.
PubMed 36999233

Heidari (2023)

RCT
In people with coronary artery disease, 12 mg a day for 8 weeks significantly lowered total cholesterol and LDL, with no change in triglycerides or HDL.
PubMed 37051124

Xia (2020)

Meta-analysis
Pooled 14 randomised trials: astaxanthin reliably raised HDL, and lowered CRP at higher doses, but did not change LDL or blood pressure overall.
PubMed 32755613

Leung (2022)

Meta-analysis
In adults at risk of metabolic syndrome, pooled trials found a significant LDL-lowering effect, plus marginal reductions in total cholesterol and systolic blood pressure.
PubMed 35631193

Fornari Laurindo (2025)

Meta-analysis
Higher-dose analysis: raised HDL and lowered triglycerides, with no significant change in LDL or total cholesterol.
PubMed 40872489

Mohammadi (2025)

RCT
In 80 people with chronic heart failure, 20 mg a day for 8 weeks improved antioxidant capacity, lowered oxidative-stress markers and serum uric acid, and improved dyspnea and fatigue versus placebo.
PubMed 41162864

05 ·

 7 studies

Joints

Still the thinnest human evidence of any area here, but no longer empty: two human trials now exist, one in rheumatoid arthritis using astaxanthin alone and one in osteoarthritis using a combination product. Both are recent and modest. The mechanism is well supported in animal and laboratory models, several of which are included below and clearly marked as preclinical.

Grigorian (2025)

RCT
In 60 people with rheumatoid arthritis, 20 mg a day of astaxanthin alone for 8 weeks significantly improved disease activity (DAS-28), physical function (HAQ) and ESR versus placebo. The effect on pain was only marginal and IL-6 didn’t change. This is the only trial to test astaxanthin on its own for a joint condition.
PubMed 40569081

Hill (2023)

RCT
A combination of krill oil, astaxanthin and hyaluronic acid reduced joint pain in people with mild knee or hip osteoarthritis. Manufacturer-funded, and unlike the trial above, astaxanthin’s individual contribution can’t be isolated.
PubMed 37686801

Sun (2019)

Animal study
In a mouse osteoarthritis model and in cartilage cells, astaxanthin protected cartilage and reduced inflammation and breakdown by activating the Nrf2 antioxidant pathway. Preclinical only.
PubMed 31772142

Qin (2024)

Animal study

In a mouse osteoarthritis model and in cartilage cells, astaxanthin reduced inflammation and protected cartilage by upregulating SIRT1. Preclinical only.
PubMed 38555717

Wang (2022)

Animal study

In rat cartilage cells and a rat osteoarthritis model, astaxanthin slowed cartilage breakdown by inhibiting ferroptosis (iron-driven cell death) and protecting mitochondrial function. Preclinical only.
PubMed 36084724

Huang (2015)

Animal study

In a rabbit osteoarthritis model, astaxanthin reduced cartilage degradation and suppressed the cartilage-degrading enzymes (MMP-1, -3 and -13) that drive joint damage. Preclinical only.
PubMed 25608048

Kumar (2019)

Animal study

In a rat model of rheumatoid-type (adjuvant-induced) arthritis, oral astaxanthin reduced paw swelling, improved arthritis scores and lowered inflammatory and oxidative markers. Preclinical only.
PubMed 32016833

06 ·

 5 studies

Brain and cognition

A compelling mechanism, but early and statistically weak human data.

Katagiri (2012)

RCT
Cognitive scores improved in older adults with age-related forgetfulness, though the trial was too small to reach statistical significance versus placebo.
PubMed 22962526

Ito (2018)

RCT
Astaxanthin combined with sesamin improved processing and psychomotor speed in people with mild cognitive impairment. A small manufacturer-run pilot.
PubMed 29614679

Liu (2024)

Meta-analysis
Pooled eleven trials: the effect on cognition was only marginally significant for accuracy and not significant for reaction time.
PubMed 38243785

Utomo (2024)

Systematic review
Reviewed the cognitive trials: improvements were reported by most participants but weren’t statistically robust.
PubMed 39036318

Grimmig (2017)

Review
Reviews astaxanthin’s neuroprotective mechanisms, including its ability to cross into the brain and calm neuroinflammation.
PubMed 28299644

07 ·

 4 studies

Exercise and physical performance

Promising in theory and in animals, but the human evidence is genuinely mixed: some trials show clear benefits, others show little. Both are shown here.

Tsao (2025)

RCT
In physically active young men, 28 mg a day significantly increased time to exhaustion on a cycling test and reduced markers of muscle damage and oxidative stress. Small (10 participants) and short-term.
PubMed 40615903

Liu (2021)

RCT
In healthy older adults, astaxanthin combined with aerobic training improved muscle endurance and fat oxidation more than training alone.
PubMed 34110707

Wika (2023)

RCT
In overweight adults, 12 mg a day for 4 weeks lowered heart rate and carbohydrate oxidation during exercise, though it did not change fat oxidation.
PubMed 37114194

Brown (2018)

Review
Reviews astaxanthin in exercise: the animal data are promising, but human results for performance and recovery remain mixed and inconsistent.
PubMed 29404334

08 ·

 4 studies

Women's reproductive health

A fast-growing area of recent trials, almost all in specific conditions such as PCOS and infertility, and focused on inflammation, oxidative stress and fertility-treatment outcomes. This is not evidence for boosting fertility in the general population.

Maleki-Hajiagha (2024)

Meta-analysis
Pooled clinical trials: astaxanthin improved oocyte maturation and antioxidant capacity in the follicular fluid of women undergoing fertility treatment; broader pregnancy outcomes were not significantly changed.
PubMed 39127677

Rostami (2023)

RCT
In women with endometriosis undergoing assisted reproduction, 6 mg a day lowered inflammation and oxidative stress and improved egg and embryo measures.
PubMed 37020589

Shafie (2024)

RCT
In women with poor ovarian response, 12 mg a day lowered inflammation and oxidative stress and improved some fertility-treatment outcomes.
PubMed 39482765

Jabarpour (2023)

RCT
In women with PCOS, astaxanthin improved insulin resistance, lipid profile, blood pressure and oxidative stress.
PubMed 37874168

09 ·

 1 studies

Immune function

Human evidence for immune and anti-inflammatory effects.

Park (2010)

RCT
At 2 to 8 mg a day, lowered CRP and a DNA-damage marker and enhanced immune response (antibody levels, natural killer cell activity) in healthy young women.
PubMed 20205737

10 ·

 1 studies

Absorption and dosage

Why astaxanthin is taken with fat, and how long it stays in the body.

Mercke Odeberg (2003)

Pharmacokinetic study
Lipid-based delivery raised astaxanthin’s bioavailability by up to nearly fourfold; its elimination half-life is around 16 hours.
PubMed 12885395

11 ·

 1 studies

Safety

The definitive human safety assessment.

Brendler & Williamson (2019

Safety review
Reviewed 87 human studies of natural astaxanthin, 35 at 12 mg a day or more, and found no safety concerns. Also sets out why natural and synthetic astaxanthin shouldn’t share dose limits.
PubMed 31788888

12 ·

 3 studies

Animal studies (dogs)

The canine evidence behind astaxanthin for pets.

Park (2010)

Animal study
Dogs and cats absorb astaxanthin from the diet, carrying it mainly on HDL and into immune cells, much as humans do.
PubMed 20565958

Chew (2011)

Animal study
Enhanced immune response and lowered inflammation markers in dogs supplemented with astaxanthin.
PubMed 21208664

Murai (2019)

Animal study
Improved antioxidant status and lipid metabolism in both healthy and obese dogs.
PubMed 30859086
Dr Ron

Medically reviewed

Dr Ron Goedeke

Functional medicine physician based in Auckland, with 25 years of clinical experience in nutritional and anti-aging medicine. Founding member of the New Zealand College of Appearance Medicine. Member of the American Academy of Anti-Aging Medicine since 1999.
Last reviewed: JUNE 2026

 About our reviewers

Buy Astaxanthin NZ