Evidence-based·Last reviewed May 31, 2026·How we grade evidence

Neoxanthin

PhytochemicalXanthophyll

A xanthophyll carotenoid pigment abundant in spinach and other green leafy vegetables. Best characterized for its role in plant photosynthesis. Human supplementation evidence is essentially absent — bioavailability from food is very low and there are no clinical trials of isolated neoxanthin.

Quick decision guide

May help most

Eating spinach and other green leafy vegetables as part of a varied diet — the natural and only evidence-aligned way to consume neoxanthin.

Common dosing range

No established supplement dose. Dietary intake from a generous spinach serving is roughly 1-15 mg.

When to expect effects

Not established — no human clinical-endpoint trials exist.

Watch out for

Concentrated neoxanthin supplements are essentially uncharacterized in humans. Skip the capsule; eat the spinach.

Evidence snapshot

Anti-cancer effect (in vitro cell lines)Low

Human bioavailability from foodLow

Antioxidant or photoprotective claims (in humans)Low

Any clinical outcome in humansLow

What is it

Neoxanthin (C40H56O4) is an allenic xanthophyll carotenoid concentrated in the light-harvesting complex of green leafy vegetables (spinach, kale, parsley) where it participates in photosynthesis and photoprotection. Among carotenoids it is structurally unusual in carrying an allene bond (C=C=C) and is the biosynthetic precursor of plant abscisic acid.

Is it worth it for you?

Use this as a quick fit check, not a diagnosis.

Worth considering if…

You're researching carotenoid chemistry or plant biochemistry

You want to understand why a marketed 'neoxanthin' supplement is unlikely to do what its label promises

Probably skip if…

You're considering a neoxanthin supplement for cancer prevention or treatment — only cell-line evidence exists

You're hoping a capsule will deliver photoprotection or skin-aging benefits — no human trial exists

You're paying premium prices for an isolated xanthophyll — eat spinach instead

You want a 'mixed carotenoid' product banking on neoxanthin's contribution — lutein and zeaxanthin have the real evidence

Evidence at a glance

Goal	Effect	Best fit	Time
Anti-cancer activity (cell-line only) Mixed Evidence	60-100% reduction in cancer-cell viability at 20 micromolar (in vitro only)	Nobody — no clinical evidence in humans	Not applicable (in vitro)
Antioxidant activity (mechanistic) Mixed Evidence	No measurable human clinical outcome data	Nobody specifically — get carotenoids from green vegetables	Not established

Anti-cancer activity (cell-line only)

Mixed Evidence

Effect: 60-100% reduction in cancer-cell viability at 20 micromolar (in vitro only)
Best fit: Nobody — no clinical evidence in humans
Time: Not applicable (in vitro)

Antioxidant activity (mechanistic)

Mixed Evidence

Effect: No measurable human clinical outcome data
Best fit: Nobody specifically — get carotenoids from green vegetables
Time: Not established

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Anti-cancer activity (cell-line only)

Mechanism only

Mixed Evidence

The Kotake-Nara 2001 study found that neoxanthin and fucoxanthin reduced viability of cultured human prostate cancer cells (LNCaP, DU145, PC-3) by 60-100% at 20 micromolar concentrations, with evidence of apoptosis induction. This is cell-culture data only. No animal model, no human trial, and no evidence that the 20 micromolar concentration is achievable in human prostate tissue via oral supplementation (it is not — plasma levels are typically undetectable).

Effect size

60-100% reduction in cancer-cell viability at 20 micromolar (in vitro only)

Time to effect

Not applicable (in vitro)

Best fit

Nobody — no clinical evidence in humans

Less likely

Patients hoping a neoxanthin supplement will treat or prevent prostate cancer

Bottom line: Cell-line data only. Don't take neoxanthin supplements for cancer prevention or treatment — there is no human evidence.

SourceKotake-Nara et al., 2001 — Journal of Nutrition

Antioxidant activity (mechanistic)

Mechanism only

Mixed Evidence

Like other carotenoids, neoxanthin has in-vitro antioxidant activity (singlet oxygen quenching, free-radical scavenging). Translation to humans is limited by very poor bioavailability — plasma neoxanthin is rarely measurable even after large spinach servings. No clinical-endpoint trial of neoxanthin for any condition exists.

Effect size

No measurable human clinical outcome data

Time to effect

Not established

Best fit

Nobody specifically — get carotenoids from green vegetables

Less likely

Adults expecting measurable benefit from an isolated neoxanthin supplement

Bottom line: Mechanistic story without human evidence. Eat the spinach.

SourceDembitsky et al., 2008 — Mini-Reviews in Medicinal Chemistry Linus Pauling Institute Micronutrient Information Center — LPI — Carotenoids

How to take it

1. Typical dose

• No established supplement dose • Dietary intake from food: 1-15 mg per generous serving of spinach or other green leafy vegetables • Most supplement products mix neoxanthin with lutein, zeaxanthin, and other xanthophylls without disclosing individual doses

2. Higher studied dose

Not characterized in humans. Cell-line studies used 20 micromolar concentrations that are not realistically achievable via oral supplementation.

3. Timing

If consuming via food, take with a meal containing some fat — carotenoids are fat-soluble and require dietary fat for absorption.

4. With food

With food (fat-soluble; requires dietary fat for absorption).

5. Split dosing

Not applicable — no established supplementation regimen.

6. How long to try

Not applicable — no clinical evidence to support any specific supplementation duration.

What to track

Servings of green leafy vegetables per week (food intake is the meaningful exposure)

Co-occurring lutein/zeaxanthin intake — these are the better-evidenced carotenoids from the same food sources

Bottom line: Skip the capsule. Eat spinach, kale, broccoli, and other green leafy vegetables for the carotenoid-rich diet evidence supports.

3 commercial forms

Compare the main delivery options and what they’re best suited for.

Whole-food source (spinach, kale, parsley, broccoli)

Food-first

The natural and only evidence-aligned way to consume neoxanthin. A generous spinach serving delivers 1-15 mg alongside other carotenoids, vitamins, and dietary fiber. Even from food, neoxanthin bioavailability is very low — but the overall vegetable intake is what the dietary-pattern evidence supports.

Very low bioavailability even from food (~undetectable in plasma in most subjects).

Isolated neoxanthin supplement

Uncharacterized

Rarely sold as a standalone product. When included, usually as a minor component of 'mixed carotenoid' blends. No clinical-endpoint trial of any isolated neoxanthin supplement exists.

Unknown bioavailability from supplement matrix; clinical effects undocumented.

Microalgae extracts

Source material

Some green-microalgae products (e.g. Dunaliella) contain neoxanthin alongside other carotenoids. Marketed primarily for the carotenoid mix; neoxanthin's individual contribution has not been clinically isolated.

Bioavailability depends on product matrix; not clinically characterized.

Safety

Know the common side effects, key cautions, and who should avoid it.

Common side effects

no characterized side effects from food intake or isolated supplements

Serious risks

Long-term safety of concentrated neoxanthin supplementation in humans is not characterized. The allene chemistry is labile and degradation products during storage are not well documented in supplement contexts.
SourceLinus Pauling Institute Micronutrient Information Center — LPI — Carotenoids

Who should avoid it

Pregnant or breastfeeding people — no safety data for isolated neoxanthin supplements.
SourceLinus Pauling Institute Micronutrient Information Center — LPI — Carotenoids
Anyone considering it instead of evidence-based therapy for a serious condition — talk to your treating clinician.
SourceLinus Pauling Institute Micronutrient Information Center — LPI — Carotenoids

Pregnancy & breastfeeding

Neoxanthin from food (leafy vegetables) is safe and beneficial in pregnancy as part of a varied diet. Isolated neoxanthin supplements lack pregnancy safety data — avoid.

SourceLinus Pauling Institute Micronutrient Information Center — LPI — Carotenoids

Bottom line: Food is safe. Isolated supplements are uncharacterized in humans and not recommended.

Interactions

fat-soluble vitamins (A, D, E, K)Minor

Like other carotenoids, neoxanthin requires dietary fat and shares absorption pathways with other fat-soluble nutrients. Theoretical competition at high supplemental doses; rarely a practical concern at dietary intakes.

SourceLinus Pauling Institute Micronutrient Information Center — LPI — Carotenoids

Food sources

Food	Amount	%DV
Spinach, raw	1 cup (~5-15 mg)	—
Kale, raw	1 cup (~2-8 mg)	—
Parsley, fresh	½ cup (~3-6 mg)	—
Lettuce (romaine, leaf)	1 cup (~1-3 mg)	—
Broccoli, cooked	½ cup (~1-3 mg)	—
Green peas, cooked	½ cup (~0.5-2 mg)	—
Spirulina / chlorella algae	1 Tbsp (trace)	—

Spinach, raw

Amount: 1 cup (~5-15 mg)
%DV: —

Kale, raw

Amount: 1 cup (~2-8 mg)
%DV: —

Parsley, fresh

Amount: ½ cup (~3-6 mg)
%DV: —

Lettuce (romaine, leaf)

Amount: 1 cup (~1-3 mg)
%DV: —

Broccoli, cooked

Amount: ½ cup (~1-3 mg)
%DV: —

Green peas, cooked

Amount: ½ cup (~0.5-2 mg)
%DV: —

Spirulina / chlorella algae

Amount: 1 Tbsp (trace)
%DV: —

Choosing a product

What to look for on the label — and what to be skeptical of.

Look for…

If you want lutein and zeaxanthin (the better-evidenced xanthophylls), look for products that label those individually — neoxanthin alone has no clinical evidence

Third-party tested (USP, NSF) — standalone neoxanthin supplements are rarely independently verified

Stored in dark, cool conditions — allene-containing carotenoids degrade with light and heat

Be skeptical of…

'Powerful anti-cancer compound' marketing based on cell-culture data

'Anti-aging' or 'photoprotection' claims with no human trial support

'Antioxidant superfood' supplements that hide individual carotenoid doses inside a blend

Any supplement claiming neoxanthin will deliver clinical benefit not demonstrated in any human study

References by claim

Anti-cancer activity (cell-line only)

Kotake-Nara et al., 2001 — Journal of Nutrition (2001) link

Antioxidant activity (mechanistic)

Linus Pauling Institute Micronutrient Information Center — LPI — Carotenoids (2016) link

Dembitsky et al., 2008 — Mini-Reviews in Medicinal Chemistry (2008) link

Other references

Asai et al., 2008 — Journal of Agricultural and Food Chemistry (2008) link

Strand et al., 2000 — European Journal of Clinical Nutrition (2000) link

Neoxanthin on Wikidata — Wikidata (2024) link

Track Neoxanthin with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

Coming to App Store

Evidence-based·Last reviewed May 31, 2026·Evidence current as of May 31, 2026·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.