Zeaxanthin: Benefits, Side Effects, Best Time to Take It & More

Zeaxanthin

(Xanthophyll Carotenoid)

Amount of Evidence: Low
Potential Benefits: Reasonable
Safety: High

What is zeaxanthin?

Zeaxanthin is a carotenoid found primarily in leafy green vegetables. It is similar as far as its structure and effects to lutein. As a dietary supplement, this carotenoid is mainly used for improving vision and eye health. Unfortunately, it does not seem to be effective for anything but improving eye health. In this article, we will look at the main benefits of zeaxanthin, its potential side effects, and how to use it the right way.

Potential benefits

It is important to note that all of the potential benefits mentioned below are dose-dependent. In general, the higher the dose you take, the more pronounced the effects will be. However, they do reach a plateau at a certain point. We will discuss the best dosing protocol later in this article.

Major benefits

Improved eye health – Zeaxanthin can notably increase ocular blood flow and a few other markers connected with eye health. The carotenoid also protects retinal cells from oxidation.

Minor benefits

Protection from ARMD – ARMD (Age-related macular degeneration) affects around 5% of people over 65 years old. The carotenoid can increase total macular pigment levels and reduce the risk of ARMD.

Unproven benefits

The effect of zeaxanthin on these parameters has either not been adequately researched, or the science shows little to no efficacy in these areas.

Cognition – This effect was disproven by a study where zeaxanthin has shown no impact on cognition after one year.
Blood flow – No significant change has ever been observed.
CRP (C-reactive protein) – Zeaxanthin doesn’t seem to affect CRP.
Blood pressure – There is no strong evidence that the supplement affects blood pressure in healthy individuals.
DNA protection – While one study found a huge reduction in DNA damage, other studies found no effect. We need more research to confirm that this carotenoid protects DNA cells.
Inflammation – The supplement does not significantly affect inflammation, at least not directly.
Triglycerides – No significant influence has ever been found.
Cholesterol – The supplement has no direct effect on HDL or LDL cholesterol levels.
VO2 max – The supplement does not appear to directly improve your VO2 max.
Risk of stroke – Relative to placebo, zeaxanthin supplements have never been shown to reduce the risk of stroke.
Serum T3 and T4 – There is no significant interaction between the supplement and serum T3 and T4.
Well-being – The supplements do not reduce rates of depression or increase subjective well-being.
Weight – Supplementation does not cause weight loss or weight gain.
Strength – The carotenoid does not help you gain strength or muscle mass faster.
Asthma – The supplement has not been shown to help with asthma to a significant degree.
Power output – This carotenoid does not directly influence power output during cardio or resistance training. It does not impact endurance either.
Kidney function – Biomarkers of kidney function are not significantly altered by taking zeaxanthin compared to placebo.
Sleep quality – The supplement does not appear to improve sleep quality. It also doesn’t directly affect sleep duration.
Stress and anxiety – Oral supplements have no direct effect on cortisol levels.
Metabolic rate – The supplement does not speed up or slow down your metabolism.

Possible side effects

These side effects are dose-dependent and the risk for them increases (most often linearly but sometimes exponentially) as the dose is increased. Some of the side effects only apply to very high doses.

Diarrhea – This side effect is not dangerous (assuming diarrhea doesn’t cause severe dehydration) and usually only occurs if you take very high doses at once.
Nausea – Just like diarrhea, this side effect is not dangerous but can be unpleasant.
Toxicity – The toxic dose is not yet known and may not even exist. As much as 50 mg daily has been proven to be safe. With that said, taking very high amounts for a prolonged period of time could lead to side effects that have not yet been well-documented.

Who should not take zeaxanthin?

You should probably avoid taking the supplement if you:

are on a tight supplement budget (since there are more cost-effective supplements out there)
experience a severe adverse reaction (such as nausea or diarrhea) after taking the supplement

Who will benefit the most?

You should consider taking the supplement if you:

prioritize eye health or suffer from ARMD
have a high budget for supplements (since zeaxanthin will probably do slightly more good than harm)

How much zeaxanthin should you take?

The ideal dose of zeaxanthin appears to be around 2-3 mg daily. This should provide most of the benefits without meaningful side effects

While you could safely take more than that, it is by no means necessary. Higher amounts also increase the risk of unwanted side effects.

Food sources of zeaxanthin

Leafy green vegetables are by far the richest food group in zeaxanthin. As little as 50 grams of cooked spinach and many other leafy greens should provide more than enough zeaxanthin for the day.

While egg yolks are believed to be a good source, they do not contain nearly as much zeaxanthin as leafy greens.

Best time to take zeaxanthin

Since zeaxanthin is a fat-soluble carotenoid, it likely absorbs better when taken with a source of dietary fat.

Whether you take the supplement in the morning or the evening doesn’t really matter. It does not interrupt your sleep in any way.

Where to buy zeaxanthin?

Amazon seems to be the best option for ordering zeaxanthin supplements in most countries. They offer some very affordable products that are backed by many positive reviews. Also, you can choose from a wide range of brands there without having to spend time searching through other markets on the internet.

Beware that some brands display the dosage per serving and not per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.

FAQ

The supplement can be taken daily and does not need to be cycled.

All of these options are fine. The 2 most important things to consider are the price and dosing. Powders are almost always the cheapest form but to dose them correctly, you may need a highly accurate scale (preferably 0.001g). You can get one for as little as $20 from Amazon.

Yes. The carotenoid doesn’t impact your sleep in any negative way in the short term.

The supplements rarely go bad but they can lose potency over time.

Keep the supplements in a cold, dark, and dry place and they will remain just as potent for many years.

While toxicity is rare, too much of this carotenoid in the system could cause some health problems. Because of this, you want to stay below 20 mg a day.

The half-life of this antioxidant is around 16 hours. The nutrient stays in your system for about 3-4 days.

In the long-term, it typically takes around 4 weeks after you start taking the supplement to start noticing benefits.

Yes, the supplements are almost always vegan-friendly.

Since zeaxanthin is a carotenoid (a subgroup of vitamin A), it appears to be fat-soluble.

No, it doesn’t. The supplement does not interfere with fasting in any significant way.

References

Most of the information provided in this guide is based on scientific research that can be found and verified in the PubMed medical library. We excluded from consideration studies that are either confounded or have a high conflict of interest.

Anecdotal evidence (from reports on Reddit, YouTube, and other sources) is also taken into account unless it contradicts scientific research.

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