Amount of Evidence: Reasonable Potential Benefits: Reasonable Safety: High
TABLE OF CONTENTS
What is astaxanthin?
Astaxanthin is a carotenoid with antioxidant properties. It is found primarily in fish and seafood and is the reason why many of those animals are pink or red. As a dietary supplement, astaxanthin is mainly used for improving vision and eye health. It can also be effective for reducing oxidation in the body, improving fertility, and a few other things. In this article, we will look at the main benefits of astaxanthin, 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
Reduced oxidation – Astaxanthin appears to have strong antioxidant effects. Supplementation of 4-20 mg has been shown to reduce general oxidation and lipid peroxidation. One study has also found a significant reduction in LDL oxidation. Also, doses as low as 5 mg have been shown to notably increase the antioxidant enzyme profile. More evidence is needed to show how significant this effect is.
Improved eye health – The antioxidant appears to notably increase ocular blood flow and a few other markers connected with eye health.
Minor benefits
Increased fertility – In one study, previously infertile men who were taking the carotenoid became fertile and had much higher birth rates than those who didn’t take the carotenoid. More research is needed to fully prove the effect on fertility.
Increased endurance – Some studies have noted a slight improvement in endurance in runners.
Improved skin quality – The antioxidant has been shown to improve skin elasticity and skin moisture, and reduce the roughness of the skin. Topical application and oral supplementation seem to have the same effect on skin quality.
Increased estrogen – One study found an increase in estradiol in menopausal women. This effect does not seem to apply to men.
Unproven benefits
The effect of astaxanthin on these parameters has either not been adequately researched, or the science shows little to no efficacy in these areas.
Reduced muscle damage – Only one study so far has found that astaxanthin could reduce muscle damage in very active individuals (soccer players in the case of this study). However, another study found no difference.
Blood glucose – Most studies show no effect of the antioxidant on blood glucose levels. However, the carotenoid may slightly lower blood glucose levels in type 2 diabetics and smokers. This has been shown by at least one study so far but more research is needed to prove this effect.
Blood flow – No significant change has ever been observed.
CRP (C-reactive protein) – Astaxanthin doesn’t seem to affect CRP.
Blood pressure – Only one study has shown that the carotenoid may slightly lower blood pressure in type 2 diabetics. 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, astaxanthin 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 – Astaxanthin 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 – Astaxanthin 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 astaxanthin 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.
Astaxanthin toxicity – The toxic dose is not yet known and may not even exist. As much as 50 mg at once or 6 mg over a prolonged period of time have 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 astaxanthin?
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
have a high budget for supplements (since astaxanthin will probably do more good than harm)
How much astaxanthin should you take?
The ideal dose of astaxanthin appears to be somewhere between 6-8 mg.
While you could safely take more than that (up to 50 mg have been shown to be safe), it is by no means necessary. Counter-intuitively, taking over 10 mg daily seems less effective than 6-8 mg. Higher amounts also increase the risk of unwanted side effects.
Food sources of astaxanthin
Red or pink fish, seafood, and flamingos contain the most astaxanthin. However, even those sources do not provide an optimal amount of the antioxidant unless you were to eat them in huge quantities, which is not a good idea for multiple reasons.
So the best way to get astaxanthin is through supplements.
Best time to take astaxanthin
Since astaxanthin is a 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 astaxanthin?
Amazon seems to be the best option for ordering astaxanthin 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.
One thing you should pay attention to is 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.
Yes. The nutrient doesn’t impact your sleep in any negative way in the short term.
Astaxanthin 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.
It doesn’t directly reduce acne but it does have multiple benefits as far as skin quality goes.
While astaxanthin 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.
In nature, this carotenoid is found primarily in pink or red fish and seafood. Unfortunately, the supplements are sometimes derived from these sources. However, many brands sell astaxanthin derived from algae, which is vegan-friendly.
Since astaxanthin 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.
