Astaxanthin, the icing on the longevity cake

In recent years, the price of astaxanthin has significantly fallen thanks to biotechnology, and the end of this price drop is not yet in sight. This means that life extensionists have an affordable supplement at their disposal, about which we do not yet know everything – but of which we can say with certainty that it has a broad spectrum of interesting anti-aging effects.

By Willem Koert


In December 2023, the scientific journal Geroscience published an animal study that received a lot of attention in the life extension movement. American aging researchers reported how they gave middle-aged mice astaxanthin and saw that the male animals lived an average of 12 percent longer as a result.[1]

The average age that the test animals in the control group could reach was 817 days. However, if the mice were given animal food enriched with astaxanthin, their average life span increased to 911 days.

Nevertheless, the study was a disappointment. The amount of astaxanthin the animals received was astronomical. Had the mice been adult men, they would have consumed 1200-1800 milligrams of astaxanthin per day. That is significantly more than the 0.2 milligrams per kilo of body weight per day that the European EFSA still considers acceptable.[2] For an adult man weighing 80 kilos, this amounts to 16 milligrams of astaxanthin per day.

The dose studied in Geroscience is also more than what consumers of supplements ingest during normal use. In most cases, these products provide 4-12 milligrams of astaxanthin per recommended daily intake.

On the other hand, the animal study confirmed what we already knew about astaxanthin: astaxanthin is safe, even in particularly high doses. And what we also already knew is that astaxanthin has a host of positive effects at much lower doses than the high dose studied in the Geroscience publication.

structure of astaxanthin


What is astaxanthin?

Astaxanthin, [structure shown above] like beta-carotene, lutein, and zeaxanthin, is a carotenoid. Like these other carotenoids, astaxanthin is a fat-soluble substance. For this reason, the supplement industry sometimes puts astaxanthin, dissolved in oleic acid or MCTs, in gel capsules, and supplement users can further increase astaxanthin absorption if they take their capsules with foods containing fat, such as nuts.

The best natural source of astaxanthin is the micro-algae Haematococcus pluvialis, but yeasts such as Pfaffia rhodozyma and bacteria such as Paracoccus carotinifaciens also produce astaxanthin. Salmon, shrimp, and lobster owe their purple color to astaxanthin. Although biotechnologists are looking with increasing interest at yeasts and molds to produce astaxanthin, there is much to be said for choosing Haematococcus pluvialis as a source of astaxanthin for the time being. One reason for this is that extracts from this alga contain not only astaxanthin, but also peptides with an anti-aging effect.[3] In this blog, we will not take this aspect into consideration.

In the body, astaxanthin molecules spread to all organs. Physiologists find them in the eyes, muscles, heart, blood vessel walls, joints, brain, and skin. There the molecules accumulate in the membranes of cells and mitochondria and, in combination with vitamins C and E, protect the cell against aggressive molecules in the cell and outside. The antioxidant effect of astaxanthin exceeds that of vitamins C and E by a factor of several hundred.



Thanks to its protective effect, astaxanthin extends the lifespan of yeast cells[4] and the nematode Caenorhabditis elegans.[5] Astaxanthin not only neutralizes aggressive molecules before they damage the cell, but also stimulates the cell to carry out repair processes and clean up poorly functioning mitochondria.

In nematodes, astaxanthin mimics the effect of caloric restriction by activating the gene daf-16, Chinese researchers reported in 2021.[6] Humans have an equivalent of that gene. It’s called FOXO3.

FOXO3 becomes active when the influence of hormones such as insulin and IGF-1 decreases while the activity of longevity genes such as SIRT1 increases. FOXO activates protective enzymes, shifts growth processes down a notch and repair processes up a notch.[7] FOXO3, together with APOE, is one of the two most important genetic factors that can slow down aging. Based on animal studies, researchers suspect that astaxanthin works by inhibiting FOXO3[8] and activating SIRT1[9] [10] [11] enhances the immune system,[12] helps clear cancer cells,[13] and protects against Parkinson’s disease,[14] and dementia.[15]


Human studies

We do not know to what extent astaxanthin as a supplement will fulfill all the above promises. There are no human studies yet that can tell us. On the other hand, a respectable number of trials have already been published that collectively show that astaxanthin in doses of 4-16 milligrams per day has a remarkably broad spectrum of positive health effects.


4 milligrams per day | protects the skin against UV light

Astaxanthin is a popular supplement among endurance athletes. Runners and cyclists use it not only because astaxanthin improves endurance performance (more about that later), but also because astaxanthin in a relatively small dose makes the skin more resistant to sunlight.[16] During long running or cycling sessions, the supplement reduces the chance of the skin burning. Occasionally, athletes even notice that they no longer need sunscreen when supplementing with astaxanthin.


6 milligrams per day | reduces wrinkles

Non-athletes can also benefit from the cosmetic effects of astaxanthin. That is not surprising, because exposure to UV light is an important factor in skin aging. According to a 2012 Japanese study, men who take a capsule containing 3 milligrams of astaxanthin after both breakfast and dinner reduce wrinkles at the corners of their eyes.[17] The supplementation had no effect on the deepest wrinkles but did reduce smaller wrinkles in 4-8 weeks. Because the skin became more elastic and better hydrated, even the smallest wrinkles disappeared completely.


6 milligrams per day | alleviates diabetes

When type-2 diabetics take 8 milligrams of astaxanthin daily for 8 weeks, their systolic blood pressure drops and the amount of glucose, triglycerides, and LDL (the ‘bad cholesterol’) in their blood decreases.[18] The effects are not overwhelmingly large, but according to diabetologists they may be clinically relevant.


8 milligram per day | stimulates immune system

Astaxanthin enables Natural Killer Cells, part of the first line of defense of the immune system, to neutralize more pathogens within 8 weeks.[19] At the same time, astaxanthin increases the activity of interferon-gamma, a signaling protein that stimulates immune cells to neutralize pathogens. Through this or another mechanism, astaxanthin softens the inhibitory effect of intensive physical exertion on the immune system. During and after exercise, fewer antibodies circulate in the body. Astaxanthin supplementation not only reduced the impact on the IgG and IgM antibodies, but also accelerated their return to normal levels.[20]


9 milligram per day | better vision

If you list the experiences of users, the positive effect of astaxanthin on vision is perhaps the most reported. Screen workers who have passed the age of forty notice that they can see more clearly. Japanese researchers saw this effect occur after just 6 weeks of supplementation.[21]


12 milligram per day | more endurance

Trained cyclists who take 12 milligrams of astaxanthin every day for 7 days improve their endurance.[22] During a 40K time trial, astaxanthin reduces their time by 1.2 percent. This equates to a time saving of 50 seconds. In the last part of intensive exercise, astaxanthin stimulates muscle cells to convert fatty acids into energy more easily, allowing them to save carbohydrates.


16 milligram per day | more fertile

If infertile men combine regular treatment for infertility with supplementation with astaxanthin, their chance of fatherhood increases by a factor of 5. This is evident from a small Belgian trial that lasted 3 months.[23] In the group of men who were treated exclusively in a regular manner, 11 percent of their partners eventually became pregnant. In the astaxanthin group this was 55 percent. The researchers suspect that the spermatozoa producing Sertoli cells started to function better after they incorporated astaxanthin molecules into their membranes.


Absence of side effects

The above list is not complete, but the message is clear: supplementation with normal doses has a broad spectrum of positive health effects. In addition, there is no evidence that astaxanthin has any significant side effects. In any case, in the trails serious adverse effects are conspicuous by their absence.

However, when cataloging user experiences on internet forums, we came across a side effect that we would like to mention here: some users noticed that their libido was reduced by astaxanthin. One theory circulating on the web is that astaxanthin inhibits the conversion of testosterone to the androgenic hormone dihydrotestosterone (DHT). This hormonal shift should explain the decrease in libido.

We have not been able to find confirmation for this theory. Although a few studies have been published in which supplements with astaxanthin lower the concentration of DHT in the blood of men – and at the same time increase that of testosterone – these supplements contain extracts of saw palmetto (Seranoa repens) in addition to astaxanthin.[24] [25] We know that the latter component reduces the biosynthesis of DHT.[26] So we wouldn’t be surprised if the reports of these side effects relate to supplements that contain not only astaxanthin, but also Seranoa repens.



No, there are no studies yet from which we can conclude that astaxanthin supplementation can extend human life span. Nevertheless, astaxanthin appears to be an interesting supplement for life extensionists. Astaxanthin already has a wide range of positive health effects, while, as research continues, more health effects are likely to emerge. And in addition, everything indicates that astaxanthin is exceptionally safe.




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[2] EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP); Bampidis V, Azimonti G, Bastos ML, Christensen H, Dusemund B, Kouba M, Kos Durjava M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M, Ramos F, Sanz Y, Villa RE, Woutersen R, Bories G, Brantom P, Renshaw D, Schlatter JR, Ackerl R, Holczknecht O, Steinkellner H, Vettori MV, Gropp J. Safety and efficacy of astaxanthin-dimethyldisuccinate (Carophyll® Stay-Pink 10%-CWS) for salmonids, crustaceans and other fish. EFSA J. 2019 Dec 18;17(12):e05920. [paragraph 3.2.5.]

[3] He W, Xie J, Xia Z, Chen X, Xiao J, Cao Y, Liu X. A novel peptide derived from Haematococcus pluvialis residue exhibits anti-aging activity in Caenorhabditis elegans via the insulin/IGF-1 signaling pathway. Food Funct. 2023 Jun 19;14(12):5576-88.

[4] Sj S, Veerabhadrappa B, Subramaniyan S, Dyavaiah M. Astaxanthin enhances the longevity of Saccharomyces cerevisiae by decreasing oxidative stress and apoptosis. FEMS Yeast Res. 2019 Jan 1;19(1).

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