Does Astaxanthin Have Side Effects? Here's Everything You Need to Know

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    Review of astaxanthin side effects to find out if the antioxidant properties of astaxanthin are helpful or harmful to the kidney, liver, and hormones.

    Let’s talk about astaxanthin side effects. While astaxanthin has grown in popularity over the years, the name may still be new to you. Don’t let that X in the middle throw you off. Astaxanthin is pronounced “asta” (like pasta) “zan-thin”.

    But what exactly is astaxanthin? A plant? An animal? A bizarre new diet fad? It’s actually none of the above!

    What is astaxanthin?

    Astaxanthin is a red pigment. You know how the pigment beta-carotene makes carrots orange? Well, astaxanthin makes foods red. In fact, it’s responsible for the red and pink colors of salmon and algae.

    Natural food sources of astaxanthin include marine sources like algae, crayfish, krill, salmon, and shrimp. Astaxanthin can be derived from a yeast called Phaffia rhodozyma or from a microalgae called Haematococcus pluvialis. Extracted astaxanthin can be found in dietary supplements.

    Astaxanthin is a carotenoid, like beta-carotene. We know that carotenoids are antioxidants and may have certain health benefits. The body makes substances called “free radicals” as a result of normal functions like breathing or exercise. Antioxidants help protect cells from the damage that free radicals can do.

    Does astaxanthin have side effects?

    Using astaxanthin as a dietary supplement may have certain beneficial side effects, according to research. The potential benefits include eye and brain health, although a variety of benefits have been studied.

    As we review the topic of astaxanthin side effects, we will focus on both the positive and any potential negative side effects.

    Are there any risks to taking astaxanthin?

    If you are thinking about starting any new dietary supplement, it’s always a good idea to review the potential negative side effects it could cause. This can help you keep an eye out for these concerns.

    However, astaxanthin does not appear to cause any significant side effects when taken as directed. The clinical trials we will review did not report safety issues.

    A review of astaxanthin suggests that it may have a negative impact on adaptations to exercise. However, it’s important to note that this would likely only be at high doses.

    As we’ve discussed, astaxanthin is an antioxidant that protects against oxidative stress. When we exercise, the body is put under stress and has to adapt. Astaxanthin, or any antioxidant, can help fight against this stress. Since antioxidants are protective against stress from exercise, antioxidants could prevent the body from adapting to exercise. But again, this would only be at excessive doses.

    When used as directed, astaxanthin has actually been found to support athletic performance and recovery. Therefore, it’s a good idea to only take astaxanthin (or any antioxidant supplement) at the recommended dose to prevent any potential impacts on exercise performance.

    Astaxanthin is a carotenoid and very high intakes of carotenoids can cause your skin to turn orange. (At doses above 30 mg taken for an extended period of time) This is just one more reason why it’s essential to only use carotenoids like astaxanthin as directed.

    We will cover the specifics on choosing the right dose of astaxanthin a little later. But let’s first review any potential issues from taking astaxanthin.

    Astaxanthin and liver health

    When researching the side effects of supplements, you may have concerns about the impact of astaxanthin on liver health. Supplement ingredients that are absorbed by the digestive system must pass through your liver. So you do not want to take anything that could be harmful to the liver.

    No need to be concerned about astaxanthin and liver health!

    In fact, research has actually shown that astaxanthin may help support liver health. We won’t get into all the nerdy metabolic pathways that astaxanthin can impact (if that’s your thing, you can read the full review article here).

    In summary, the antioxidant properties of astaxanthin play a role in promoting a healthy liver. Cell and animal studies show promising results and we look forward to more research into this exciting area of health!

    Astaxanthin and kidney health

    Both the kidney and the liver are essential for detox! We’re not talking about detox fads, but the process of detoxification that your body must do to stay healthy. The kidneys filter your blood and remove wastes. If there is something in the blood that could be harmful to the kidneys, it could have a negative impact on kidney function. But if a substance is beneficial to the kidneys, then consuming it so it gets into the bloodstream can have a positive impact!

    Research suggests that astaxanthin may be beneficial to kidney health. Since it can act as a powerful antioxidant, it could have a protective effect on the kidneys.

    Oxidative stress has been found to have a negative impact on kidney health. Remember the free radicals we discussed above that can damage cells? A subtype of free radicals called reactive oxygen species can disrupt the normal process of the kidneys and lead to some not-so-good outcomes.

    Animal studies have found that astaxanthin may help with this oxidative stress and support kidney health.

    Human trials will be needed to find out more. But these studies only point to potential benefits of astaxanthin on kidney health, and did not uncover any negative impacts.

    Astaxanthin and hormonal health

    Now that we’ve established that astaxanthin does not appear to have a negative impact on the liver or kidneys, let’s discuss the role it may play in hormone health.

    Are you concerned that astaxanthin may affect your hormones? You may be right, but there is no cause for concern!

    A cell study found that astaxanthin was protective to reproductive cells. This is because it can protect cells from oxidative stress (are you seeing a pattern here?)

    An animal study found astaxanthin to be beneficial for the healthy aging of ovaries, an important piece of the reproductive system. The study also found that astaxanthin supported a healthy balance of reproductive hormones.

    A cell study found that astaxanthin increased progesterone. This should not be a concern, though. Having a healthy level of progesterone is mostly beneficial, no matter who you are. This can be further supported by a human study which found that astaxanthin supports healthy fertility.

    Is there anyone who should not take astaxanthin?

    Since the research on astaxanthin is continuing to grow, it’s best for those who are pregnant or nursing to avoid taking it as a dietary supplement at this time. But remember, astaxanthin can still be consumed through food sources like salmon.

    Research suggests that astaxanthin may support healthy blood pressure levels already within normal range. If you are taking prescribed medication always talk to your healthcare provider before starting a new supplement.

    What is the right dosage for taking astaxanthin?

    Most of the studies looking at the benefits of astaxanthin as a dietary supplement used 6 to 8 mg per day. However, the recommended dosage can vary by country and has been found to range between 2 and 24 mg per day.

    We’ve already discussed that astaxanthin is likely safe and has few side effects when taken as directed. One trial suggested that up to 6 mg per day is safe.

    What to look for in an astaxanthin supplement

    If you’re ready to add an astaxanthin supplement to your routine, look for one that is third-party tested to confirm that you are getting the dose and ingredients promised on the label.

    Researchers note that synthetic astaxanthin is chemically different from synthetic astaxanthin. Few safety studies have been done on synthetic astaxanthin. Therefore, it’s best to choose a natural form of astaxanthin!

    Our astaxanthin is natural and sustainability harvested from phototropic, Himalayan water-fed algae. We work with one of the few suppliers in the Natural Algae Astaxanthin Association, who set the standard for astaxanthin quality.

    Key takeaways

    Astaxanthin is a carotenoid that is mostly found in marine sources. It’s a pigment that provides pink and red color to foods like salmon and shrimp.

    Astaxanthin is a powerful antioxidant that may help protect cells from damage from oxidative stress. It does not appear to have a negative impact on the liver, kidney, or hormone health. In fact, astaxanthin may help support the health of these body systems. It may also play a role in eye and brain health.

    It’s important to only use astaxanthin as directed and choose a natural form from a reputable source.

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    Dr. Carla Montrond Correia ND, CNS
    Medical Content Manager
    Dr. Montrond-Correia is a licensed naturopathic physician and a certified nutrition specialist (CNS). She holds degrees from University of Bridgeport, Georgetown University, and University of Saint Joseph, and supplemented her education with internships in the health and wellness space. She's focused on research, herbal medicine, nutrigenomics, and integrative and functional medicine. She makes time for exercise, artistic activities, and enjoying delicious food.
    Our Editorial Staff
    Freelance Contributor
    The Care/of Editorial Team is made up of writers, experts, and health enthusiasts, all dedicated to giving you the information you need today. Our team is here to answer your biggest wellness questions, read the studies for you, and introduce you to your new favorite product, staying up to date on the latest research, trends, and science. Each article is written by one of our experts, reviewed both for editorial standards by an editor and medical standards by one of our naturopathic doctors, and updated regularly as new information becomes available.