Table of ContentsView AllTable of ContentsUsesSide EffectsPrecautionsDosageToxicityInteractionsHow to StoreSimilar SupplementsFrequently Asked QuestionsSources & What to Look For
Table of ContentsView All
View All
Table of Contents
Uses
Side Effects
Precautions
Dosage
Toxicity
Interactions
How to Store
Similar Supplements
Frequently Asked Questions
Sources & What to Look For
Krill (shrimp-like crustaceans) contain omega-3 fatty acids that lower cholesterol and support heart health. Krill oil is also a source ofastaxanthin, an antioxidant that fights body-wide inflammation and helps prevent chronic health conditions.Both active ingredients may work together to improve knee osteoarthritis, but more research is needed to confirm this benefit.
The oils extracted from krill are often used in supplements because they contain two essential omega-3s you can only get from seafood:eicosapentaenoicacid (EPA) anddocosahexaenoicacid (DHA).
In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. Whenchoosing a supplement, look for independently tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
Uses of Krill
While more extensive research is necessary regarding effectiveness, people generally use krill to treat various health conditions.
Research is most robust for the following:
Supplement Facts
Heart Health
Some clinical trials have studied the effects of natural products—like krill—onheart diseaserisk factors, such ashigh cholesterolandhypertension (high blood pressure).
For example, a systematic review and meta-analysis (a methodical review and analysis of a collection of studies) included several krill oil–related studies that focused on cholesterol effects.
The results showed that krill oil loweredlow-density lipoprotein (LDL) cholesterol(“bad cholesterol”) andtriglycerides (TG).
Additionally, it was shown that krill oil also increasedhigh-density lipoprotein (HDL) cholesterol(“good cholesterol”), but lacked a significant effect ontotal cholesterollevels.
Per another study, a small clinical trial on the effects of krill powder in people with excess weight and moderately high blood pressure was conducted.
While the risk of side effects was low, krill powder didn’t significantly change blood pressure or cholesterol levels.
Overall, because results from both studies were mixed, further extensive research with more people is warranted.
Future clinical trials should also assess if krill’s potential effects on cholesterol and blood pressure also translate to positive heart-related outcomes.
Osteoarthritis Knee Pain
In a small six-month study, people with mild to moderate knee pain due toosteoarthritis (wear-and-tear arthritis)were divided into two groups—the krill andplacebogroups.
The krill group experienced more knee pain and stiffness relief than the placebo. There was also an improvement in knee physical function, such as walking.
While the study results were positive, further rigorous clinical trials that include a larger group of people are still warranted.
Premenstrual Syndrome
A small clinical trial studied the effects of a combination supplement that contains krill oil.
After three months of taking the daily supplement, the study participants experienced relief from severalPMSsymptoms.
Some of these symptoms include:
Although the results are promising, it isn’t easy to quantify the effects of krill oil. This study used a supplement that combined krill oil with other vitamins and natural products.
For this reason, future clinical trials should study krill oil separately to understand krill oil’s effects better.
Moreover, future research must include higher-quality, more extensive clinical trials.
Getty Images / Madeleine_Steinbach.
What Are the Side Effects of Krill?
Like many medications and natural products, krill supplements may have side effects.
Common Side Effects
Common side effects associated with the consumption of krill supplements may include:
Severe Side Effects
In a small study on krill powder, participants with excess weight and moderately high blood pressure didn’t experience severe side effects.
The FDA has placed krill on the GRAS (generally recognized as safe) list.
Still, a severe allergic reaction is a profound side effect possible with any medication or natural product.
If you’re having asevere allergic reaction, symptoms may include breathing difficulties, itchiness, and rash.
Additionally, krill is a rich source of omega-3 fatty acids, including eicosapentaenoic acid (EPA, a type of omega-3 fatty acid) and docosahexaenoic acid (DHA, a type of omega-3 fatty acid).
Because of this, high doses of EPA and DHA might result in the following serious side effects:
If you’re having a severe allergic reaction or if any of your symptoms feel life-threatening, call 911 and get medical help right away.
A healthcare provider may advise against krill if any of the following applies to you:
Severe allergic reaction: Avoid krill if you have a known allergy to it or its ingredients or parts. For example, avoid krill if you have a shellfish allergy.
For clarification on whether it’s safe, ask a registered dietitian, pharmacist, or healthcare provider for more information.
Pregnancy:In general, krill is a rich source of omega-3, which is an essential fatty acid that the body cannot make on its own.
Moreover, there are daily adequate intake (AI) amounts of omega-3 fatty acids for everyone, including those who arepregnant. AIs are used when isn’t enough evidence for recommended dietary allowances (RDAs) yet. The AI of omega-3 fatty acids for pregnant people is 1.4 grams (g).
Contact a healthcare provider to discuss the benefits, risks, and requirements when pregnant.
Breastfeeding: Krill is a source of omega-3, which is an essential fatty acid.There are AIs of omega-3 fatty acids forbreastfeedingparents. The AI of omega-3 fatty acids for breastfeeding parents is 1.3 g.
Reach out to a healthcare provider to discuss the benefits, risks, and requirements when breastfeeding.
Adults over 65: Older adults have participated in some studies on krill, a rich source of omega, an essential fatty acid called omega-3.There are also AIs of omega-3 fatty acids for people older than 50.
For males, the AI is 1.6 g for this age group. And for females, the AI is 1.1 g.
In general, use krill cautiously. Some older adults may have a higher likelihood of side effects from medications.
Children: Krill is rich in omega-3, an essential fatty acid.
There are AIs of omega-3 fatty acids for children of various ages:
But once your child is at least 9 years old, the AIs slightly change depending on your child’s sex:
Talk with a healthcare provider if you’re considering krill for your child.
Dosage: How Much Krill Should I Use?
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
Krill is rich in omega-3, an essential fatty acid the body cannot make alone.
AI is an amount of vitamin, mineral, or fatty acid assumed to be enough to meet nutritional needs. These AIs may vary based on age, sex, pregnancy, and breastfeeding status.
However, in clinical trials that studied the potential effects of krill, the dosage forms varied.
In studies with krill oil, the amount of krill oil and specific amounts of the EPA and DHA omega-3 fatty acids also differed.
A clinical trial also combined krill oil with other vitamins and natural products.In general, additional rigorous research with higher-quality, larger studies is warranted
For these reasons, there are no guidelines on the appropriate dosage to take krill supplements for any condition. But for cholesterol effects, many studies used krill in a 500 milligram (mg) capsule form with krill oil dosages varying between 1 g and 3 g per day.
What Happens If I Use Too Much Krill?
Krill is rich in omega-3 fatty acids, primarily EPA and DHA.
At high doses of EPA and DHA, you might experience the following:
If you suspect you are experiencing life-threatening side effects from too much krill, seek immediate medical attention.
Krill might interact with the following medications:
It is essential to carefully read a supplement’s ingredients list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review the supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.
How to Store Krill
Storage instructions may vary for different products. Carefully read the directions and packaging label on the container.
Generally, most medicines' optimal storage condition is in a cool and dry place. You should also keep your medications tightly closed and out of the reach of children and pets, ideally locked in a cabinet or closet.
Discard after one year or as indicated on the packaging. Avoid putting unused and expired products down the drain or in the toilet. Visit the FDA website to know where and how to discard all unused and expired medications.
You can also find disposal boxes in your area.
Ask a pharmacist or healthcare provider if you have any questions about how to dispose of your medications or natural products.
If you plan totravelwith krill, get familiar with your final destination’s regulations. TheU.S. Embassy & Consulatescan be a helpful resource.
Ask a healthcare provider how to travel with your medications or natural products if necessary…
Krill may affect high cholesterol for heart health, osteoarthritis, knee pain, and PMS.
Other similar supplements include:
Only combine multiple natural products once you first talk with a healthcare provider, pharmacist, or dietitian. Checking in can help you avoid possible harmful interactions and side effects and ensure you’re giving these supplements a fair trial at appropriate doses.
Frequently Asked QuestionsKrill supplements are available in a few different dosage forms—with capsules being the most common.Yes. Manufacturers in the United States make krill supplements.To safely take natural products—like krill—inform your healthcare providers and pharmacists about any medication changes. This includes over-the-counter (OTC), herbal, natural medicines, and supplements.Your healthcare provider can help prevent possible interactions and side effects. They can also ensure you’re giving krill a fair trial at appropriate doses.
Krill supplements are available in a few different dosage forms—with capsules being the most common.
Yes. Manufacturers in the United States make krill supplements.
To safely take natural products—like krill—inform your healthcare providers and pharmacists about any medication changes. This includes over-the-counter (OTC), herbal, natural medicines, and supplements.Your healthcare provider can help prevent possible interactions and side effects. They can also ensure you’re giving krill a fair trial at appropriate doses.
To safely take natural products—like krill—inform your healthcare providers and pharmacists about any medication changes. This includes over-the-counter (OTC), herbal, natural medicines, and supplements.
Your healthcare provider can help prevent possible interactions and side effects. They can also ensure you’re giving krill a fair trial at appropriate doses.
Sources of Krill & What to Look For
There are a few different sources of krill. Health nutrition guidelines typically prioritize food sources to improve the diet. While food sources are preferable, there might still be a place for supplements for certain groups of people, such as those with certain medical conditions.
Food Sources of Krill
Krill is a tiny shrimp-like water-living animal.The U.S. Department of Agriculture (USDA) considers krill a food.
Krill Supplements
Krill supplements are commonly available in capsule form.
Other dosage forms of krill may include:
But some of these other forms might also contain other ingredients.
What you decide on will depend on your preference and what you hope to receive regarding health benefits. Each product may work a bit differently, depending on the form.
So, following a healthcare provider’s recommendations or label directions is essential.
Summary
Krill is a tiny shrimp-like water-living animal. As a source of omega-3 fatty acids and astaxanthin, krill may have some potential uses in high cholesterol for heart health, osteoarthritis, knee pain, and PMS. Before using krill, get the advice of a registered dietitian, pharmacist, or healthcare provider to help you decide if krill is right for you.
21 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Bjørklund G, Gasmi A, Lenchyk L, et al.The Role of Astaxanthin as a Nutraceutical in Health and Age-Related Conditions.Molecules. 2022 Oct 23;27(21):7167. doi:10.3390/molecules27217167.National Institutes of Health: Office of Dietary Supplements.Omega-3 fatty acids.Ursoniu S, Sahebkar A, Serban MC, et al.Lipid-modifying effects of krill oil in humans: systematic review and meta-analysis of randomized controlled trials.Nutr. 2017;75(5):361-373. doi:10.1093/nutrit/nuw063Backes JM, Howard PA.Krill oil for cardiovascular risk prevention: Is it for real?.Hosp Pharm. 2014;49(10):907-12. doi:10.1310/hpj4910-907United States Department of Agriculture.FoodData Central: krill.National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: krill.Sarkkinen ES, Savolainen MJ, Taurio J, et al.Prospective, randomized, double-blinded, placebo-controlled study on safety and tolerability of the krill powder product in overweight subjects with moderately elevated blood pressure.Lipids Health Dis. 2018;17(287). doi:10.1186/s12944-018-0935-xNational Institutes of Health: Office of Dietary Supplements.Omega-3 fatty acids: fact sheet for health professionals.Driscoll DF.Potentially important therapeutic interactions between antibiotics, and a specially engineered emulsion drug vehicle containing krill-oil-based phospholipids and omega-3 fatty acids.Antibiotics (Basel). 2018;7(1):22. doi:10.3390/antibiotics7010022Stonehouse W, Benassi-Evans B, Bednarz J, et al.Krill oil improved osteoarthritis knee pain in adults with mild to moderate knee osteoarthritis: a 6-month multicenter, randomized, double-blind, placebo-controlled trial.Am J Clin Nutr. 2022;116(3):672-685. doi:10.1093/ajcn/nqac125Wakeman MP.An open-label pilot sutdy to assess the effectiveness of krill oil with added vitamins and phytonutrients in the relief of symptoms of PMS.Nutr DIet Suppl. 2013;5:17-25. doi:10.2147/NDS.S48133Food and Drug Administration.GRAS notices: krill.MedlinePlus.Omega-3 fatty acids.Food and Drug Administration.Where and how to disposed of unused medicines.National Association Boards of Pharmacy.Drug disposal.USEmbassy.gov.Home.National Center for Complementary and Integrative Health.6 things you should know about dietary supplements for osteoarthritis.National Center for Complementary and Integrative Health.Chasteberry.National Center for Complementary and Integrative Health.Cardiovascular disease.MedlinePlus.A guide to herbal remedies.Lentjes MAH.The balance between food and dietary supplements in the general population.Proc Nutr Soc. 2019;78(1):97-109. doi:10.1017%2FS0029665118002525
21 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Bjørklund G, Gasmi A, Lenchyk L, et al.The Role of Astaxanthin as a Nutraceutical in Health and Age-Related Conditions.Molecules. 2022 Oct 23;27(21):7167. doi:10.3390/molecules27217167.National Institutes of Health: Office of Dietary Supplements.Omega-3 fatty acids.Ursoniu S, Sahebkar A, Serban MC, et al.Lipid-modifying effects of krill oil in humans: systematic review and meta-analysis of randomized controlled trials.Nutr. 2017;75(5):361-373. doi:10.1093/nutrit/nuw063Backes JM, Howard PA.Krill oil for cardiovascular risk prevention: Is it for real?.Hosp Pharm. 2014;49(10):907-12. doi:10.1310/hpj4910-907United States Department of Agriculture.FoodData Central: krill.National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: krill.Sarkkinen ES, Savolainen MJ, Taurio J, et al.Prospective, randomized, double-blinded, placebo-controlled study on safety and tolerability of the krill powder product in overweight subjects with moderately elevated blood pressure.Lipids Health Dis. 2018;17(287). doi:10.1186/s12944-018-0935-xNational Institutes of Health: Office of Dietary Supplements.Omega-3 fatty acids: fact sheet for health professionals.Driscoll DF.Potentially important therapeutic interactions between antibiotics, and a specially engineered emulsion drug vehicle containing krill-oil-based phospholipids and omega-3 fatty acids.Antibiotics (Basel). 2018;7(1):22. doi:10.3390/antibiotics7010022Stonehouse W, Benassi-Evans B, Bednarz J, et al.Krill oil improved osteoarthritis knee pain in adults with mild to moderate knee osteoarthritis: a 6-month multicenter, randomized, double-blind, placebo-controlled trial.Am J Clin Nutr. 2022;116(3):672-685. doi:10.1093/ajcn/nqac125Wakeman MP.An open-label pilot sutdy to assess the effectiveness of krill oil with added vitamins and phytonutrients in the relief of symptoms of PMS.Nutr DIet Suppl. 2013;5:17-25. doi:10.2147/NDS.S48133Food and Drug Administration.GRAS notices: krill.MedlinePlus.Omega-3 fatty acids.Food and Drug Administration.Where and how to disposed of unused medicines.National Association Boards of Pharmacy.Drug disposal.USEmbassy.gov.Home.National Center for Complementary and Integrative Health.6 things you should know about dietary supplements for osteoarthritis.National Center for Complementary and Integrative Health.Chasteberry.National Center for Complementary and Integrative Health.Cardiovascular disease.MedlinePlus.A guide to herbal remedies.Lentjes MAH.The balance between food and dietary supplements in the general population.Proc Nutr Soc. 2019;78(1):97-109. doi:10.1017%2FS0029665118002525
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Bjørklund G, Gasmi A, Lenchyk L, et al.The Role of Astaxanthin as a Nutraceutical in Health and Age-Related Conditions.Molecules. 2022 Oct 23;27(21):7167. doi:10.3390/molecules27217167.National Institutes of Health: Office of Dietary Supplements.Omega-3 fatty acids.Ursoniu S, Sahebkar A, Serban MC, et al.Lipid-modifying effects of krill oil in humans: systematic review and meta-analysis of randomized controlled trials.Nutr. 2017;75(5):361-373. doi:10.1093/nutrit/nuw063Backes JM, Howard PA.Krill oil for cardiovascular risk prevention: Is it for real?.Hosp Pharm. 2014;49(10):907-12. doi:10.1310/hpj4910-907United States Department of Agriculture.FoodData Central: krill.National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: krill.Sarkkinen ES, Savolainen MJ, Taurio J, et al.Prospective, randomized, double-blinded, placebo-controlled study on safety and tolerability of the krill powder product in overweight subjects with moderately elevated blood pressure.Lipids Health Dis. 2018;17(287). doi:10.1186/s12944-018-0935-xNational Institutes of Health: Office of Dietary Supplements.Omega-3 fatty acids: fact sheet for health professionals.Driscoll DF.Potentially important therapeutic interactions between antibiotics, and a specially engineered emulsion drug vehicle containing krill-oil-based phospholipids and omega-3 fatty acids.Antibiotics (Basel). 2018;7(1):22. doi:10.3390/antibiotics7010022Stonehouse W, Benassi-Evans B, Bednarz J, et al.Krill oil improved osteoarthritis knee pain in adults with mild to moderate knee osteoarthritis: a 6-month multicenter, randomized, double-blind, placebo-controlled trial.Am J Clin Nutr. 2022;116(3):672-685. doi:10.1093/ajcn/nqac125Wakeman MP.An open-label pilot sutdy to assess the effectiveness of krill oil with added vitamins and phytonutrients in the relief of symptoms of PMS.Nutr DIet Suppl. 2013;5:17-25. doi:10.2147/NDS.S48133Food and Drug Administration.GRAS notices: krill.MedlinePlus.Omega-3 fatty acids.Food and Drug Administration.Where and how to disposed of unused medicines.National Association Boards of Pharmacy.Drug disposal.USEmbassy.gov.Home.National Center for Complementary and Integrative Health.6 things you should know about dietary supplements for osteoarthritis.National Center for Complementary and Integrative Health.Chasteberry.National Center for Complementary and Integrative Health.Cardiovascular disease.MedlinePlus.A guide to herbal remedies.Lentjes MAH.The balance between food and dietary supplements in the general population.Proc Nutr Soc. 2019;78(1):97-109. doi:10.1017%2FS0029665118002525
Bjørklund G, Gasmi A, Lenchyk L, et al.The Role of Astaxanthin as a Nutraceutical in Health and Age-Related Conditions.Molecules. 2022 Oct 23;27(21):7167. doi:10.3390/molecules27217167.
National Institutes of Health: Office of Dietary Supplements.Omega-3 fatty acids.
Ursoniu S, Sahebkar A, Serban MC, et al.Lipid-modifying effects of krill oil in humans: systematic review and meta-analysis of randomized controlled trials.Nutr. 2017;75(5):361-373. doi:10.1093/nutrit/nuw063
Backes JM, Howard PA.Krill oil for cardiovascular risk prevention: Is it for real?.Hosp Pharm. 2014;49(10):907-12. doi:10.1310/hpj4910-907
United States Department of Agriculture.FoodData Central: krill.
National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: krill.
Sarkkinen ES, Savolainen MJ, Taurio J, et al.Prospective, randomized, double-blinded, placebo-controlled study on safety and tolerability of the krill powder product in overweight subjects with moderately elevated blood pressure.Lipids Health Dis. 2018;17(287). doi:10.1186/s12944-018-0935-x
National Institutes of Health: Office of Dietary Supplements.Omega-3 fatty acids: fact sheet for health professionals.
Driscoll DF.Potentially important therapeutic interactions between antibiotics, and a specially engineered emulsion drug vehicle containing krill-oil-based phospholipids and omega-3 fatty acids.Antibiotics (Basel). 2018;7(1):22. doi:10.3390/antibiotics7010022
Stonehouse W, Benassi-Evans B, Bednarz J, et al.Krill oil improved osteoarthritis knee pain in adults with mild to moderate knee osteoarthritis: a 6-month multicenter, randomized, double-blind, placebo-controlled trial.Am J Clin Nutr. 2022;116(3):672-685. doi:10.1093/ajcn/nqac125
Wakeman MP.An open-label pilot sutdy to assess the effectiveness of krill oil with added vitamins and phytonutrients in the relief of symptoms of PMS.Nutr DIet Suppl. 2013;5:17-25. doi:10.2147/NDS.S48133
Food and Drug Administration.GRAS notices: krill.
MedlinePlus.Omega-3 fatty acids.
Food and Drug Administration.Where and how to disposed of unused medicines.
National Association Boards of Pharmacy.Drug disposal.
USEmbassy.gov.Home.
National Center for Complementary and Integrative Health.6 things you should know about dietary supplements for osteoarthritis.
National Center for Complementary and Integrative Health.Chasteberry.
National Center for Complementary and Integrative Health.Cardiovascular disease.
MedlinePlus.A guide to herbal remedies.
Lentjes MAH.The balance between food and dietary supplements in the general population.Proc Nutr Soc. 2019;78(1):97-109. doi:10.1017%2FS0029665118002525
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