Table of ContentsView AllTable of ContentsBenefitsTypesIndicationsSide EffectsSafety
Table of ContentsView All
View All
Table of Contents
Benefits
Types
Indications
Side Effects
Safety
Both over-the-counter (OTC) and prescription fish oil supplements contain omega-3 fatty acids, the “good” fats in fish that can help reduce triglyceride levels. However, prescription formulations have significantly higher active compound concentrations and typically are given only to manage very high triglyceride levels.
In the United States, the Food and Drug Administration (FDA) regulates prescription fish oil supplements but not OTC ones. That means some OTC 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.
Verywell / Anastasia Tretiak
The Benefits of Fish Oil
Omega-3 fatty acids are a type of “good"polyunsaturated fats. They include bioactive fatty acids known as:
Omega-3 fatty acids are thought to offer manyhealth benefits:
While omega-3s are found in fatty fish (such as salmon and mackerel) and other foods, they come in much higher amounts in OTC and prescription fish oil supplements.
OTC Omega-3 Supplements
OTC omega-3 supplements contain ample quantities of ALA but comparatively low levels of DHA and EPA. The problem with this is that EPA is the compound known to reduce vascular inflammation (which contributes to atherosclerosis), while DHA is the compound that exerts the greatest impact on triglycerides.
While ALA has positive effects on bloodlipids(fats), DHA and EPA appear to be the compounds that can deliver actual “heart-healthy” benefits. Even so, the benefits of OTC fish oil supplements remain largely unproven.
What Current Research SaysClinical studies have yet to show that OTC fish oil supplements are able to lower the risk of heart disease or stroke. Most studies have concluded that they offer no benefit.
What Current Research Says
Clinical studies have yet to show that OTC fish oil supplements are able to lower the risk of heart disease or stroke. Most studies have concluded that they offer no benefit.
Prescription Fish Oil Supplements
Types of Omega-3 Supplements
There are other key differences in the composition and production of OTC vs. prescription fish oil supplements
OTC omega-3 supplements found in stores are commonly made from fish oil but can also be derived from other marine animals (such as krill) and occasionally sea plants (like algae). Based on the medium used, the concentration of DHA and EPA can vary from one OTC supplement to the next.
Interestingly, fish oil tends to have less DHA and EPA than either krill oralgae oileven though it is the most common omega-3 supplement. Similarly, the DHA and EPA content in krill oil has greater bioavailability (meaning the proportion of drug entering the bloodstream) than either fish or algae oil.
Prescription Fish Oil
Research has shown that the benefits of DHA and EPA are dose-dependent, meaning that better results are received at higher doses. And, until you reach a certain threshold, you may get no benefit at all.
With DHA, for example, you need to take around 600 milligrams (mg) per day to achieve a 20% drop in triglycerides. Lesser doses do little to alter triglyceride levels.
And this is a problem because OTC supplements only deliver 120 mg of DHA per dose (and often far less because supplements in the United States are not strictly regulated).
Another issue is that high doses of EPA may enhance the triglyceride-lowering effects of DHA but also increase levels of “bad"LDL cholesterolthat clog arteries. As such, getting more and more EPA may end up increasing—rather than lowering—the risk of atherosclerosis, particularly in those with uncontrolledhigh cholesterol.
There are two prescription omega-3 drugs approved for use in the United States include:
Why Do I Need Prescription Fish Oil?
The main difference between OTC and prescription supplements is that OTC supplements are not approved to prevent, treat, or manage any medical condition. While OTC supplements are generally regarded as safe, their benefits are often presumed rather than proven.
Generic forms are available.
Over-the-Counter Omega-3 Supplements
There are no indications for the use of OTC omega-3 supplements and no recommended dose. As a general rule, never exceed the dose listed on the manufacturer’s label.
Because OTC and prescription fish oil supplements contain more or less the same ingredients, you can take 10 or 12 OTC supplements to get the right amount of DHA and EPA. And you’ll likely lower your triglycerides in the same way.
But the problem with this is twofold:
To avoid such problems, speak with your healthcare provider before starting any new supplement. Self-treating any medical condition may end up causing more harm than good.
You can take more OTC supplements to match a prescription dose, but this can cause side effects and even lead to an increase in “bad"LDL cholesterol.
Potential Side Effects and Risks
Both OTC and prescription fish oil supplements can cause side effects such as burping, heartburn, and joint pain, particularly if they’re taken in excessive quantities. OTC fish oil supplements, however, come with a few more.
Other possible side effects of OTC omega-3 supplements include:
If taken in excess, fish oil can affect blood clotting and increase bruising and bleeding. Even so, studies suggest that doses of up to 10,000 mg per day may be safe for short-term use with no significant impact on blood clotting.
FDA RecommendationsThe FDA currently recommends taking no more than 2 grams (2,000 mg) of OTC fish oil supplements a day unless it is under the guidance of a healthcare provider.
FDA Recommendations
The FDA currently recommends taking no more than 2 grams (2,000 mg) of OTC fish oil supplements a day unless it is under the guidance of a healthcare provider.
Lovaza and Vascepa can cause many of the same side effects as their OTC counterparts, but they do so at therapeutic doses. The most common side effects are burping, upset stomach, and changes in taste).
It is not known if Lovaza and Vascepa can cause allergies in people who are allergic to fish or shellfish. If you have a known fish or shellfish allergy, speak with your healthcare provider before using either supplement.
Safety and Purity
Prescription drugs are regulated more stringently. To be approved, the product must undergo extensive lab, animal, and human testing to ensure that it is safe and effective for different populations of adults or children.
In addition to indications of use, the FDA will list contraindications (meaning when or in whom the drug cannot be used). Information about recommended dosage and storage will be included.
Prescription fish oil supplements should be stored at 77 F (25 C). Short excursions in temperature between 59 F and 86 F (15 C and 30 C) are acceptable. Discard any expired medications. Keep out of the reach of children and pets.
Summary
Over-the-counter and prescription fish oil supplements contain more or less the same ingredients. But prescription supplements like Lovaza and Vascepa contain higher amounts of compounds DHA and EPA that are known to reduce triglycerides. You can increase the number of OTC supplements to reach the same dose but would likely increase the risk of side effects.
The FDA says that you should not take more than 2 grams (2,000 mg) of OTC fish oil supplements a day unless under the direction of a healthcare provider.
10 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.National Institutes of Health.Omega-3 fatty acids.Hilleman DE, Wiggins BS, Bottorff MB.Critical differences between dietary supplement and prescription omega-3 fatty acids: a narrative review.Adv Ther. 2020;37(2):656-670. doi:10.1007/s12325-019-01211-1Khoukaz HB, Fay WP.Fish oil supplements for prevention of cardiovascular disease: the jury is still out.Mo Med.2021 May-Jun;118(3):219–25.Asztalos IB, Gleason JA,Sever W, et al.Effects of eicosapentaenoic acid and docosahexaenoic acid on cardiovascular disease risk factors: a randomized clinical trial.Metabol Clin Exper. 2016:65(11):1636–45. doi:10.1016/j.metabol.2016.07.010GlaxoSmithKline.Lovazo (omega-3-acid ethyl esters) capsules, for oral use.GlaxoSmithKline.Vascepa (icosapent ethyl) capsules, for oral use.Skulas-Ray AC, Wilson PWF, Harris WS, et al.Omega-3 fatty acids for the management of hypertriglyceridemia: a science advisory from the American Heart Association.Circulation. 2019;140(12):e673-e691. doi:10.1161/CIR.0000000000000709MedlinePlus.Omega-3 fatty acids.Jeansen S, Witkamp RF, Garthoff JA, van Helvoort A, Calder PC.Fish oil LC-PUFAs do not affect blood coagulation parameters and bleeding manifestations: analysis of 8 clinical studies with selected patient groups on omega-3-enriched medical nutrition.Clin Nutr.2018 Jun;37(3):948-57. doi:10.1016/j.clnu.2017.03.027Food and Drug Administration.Dietary supplements.Additional ReadingScientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA).EFSA Journal. 2012;10(7). doi:10.2903/j.efsa.2012.2815Amminger GP, Nelson B, Markulev C, Yuen HP, Schäfer MR, Berger M, Mossaheb N, Schlögelhofer M, Smesny S, Hickie IB, Berger GE, Chen EYH, de Haan L, Nieman DH, Nordentoft M, Riecher-Rössler A, Verma S, Thompson A, Yung AR, McGorry PD.The NEURAPRO biomarker analysis: Long-chain omega-3 fatty acids improve 6-month and 12-month outcomes in youths at ultra-high risk for psychosis.Biol Psychiatry. 2019. doi:10.1016/j.biopsych.2019.08.030Bradberry JC, Hilleman DE.Overview of omega-3 fatty acid therapies.P T. 2013;38(11). PMID: 24391388; PMCID: PMC3875260.Chitre NM, Moniri NH, Murnane KS.Omega-3 fatty acids as druggable therapeutics for neurodegenerative disorders.CNS Neurol Disorders—Drug Targets. 2019. doi:10.2174/1871527318666191114093749Ito MK.A comparative overview of prescription omega-3 fatty acid products.P&T: a peer-reviewed journal for formulary management. 2015;40(12):826-57. PMID: 26681905; PMCID: PMC4671468.Jain AP, Aggarwal KK, Zhang PY.Omega-3 fatty acids and cardiovascular disease.European Review for Medical and Pharmacological Sciences. 2015;19(3):441–445.Patrick RP, Ames BN.Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior.FASEB J. 2015;29(6). doi:10.1096/fj.14-268342
10 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.National Institutes of Health.Omega-3 fatty acids.Hilleman DE, Wiggins BS, Bottorff MB.Critical differences between dietary supplement and prescription omega-3 fatty acids: a narrative review.Adv Ther. 2020;37(2):656-670. doi:10.1007/s12325-019-01211-1Khoukaz HB, Fay WP.Fish oil supplements for prevention of cardiovascular disease: the jury is still out.Mo Med.2021 May-Jun;118(3):219–25.Asztalos IB, Gleason JA,Sever W, et al.Effects of eicosapentaenoic acid and docosahexaenoic acid on cardiovascular disease risk factors: a randomized clinical trial.Metabol Clin Exper. 2016:65(11):1636–45. doi:10.1016/j.metabol.2016.07.010GlaxoSmithKline.Lovazo (omega-3-acid ethyl esters) capsules, for oral use.GlaxoSmithKline.Vascepa (icosapent ethyl) capsules, for oral use.Skulas-Ray AC, Wilson PWF, Harris WS, et al.Omega-3 fatty acids for the management of hypertriglyceridemia: a science advisory from the American Heart Association.Circulation. 2019;140(12):e673-e691. doi:10.1161/CIR.0000000000000709MedlinePlus.Omega-3 fatty acids.Jeansen S, Witkamp RF, Garthoff JA, van Helvoort A, Calder PC.Fish oil LC-PUFAs do not affect blood coagulation parameters and bleeding manifestations: analysis of 8 clinical studies with selected patient groups on omega-3-enriched medical nutrition.Clin Nutr.2018 Jun;37(3):948-57. doi:10.1016/j.clnu.2017.03.027Food and Drug Administration.Dietary supplements.Additional ReadingScientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA).EFSA Journal. 2012;10(7). doi:10.2903/j.efsa.2012.2815Amminger GP, Nelson B, Markulev C, Yuen HP, Schäfer MR, Berger M, Mossaheb N, Schlögelhofer M, Smesny S, Hickie IB, Berger GE, Chen EYH, de Haan L, Nieman DH, Nordentoft M, Riecher-Rössler A, Verma S, Thompson A, Yung AR, McGorry PD.The NEURAPRO biomarker analysis: Long-chain omega-3 fatty acids improve 6-month and 12-month outcomes in youths at ultra-high risk for psychosis.Biol Psychiatry. 2019. doi:10.1016/j.biopsych.2019.08.030Bradberry JC, Hilleman DE.Overview of omega-3 fatty acid therapies.P T. 2013;38(11). PMID: 24391388; PMCID: PMC3875260.Chitre NM, Moniri NH, Murnane KS.Omega-3 fatty acids as druggable therapeutics for neurodegenerative disorders.CNS Neurol Disorders—Drug Targets. 2019. doi:10.2174/1871527318666191114093749Ito MK.A comparative overview of prescription omega-3 fatty acid products.P&T: a peer-reviewed journal for formulary management. 2015;40(12):826-57. PMID: 26681905; PMCID: PMC4671468.Jain AP, Aggarwal KK, Zhang PY.Omega-3 fatty acids and cardiovascular disease.European Review for Medical and Pharmacological Sciences. 2015;19(3):441–445.Patrick RP, Ames BN.Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior.FASEB J. 2015;29(6). doi:10.1096/fj.14-268342
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.
National Institutes of Health.Omega-3 fatty acids.Hilleman DE, Wiggins BS, Bottorff MB.Critical differences between dietary supplement and prescription omega-3 fatty acids: a narrative review.Adv Ther. 2020;37(2):656-670. doi:10.1007/s12325-019-01211-1Khoukaz HB, Fay WP.Fish oil supplements for prevention of cardiovascular disease: the jury is still out.Mo Med.2021 May-Jun;118(3):219–25.Asztalos IB, Gleason JA,Sever W, et al.Effects of eicosapentaenoic acid and docosahexaenoic acid on cardiovascular disease risk factors: a randomized clinical trial.Metabol Clin Exper. 2016:65(11):1636–45. doi:10.1016/j.metabol.2016.07.010GlaxoSmithKline.Lovazo (omega-3-acid ethyl esters) capsules, for oral use.GlaxoSmithKline.Vascepa (icosapent ethyl) capsules, for oral use.Skulas-Ray AC, Wilson PWF, Harris WS, et al.Omega-3 fatty acids for the management of hypertriglyceridemia: a science advisory from the American Heart Association.Circulation. 2019;140(12):e673-e691. doi:10.1161/CIR.0000000000000709MedlinePlus.Omega-3 fatty acids.Jeansen S, Witkamp RF, Garthoff JA, van Helvoort A, Calder PC.Fish oil LC-PUFAs do not affect blood coagulation parameters and bleeding manifestations: analysis of 8 clinical studies with selected patient groups on omega-3-enriched medical nutrition.Clin Nutr.2018 Jun;37(3):948-57. doi:10.1016/j.clnu.2017.03.027Food and Drug Administration.Dietary supplements.
National Institutes of Health.Omega-3 fatty acids.
Hilleman DE, Wiggins BS, Bottorff MB.Critical differences between dietary supplement and prescription omega-3 fatty acids: a narrative review.Adv Ther. 2020;37(2):656-670. doi:10.1007/s12325-019-01211-1
Khoukaz HB, Fay WP.Fish oil supplements for prevention of cardiovascular disease: the jury is still out.Mo Med.2021 May-Jun;118(3):219–25.
Asztalos IB, Gleason JA,Sever W, et al.Effects of eicosapentaenoic acid and docosahexaenoic acid on cardiovascular disease risk factors: a randomized clinical trial.Metabol Clin Exper. 2016:65(11):1636–45. doi:10.1016/j.metabol.2016.07.010
GlaxoSmithKline.Lovazo (omega-3-acid ethyl esters) capsules, for oral use.
GlaxoSmithKline.Vascepa (icosapent ethyl) capsules, for oral use.
Skulas-Ray AC, Wilson PWF, Harris WS, et al.Omega-3 fatty acids for the management of hypertriglyceridemia: a science advisory from the American Heart Association.Circulation. 2019;140(12):e673-e691. doi:10.1161/CIR.0000000000000709
MedlinePlus.Omega-3 fatty acids.
Jeansen S, Witkamp RF, Garthoff JA, van Helvoort A, Calder PC.Fish oil LC-PUFAs do not affect blood coagulation parameters and bleeding manifestations: analysis of 8 clinical studies with selected patient groups on omega-3-enriched medical nutrition.Clin Nutr.2018 Jun;37(3):948-57. doi:10.1016/j.clnu.2017.03.027
Food and Drug Administration.Dietary supplements.
Scientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA).EFSA Journal. 2012;10(7). doi:10.2903/j.efsa.2012.2815Amminger GP, Nelson B, Markulev C, Yuen HP, Schäfer MR, Berger M, Mossaheb N, Schlögelhofer M, Smesny S, Hickie IB, Berger GE, Chen EYH, de Haan L, Nieman DH, Nordentoft M, Riecher-Rössler A, Verma S, Thompson A, Yung AR, McGorry PD.The NEURAPRO biomarker analysis: Long-chain omega-3 fatty acids improve 6-month and 12-month outcomes in youths at ultra-high risk for psychosis.Biol Psychiatry. 2019. doi:10.1016/j.biopsych.2019.08.030Bradberry JC, Hilleman DE.Overview of omega-3 fatty acid therapies.P T. 2013;38(11). PMID: 24391388; PMCID: PMC3875260.Chitre NM, Moniri NH, Murnane KS.Omega-3 fatty acids as druggable therapeutics for neurodegenerative disorders.CNS Neurol Disorders—Drug Targets. 2019. doi:10.2174/1871527318666191114093749Ito MK.A comparative overview of prescription omega-3 fatty acid products.P&T: a peer-reviewed journal for formulary management. 2015;40(12):826-57. PMID: 26681905; PMCID: PMC4671468.Jain AP, Aggarwal KK, Zhang PY.Omega-3 fatty acids and cardiovascular disease.European Review for Medical and Pharmacological Sciences. 2015;19(3):441–445.Patrick RP, Ames BN.Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior.FASEB J. 2015;29(6). doi:10.1096/fj.14-268342
Scientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA).EFSA Journal. 2012;10(7). doi:10.2903/j.efsa.2012.2815
Amminger GP, Nelson B, Markulev C, Yuen HP, Schäfer MR, Berger M, Mossaheb N, Schlögelhofer M, Smesny S, Hickie IB, Berger GE, Chen EYH, de Haan L, Nieman DH, Nordentoft M, Riecher-Rössler A, Verma S, Thompson A, Yung AR, McGorry PD.The NEURAPRO biomarker analysis: Long-chain omega-3 fatty acids improve 6-month and 12-month outcomes in youths at ultra-high risk for psychosis.Biol Psychiatry. 2019. doi:10.1016/j.biopsych.2019.08.030
Bradberry JC, Hilleman DE.Overview of omega-3 fatty acid therapies.P T. 2013;38(11). PMID: 24391388; PMCID: PMC3875260.
Chitre NM, Moniri NH, Murnane KS.Omega-3 fatty acids as druggable therapeutics for neurodegenerative disorders.CNS Neurol Disorders—Drug Targets. 2019. doi:10.2174/1871527318666191114093749
Ito MK.A comparative overview of prescription omega-3 fatty acid products.P&T: a peer-reviewed journal for formulary management. 2015;40(12):826-57. PMID: 26681905; PMCID: PMC4671468.
Jain AP, Aggarwal KK, Zhang PY.Omega-3 fatty acids and cardiovascular disease.European Review for Medical and Pharmacological Sciences. 2015;19(3):441–445.
Patrick RP, Ames BN.Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior.FASEB J. 2015;29(6). doi:10.1096/fj.14-268342
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