Have you considered taking omega-3 supplements but are still a bit hesitant because of stories about side effects? What’s really true, and what’s exaggerated? In this blog, we’ll give you an honest look at what omega-3 side effects exist, how often they occur, and—more importantly—how you can easily prevent them. You’ll also learn what happens if you take too much omega-3 and whether it matters which form you choose.
What are the side effects of omega-3?
Let’s start with the facts. Yes, omega-3 supplements can have side effects. But before you panic: real side effects are rare and usually mild. The problem? Much of what people mistake for “side effects” are actually signs of poor quality.
Those Annoying Fishmongers
Maybe you've experienced this: you take an omega-3 capsule, and hours later you can still taste fish. Many people think this is normal, but nothing could be further from the truth. That unpleasant fishy taste means the omega-3 fatty acids have been damaged. They've oxidized (gone rancid), and that isn't necessarily good for your body.
A good omega-3 oil never leaves a fishy aftertaste. In fact, you can even take high-quality fish oil straight from the spoon without any unpleasant aftertaste. This is sometimes the difference between a (cheaper) fish oil of unknown origin and fish oil made from fresh, wild cod from northern waters.
Stomach and intestinal problems
Some people experience stomach and intestinal discomfort from omega-3 supplements. You take a capsule and feel bloated, nauseous, or have diarrhea. But once again, quality plays a role here. Rancid, damaged oils irritate your stomach much more than fresh, pure omega-3.
This happens much more often with cheap supplements than with high-quality omega-3 supplements. And when it does happen, it usually goes away within a few days. Your stomach just needs some time to get used to the new supplement.
Allergic reactions
Are you allergic to fish or shellfish? If so, you might also have a reaction to fish oil. But this isn’t necessarily the case, because reactions are often caused by protein. Liquid fish oil contains no protein, only fat. Capsules, on the other hand, do contain fish gelatin, which is a protein.
Fortunately, you don't have to miss out on the benefits of omega-3. There are great plant-based alternatives, such as algae oil.
Algae oil contains the same beneficial EPA and DHA fatty acids, but they’re produced by algae instead of fish. Do you have a fish allergy? Are you vegan? Or do you simply prefer a plant-based diet? If so, algae oil is the perfect choice.
Does omega-3 affect your blood pressure and blood clotting?
Omega-3 can slightly thin your blood and lower your blood pressure a bit. For most people, this isn’t a problem. In fact, EPA and DHA contribute to normal heart function* and can help maintain normal blood pressure*. If you naturally have low blood pressure or are already taking blood thinners, it’s a good idea to check with your doctor first.
Does omega-3 affect your blood sugar?
Have you read somewhere that omega-3 can affect your blood sugar? This happens when extremely high doses are taken—much more than what people normally consume. At normal doses (such as those found in supplements), your blood sugar remains completely unaffected. Are you diabetic and still concerned? Then just keep an eye on your blood sugar for the first few weeks. You’ll see that nothing changes.
Side Effects of Too Much Omega-3: How Much Is Too Much?
Is it actually possible to consume too much omega-3? In theory, yes, but we’re talking about substantial amounts. The European Food Safety Authority (EFSA) has investigated this. Up to 5 grams of EPA and DHA per day from supplements is not a cause for concern for adults. For example, EFSA found that at that amount, there was no increased risk of bleeding or impaired blood sugar levels, as long as the oil is fresh.
By way of comparison: the Health Council of the Netherlands recommends about 200 mg of EPA and DHA per day for adults. That’s roughly what you get if you eat fatty fish once a week. Even the highest-dose oils from Arctic Blue contain about 1.25 grams per serving. If you stick to the dosage on the package, you’ll be well below that 5-gram mark.
Are you taking much more than you need? If so, you’re more likely to experience stomach or intestinal discomfort. In that case, taking less often helps. Also, be careful if you’re combining multiple products, such as fish oil and a multivitamin containing omega-3. Be sure to add up the EPA and DHA.
When should you consult your doctor?
Are you taking blood thinners or other medications? Or do you have cardiovascular disease? If so, consult your doctor or pharmacist first. This is because people with cardiovascular disease have reported an irregular or rapid heartbeat when taking omega-3. Do your symptoms persist, even when you take omega-3 with a meal? If so, it’s a good idea to see your doctor.
Side Effects by Omega-3 Supplement: Fish Oil, Algae Oil, and Omega-3-6-9
Does it matter which supplement you choose? The possible side effects are very similar, but there are a few differences.
Fish oil: liquid or capsules
When it comes to fish oil, burping and a fishy aftertaste are the most common complaints. This applies to both liquid fish oil and omega-3 capsules. The idea that you don’t taste fish when taking a capsule is only partly true. You don’t taste anything while swallowing, but the capsule dissolves in your stomach. If the oil isn’t fresh, you’ll still burp it up. You can taste liquid fish oil right away. That way, you know immediately if the oil is fresh.
Would you like to learn more about fish oil suppliers, capsules, and other important considerations? Then be sure to check out our page on fish oil side effects.
Algae Oil
Algae oil does not contain fish, so you won’t have to deal with fishmongers. The capsules from Arctic Blue also have a plant-based coating. But be aware: the omega-3 fatty acids in algae oil are just as susceptible to oxidation as those in fish oil. Old or stale algae oil can therefore also start to smell bad. In addition, algae oil, like any oil, can cause stomach or intestinal discomfort in some people—especially on an empty stomach. So just take it with a meal.
Omega-3, -6, and -9 Supplements
You’ll also find supplements that combine omega-3, -6, and -9. The side effects are similar: mainly mild stomach and intestinal discomfort. Be sure to check the label carefully. The omega-3 in these products is sometimes (partly) ALA from plant-based oils, such as flaxseed oil. This is a different type of omega-3 than EPA and DHA. The label will tell you how much EPA and DHA you’re actually getting per daily dose.
Prevent Omega-3 Side Effects with These 5 Tips
Now that you know what’s really going on, we can get started with some practical tips. You can prevent virtually all omega-3 side effects by making the right choices.
- Choose quality with certifications: look for the MSC label on fish oil or the Vegan label on algae oil. These certifications prove that the fish meets the MSC standard for environmental sustainability, or that the algae oil is made from 100% plant-based ingredients.
- Pay attention to the source: fish oil from fresh, wild cod caught in cold, clean waters is very different from oil of unknown origin that may have traveled around the world for months. Arctic Blue , for example, uses only cod fillet trimmings—this ensures freshness without waste.
- Always take it with food: during or shortly after a meal, possibly even with a little fat, such as nuts or avocado. This prevents stomach upset and improves absorption. Do not take it on an empty stomach if you are sensitive to it.
- Choose the form that's right for you: Don't like taking fish oil? You can also opt for convenient fish oil capsules, algae oil, or even tasty gummies.
- Stick to the recommended dosage: more isn’t always better. Follow the dosage instructions on the packaging and add up the EPA and DHA from different products. That way, you’ll stay well below the 5 grams per day that the EFSA considers safe for adults.
The benefits outweigh the risks
Why do so many people choose to take omega-3 supplements? Simple: the benefits are well worth it. EPA and DHA contribute to normal heart function*. DHA is also good for brain function* and helps maintain normal vision*. EPA and DHA may also help maintain normal blood pressure*. These benefits have been scientifically proven and recognized by the European Food Safety Authority.
Finally: Do you experience side effects from omega-3?
The truth about omega-3 side effects is that they do exist, but they’re much rarer than you might think. Millions of people worldwide take omega-3 every day without any problems. With the right approach, you can be one of them.
The most important thing? Choose a supplement with the MSC seal of approval for fish oil or the Vegan seal of approval for algae oil, and stick to the recommended dosage. Fresh, pure omega-3 doesn’t have any unpleasant aftertaste. So don’t let fear of side effects keep you from giving your heart, brain, and eyes the nutrition they need.
*Health claims approved by the EFSA. The beneficial effect on heart function and brain function is achieved with a daily intake of 250 mg of EPA and DHA. For vision, the beneficial effect is achieved with 250 mg of DHA. For blood pressure, the beneficial effect is achieved with 3 grams of EPA and DHA per day (it is not safe to take more than 5 grams of EPA and DHA per day).
