Side Effects of Fish Oil

fish oil

Fish oil is well known for its wealth of health-promoting residential or commercial properties. Rich in heart-healthy omega-3 fats, fish oil has been shown to decrease blood triglycerides, eliminate swelling and even ease symptoms of conditions such as rheumatoid arthritis.

However, more fish oil is not always much better, and taking too high a dosage may really do more harm than great when it concerns your health.

Here are 8 prospective adverse effects that can occur when you take in excessive fish oil or omega-3 fats.

High Blood Sugar

Some research reveals that supplementing with high amounts of omega-3 fatty acids might increase blood sugar levels in individuals with diabetes.

One small research study, for example, found that taking 8 grams of omega-3 fats each day resulted in a 22% increase in blood glucose levels in people with type 2 diabetes over an eight-week duration.

This is because big dosages of omega-3s can stimulate the production of glucose, which can add to high levels of long-term blood sugar level levels.

However, other research has shown up conflicting outcomes, suggesting that just really high doses impact blood sugar.

In truth, another analysis of 20 studies found that day-to-day dosages of up to 3.9 grams of EPA and 3.7 grams of DHA — the 2 main types of omega-3 fats — had no effect on blood sugar levels for individuals with type 2 diabetes.


Bleeding gums and nosebleeds are 2 of the trademark side effects of excess fish oil usage.

One study in 56 individuals found that supplementing with 640 mg of fish oil per day over a four-week duration reduced blood clot in healthy grownups.

Furthermore, another little study showed that taking fish oil might be linked to a greater risk of nosebleeds, reporting that 72% of adolescents taking 1 — 5 grams of fish oil daily skilled nosebleeds as a side impact.

For this factor, it’s often recommended to stop taking fish oil previous to surgery and to talk with your medical professional before taking supplements if you’re on blood thinners like Warfarin.

Low Blood Pressure

Fish oil’s capability to lower blood pressure is well documented.

One research study of 90 individuals on dialysis discovered that taking 3 grams of omega-3 fats each day substantially reduced both systolic and diastolic blood pressure compared to a placebo.

Likewise, an analysis of 31 studies concluded that taking fish oil can successfully decrease blood pressure, specifically for those with high blood pressure or high cholesterol levels.

While these results can certainly be beneficial for those with hypertension, it can cause severe problems for those who have low high blood pressure.

Fish oil may also communicate with blood pressure-lowering medications, so it’s crucial to go over supplements with your doctor if you’re receiving treatment for hypertension.


Diarrhea is one of the most typical negative effects connected with taking fish oil, and might be particularly prevalent while taking high doses.

In fact, one evaluation reported that diarrhea is among the most common unfavorable effects of fish oil, along with other digestion symptoms such as flatulence.

In addition to fish oil, other kinds of omega-3 supplements may also cause diarrhea.

Flaxseed oil, for instance, is a popular vegetarian alternative to fish oil, however has actually been shown to have a laxative impact and may increase bowel motion frequency.

If you experience diarrhea after taking omega-3 fatty acids, make certain you’re taking your supplements with meals and consider decreasing your dose to see if signs persist.


Although fish oil is understood for its effective results on heart health, lots of people report feeling heartburn after beginning to take fish oil supplements.

Other acid reflux symptoms — consisting of belching, queasiness and stomach pain — are typical adverse effects of fish oil due largely to its high fat material. Fat has been shown to activate indigestion in a number of studies.

Sticking to a moderate dosage and taking supplements with meals can frequently successfully lower acid reflux and relieve signs.

In addition, splitting your dose into a few smaller sized parts throughout the day might assist get rid of indigestion.


Hemorrhagic stroke is a condition identified by bleeding in the brain, usually triggered by the rupture of weakened blood vessels.

Some animal research studies have found that a high consumption of omega-3 fatty acids might decrease the blood’s ability to clot and increase the danger of hemorrhagic stroke.

These findings are also consistent with other research study showing that fish oil might hinder embolism formation.

However, other studies have actually turned up blended results, reporting that there is no association between fish and fish oil consumption and hemorrhagic stroke danger.

Additional human studies need to be performed to identify how omega-3 fatty acids may affect the risk of hemorrhagic stroke.

Vitamin A Toxicity

Certain types of omega-3 fatty acid supplements are high in vitamin A, which can be harmful if consumed in large amounts.

For instance, just one tablespoon (14 grams) of cod liver oil can satisfy up to 270% of your daily vitamin A requires in one serving.

Vitamin A toxicity can trigger negative effects such as dizziness, nausea, joint discomfort and skin irritation.

Long term, it might likewise result in liver damage and even liver failure in serious cases.

For this factor, it’s finest to pay very close attention to the vitamin A material of your omega-3 supplement and keep your dosage moderate.


Some studies have actually discovered that taking moderate dosages of fish oil might improve sleep quality.

One research study of 395 children, for example, revealed that taking 600 mg of omega-3 fatty acids daily for 16 weeks helped enhance sleep quality.

Sometimes, though, taking excessive fish oil may actually disrupt sleep and add to insomnia.

In one case study, it was reported that taking a high dose of fish oil worsened symptoms of sleeping disorders and anxiety for a patient with a history of depression.

However, current research is restricted to case research studies and anecdotal reports.

More research is needed to comprehend how big doses might impact sleep quality in the basic population.

How Much Is Too Much?

Although suggestions can differ commonly, most health companies suggest an intake of a minimum of 250 — 500 milligrams of combined EPA and DHA, the two important types of omega-3 fatty acids, daily.

Nevertheless, a higher quantity is often advised for people with specific health conditions, such as heart disease or high triglyceride levels.

For reference, a normal 1,000-mg fish oil softgel usually consists of about 250 mg of combined EPA and DHA, while one teaspoon (5 ml) of liquid fish oil crams in around 1,300 mg.

According to the European Food Safety Authority, omega-3 fatty acid supplements can be safely consumed at dosages up to 5,000 mg daily.

As a basic general rule, if you experience any negative symptoms, simply decrease your consumption or consider meeting your omega-3 fatty acid needs through food sources rather.

Ali Gadimov
Diet Expert