What Happens If You Take Too Many Omegas?

December 7, 2025 •

3 min read

According to the National Institutes of Health (NIH), the U.S. Food and Drug Administration (FDA) has suggested that people should take no more than 5 g per day of combined EPA and DHA from supplements. Exceeding this limit, or otherwise overconsuming omega fatty acids, can lead to a variety of adverse effects on your health.

Quick Summary

Exceeding the recommended dosage of omega fatty acids, particularly from supplements, can trigger several adverse health effects, including a higher risk of bleeding, digestive issues, low blood pressure, and potential interactions with certain medications.

Key Points

Excessive Intake Increases Bleeding Risk: High doses of omega-3s, particularly above 3 grams daily, can act as a blood thinner and increase the risk of bleeding and bruising.
Gastrointestinal Distress is Common: Overconsumption can lead to digestive issues like fishy burps, nausea, heartburn, diarrhea, and abdominal discomfort.
Risk of Hypotension: For those already on blood pressure medication, too much omega-3 can cause blood pressure to drop to dangerously low levels.
Cod Liver Oil Can Cause Vitamin A Toxicity: Some omega-rich supplements contain high levels of Vitamin A, and excessive intake can lead to toxicity and potential liver damage.
Immune System Can Be Suppressed: While beneficial in moderation, very high doses of omega-3s can suppress the immune system, making the body more vulnerable to infections.
Balance Omega-3 with Other Fats: An imbalanced ratio of omega-6 to omega-3 can promote inflammation, while an excessive omega-9 intake with a poor diet can contribute to weight gain.
Always Consult a Doctor: Before starting any supplement, and especially with high doses or pre-existing conditions, consult a healthcare professional to ensure safety.

The Dangers of Excessive Omega-3 Intake

While omega-3 fatty acids are celebrated for their health benefits, including supporting heart and brain health, more is not always better. High-dose supplementation can introduce significant risks that undermine the very health you are trying to support. Understanding these risks is crucial for anyone considering a high intake of fish or other omega-rich oils.

Increased Bleeding Risk

One of the most well-documented side effects of excessive omega-3 intake is its impact on blood clotting. Omega-3s possess an antiplatelet effect, which means they can thin the blood and inhibit the formation of blood clots. While this is beneficial for some aspects of cardiovascular health, an overly high dose can elevate your risk of bleeding and bruising, especially for those on anticoagulant medication. This risk is heightened before surgery, where a healthcare professional may advise stopping supplementation weeks in advance.

Gastrointestinal Distress

Many individuals report gastrointestinal problems as one of the most common side effects when taking high doses of fish oil supplements. These issues can manifest in various ways:

Fishy Burps and Bad Breath: An unpleasant fishy aftertaste is a frequent complaint, sometimes accompanied by bad-smelling sweat.
Nausea and Heartburn: The high fat content of fish oil can cause stomach upset, nausea, and acid reflux symptoms.
Diarrhea and Constipation: Some people experience changes in bowel movements, ranging from loose stools to constipation.
Abdominal Pain: Discomfort and bloating in the stomach area can occur due to digestive irritation.

Potential Impact on Blood Pressure

Omega-3s are known to help lower blood pressure, which is a desirable effect for many. However, in excess, this can become a serious problem. For individuals already taking medication for hypertension, a high dose of omega-3s could cause blood pressure to drop dangerously low (hypotension), leading to symptoms such as dizziness, lightheadedness, and fainting.

Compromised Immune Function

In very large quantities, the anti-inflammatory effects of omega-3s can become detrimental by suppressing the immune system. While reducing chronic inflammation is beneficial, an excessive reduction can make the body less effective at fighting off infections, leaving you more vulnerable to illness.

The Role of Omega-6 and Omega-9

While the main concerns are typically associated with omega-3s from fish oil, it's important to understand the broader omega landscape. The key is balance. High intake of omega-6, often found in vegetable oils, can promote inflammation when the omega-6 to omega-3 ratio is imbalanced. Similarly, while omega-9 from olive oil has benefits, consuming an excess, especially with a high-fat, high-cholesterol diet, can increase the risk of obesity and cardiovascular disease. It is the disproportionate intake, not just excess volume, that can be problematic across the omega family.

Omega Intake Comparison


Omega Fatty Acid	Source (High Intake)	Potential Excess Side Effects
Omega-3	Fish oil supplements, oily fish	Increased bleeding risk, GI upset, low blood pressure
Omega-6	Soybean oil, corn oil, certain supplements	Increased inflammation, water retention, higher blood pressure
Omega-9	Olive oil, nuts, avocados	Increased risk of obesity and cardiovascular disease (with imbalanced diet)

Other Significant Risks

Vitamin A Toxicity: Some omega supplements, particularly cod liver oil, are rich in Vitamin A. Consuming too much can lead to Vitamin A toxicity, causing symptoms like nausea, dizziness, and in severe, long-term cases, liver damage.
Insomnia: While moderate doses of fish oil can improve sleep, excessive amounts may disrupt sleep patterns and contribute to insomnia in some individuals.
Increased LDL Cholesterol: In some instances, very high doses of omega-3 can lead to an increase in LDL (“bad”) cholesterol levels.

Conclusion

While omega fatty acids are vital for health, an overzealous approach to supplementation can lead to a number of adverse effects. Exceeding recommended dosages, especially above 5 grams per day for EPA and DHA, can increase the risk of bleeding, cause severe gastrointestinal issues, and lead to potentially dangerous drops in blood pressure. It is always best to prioritize getting your omega fatty acids from whole food sources like oily fish, which provide a broader range of nutrients and reduce the risk of mega-dosing. For those who do require supplements, starting with a low dose and consulting a healthcare professional is the safest path forward. If you experience persistent side effects, lowering the dose or stopping the supplement may be necessary to resolve the issues.

For more information on recommended dosages, refer to the National Institutes of Health Office of Dietary Supplements guidelines.

Frequently Asked Questions

Common side effects include a fishy aftertaste or burps, bad breath, gastrointestinal problems like nausea, heartburn, and diarrhea, as well as an increased risk of bruising or bleeding.

Yes, high doses (typically above 3-5 grams daily) can increase the risk of bleeding due to its blood-thinning, antiplatelet effects. This is especially risky for people on anticoagulant medications.

Yes, since cod liver oil is high in Vitamin A, consuming excessive amounts can lead to Vitamin A toxicity, causing symptoms like dizziness, nausea, and potentially liver damage over time.

While omega-3s can help lower blood pressure, excessive intake, particularly for those on blood pressure medication, can cause it to drop too low, resulting in hypotension, dizziness, or lightheadedness.

Pay attention to symptoms like persistent gastrointestinal issues (nausea, diarrhea), increased bruising or bleeding, lightheadedness, or a fishy taste that doesn't go away. If these occur, consider lowering your dosage or speaking with a doctor.

An imbalanced ratio of omega-6 to omega-3 can promote inflammation. While omega-9 is beneficial, excessive intake combined with an unhealthy diet can increase risks for conditions like obesity.

If you experience minor side effects, try taking your supplements with food or reducing the dosage. For severe symptoms like allergic reactions or unusual bleeding, stop taking the supplement and seek immediate medical attention.