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The Daily Insight

Can fish oil upset your stomach

Author

Isabella Browning

Updated on April 20, 2026

Although fish oil is known for its powerful effects on heart health, many people report feeling heartburn after starting to take fish oil supplements. Other acid reflux symptoms — including belching, nausea and stomach discomfort — are common side effects of fish oil due largely to its high fat content.

Can omega-3 cause stomach problems?

Omega-3 fatty acid supplements might cause upset stomach or diarrhea. These side effects are worse at higher doses.

Can fish oil cause gas and bloating?

The most common side effects, which 1% to 10% of people have, include belching, indigestion, nausea, bloating, belly pain, constipation, diarrhea, gas, acid reflux, and vomiting.

What is a common side effect of fish oil?

Fish oil side effects include heartburn, loose stools, and nosebleeds. Taking fish oil supplements with meals or freezing them can reduce these issues. Consuming high amounts of fish oil from DIETARY sources is possibly unsafe.

Do fish oil side effects go away?

Some side effects of omega-3 polyunsaturated fatty acids may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Does fish oil make you smell down there?

Enteric-coated forms of fish oil are designed to dissolve distal to the stomach, reducing the potential for these problems. Taking fish-oil supplements can cause the skin, breath, and urine to have a fishy smell.

Why does fish oil make me poop?

Many of its benefits come from its omega-3 fatty acids. These acids lubricate intestines so food can easily move through the colon.

What medications should not be taken with fish oil?

  • Anticoagulant and antiplatelet drugs, herbs and supplements. These types of drugs, herbs and supplements reduce blood clotting. …
  • Blood pressure drugs, herbs and supplements. Taking fish oil supplements might slightly lower blood pressure. …
  • Contraceptive drugs. …
  • Orlistat (Xenical, Alli). …
  • Vitamin E.

What happens when you take omega-3 every day?

According to the NIH, the FDA have suggested that people should take no more than 3 g per day of DHA and EPA combined. Over long periods, scientists say that omega-3 can reduce immune system function because it lowers the body’s inflammatory responses. High doses of omega-3 may also increase bleeding time.

How much fish oil should I take daily?

A vast amount of research supports supplementing with fish oil. Though there are no conclusive recommendations, 250–500 mg per day of combined EPA and DHA — of which fish oil is an excellent source — is enough for most healthy people. Keep in mind that this will vary depending on your needs.

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Do fish oil tablets make you fart?

It can leave a fishy taste in your mouth or make you a little gassy. The much more serious concern is how krill oil might interact with other drugs you take.

Do omega-3 supplements have side effects?

Side effects from omega-3 fish oil may include: A fishy taste in your mouth. Fishy breath. Stomach upset.

Does omega-3 help bowel movements?

Omega-3 fatty acids are thought to play a role in a large number of bodily functions, including digestion. Some studies have shown that omega-3s can be helpful in managing symptoms of Crohn’s disease and ulcerative colitis, which include constipation.

Does omega3 cause diarrhea?

Diarrhea: Stomach ailments like diarrhea or irregular bowel movements is one of the most common side effects associated with omega -3 fatty acids, and may be especially prevalent while taking high doses. Flax seed oil, fatty fish or other oils have a laxative effect and may increase your bowel movement frequency.

What is the best time to take fish oil?

Although fish oil supplements can be taken at any time of the day, research shows that they are better absorbed during meals. Good sources of fat can increase the bioavailability of omega-3 fatty acids, boosting their efficacy.

How long does it take for fish oil to get in your system?

How long does it take for omega-3’s to work? Levels of omega-3’s build up quickly in the body once you take supplements. But it may take 6 weeks to 6 months to see a significant change in mood, pain, or other symptoms.

Does taking fish oil make you gain weight?

Weight gain As you already know fish oil is rich in fat and is also high in calories, therefore, too much of it can increase your metabolic weight.

Does fish oil make you constipated?

Stomach issues: Some people who take fish oil supplements experience stomach issues such as bloating, gas, diarrhea, or constipation. Bad taste: Fish oil can leave a fishy taste in the mouth, and a person might notice bad breath right after taking the supplement.

Does fish oil help with inflammation?

Because fish oil has anti-inflammatory properties, it may help treat conditions involving chronic inflammation ( 60 ). For example, in stressed and obese individuals, fish oil can reduce the production and gene expression of inflammatory molecules called cytokines ( 61 , 62 ).

Why does it smell when I open my legs?

Sweating. Sweating in the groin area can attract fungus and bacteria that can lead to a bad smell. Showering after exercise or athletic activity can help reduce the bad-smelling effects of smells related to sweating. Putting on clean, dry clothes after a sweat session can also help.

Why does fish oil make me feel weird?

Although fish oil is known for its powerful effects on heart health, many people report feeling heartburn after starting to take fish oil supplements. Other acid reflux symptoms — including belching, nausea and stomach discomfort — are common side effects of fish oil due largely to its high fat content.

Why do I smell down there even after I shower?

Poor hygiene Not bathing or showering regularly can lead to inflammation of the vaginal area, which can cause vaginal odor. Sweating The skin in the groin area is prone to sweating, which can cause vaginal odor.

How much fish oil should a 70 year old woman take?

Older adults and the elderly typically shouldn’t take more than 250 milligrams of EPA and DHA daily. However, when treating high triglycerides, your doctor may recommend up to 15 grams if you have high blood pressure and as much as 10 grams if you have rheumatoid arthritis.

Can I take fish oil at night?

Because most of the benefits of fish oil are associated with long-term use, you can take it at any time of day. That said, splitting your supplement into two smaller doses in the morning and at night can reduce acid reflux.

Does fish oil raise cholesterol?

Although there are popular myths that taking fish oil lowers your cholesterol, it does not. It will lower your triglycerides, may modestly raise your HDL (which is a benefit), but can actually raise your LDL (bad) cholesterol, which is not a benefit.

When should you not take omega-3?

Most People Don’t Need to Take Omega-3 Supplements. Researchers in a new study say people who have had a heart attack can benefit from fish oil and other supplements. But most people don’t need them. Omega-3s are a group of polyunsaturated fatty acids that perform key functions in the human body.

Can I take ibuprofen with fish oil?

Interactions between your drugs Talk to your doctor before using omega-3 polyunsaturated fatty acids together with ibuprofen. Fish oil and other products containing omega-3 fatty acids may rarely increase the risk of bleeding when combined with other medications that can also cause bleeding such as ibuprofen.

What are the side effects of omega-3 6 9?

  • Bleeding gums.
  • coughing up blood.
  • difficulty with breathing or swallowing.
  • fast or irregular heartbeat.
  • hives, itching, or skin rash.
  • increased menstrual flow or vaginal bleeding.
  • nosebleeds.
  • paralysis.

Does fish oil supplements cause headaches?

Share on Pinterest Side effects of taking omega-3 supplements include nausea and headaches. According to the NCCIH , the side effects from omega-3 supplements are usually mild and might include: bad breath.

Is fish oil really good for your heart?

Numerous studies have found that they can be good for a person’s heart and can help lower cholesterol. Due to its positive health effects, fish oil supplements high in omega-3 fatty acids have become one of the most common supplement types on the market.

Can fish oil cause sweating?

“Vitamin burps” or don’t just happen with fish oil, but this can be a sign that whatever you’re taking is breaking open before it hits your digestive tract. Most of this is anecdotal, but many people report belching and “fishy” breath and even unpleasant-smelling sweat when they take fish oil.