Can Fish Oil Cause Constipation?

Revealed - the truth behind how fish oil may support your gut health and bowel movement.

Medically reviewed by Silky Mahajan, CSN, CDE Silky Mahajan Silky MahajanCSN, CDE facebook_iconinsta_icon
Written by , B.Desgn, ISSA Certified Specialist In Fitness & Nutrition Tanya Choudhary B.Desgn, ISSA Certified Specialist In Fitness & Nutrition twitter_icon Experience: 2 years
Edited by , BSc, Professional Certificate in Food, Nutrition and Health Ravi Teja Tadimalla BSc, Professional Certificate in Food, Nutrition and Health linkedin_icon Experience: 8 years
Fact-checked by , BPharm, Certified Health & Wellness Coach Moksha Gandhi BPharm, Certified Health & Wellness Coach linkedin_icon Experience: 2 years

Fish oil supplements rich in omega-3 fatty acids are commonly prescribed for their many key health benefits. However, its effects on your digestive health and constipation issues remain a mystery to many. Do fish oil and constipation go hand in hand or can fish oil supplements help alleviate constipation? The internet is divided in its opinions. To help you get the right understanding, we have done the research and broken apart the facts from myths for you. Read on to find out!

protip_icon Know Your Ingredient: Fish Oil

What Is It?
Oil or fat extracted from the tissues of fish for Omega-3 fatty acids.

What Are Its Benefits?
It relieves constipation, boosts memory, improves eye health, supports bone and joint health, and may reduce the risk of prostate cancer.

Who Can Use It?
Generally safe for anyone without a serious medical history.

How Often?
Up to 3 grams is safe for daily consumption.

Excess or bad-quality fish oil can lead to digestive issues, heartburn, and nosebleeds.

What Is Fish Oil?

Fish oil supplements kept in a fish-shaped bowl
Image: Shutterstock

Extracted from the fatty tissues of oily fish, fish oil contains various beneficial chemicals like DHA, EPA and most importantly, omega 3 fatty acids. The fish do not produce omega 3 fatty acids on their own. They consume a lot of algae or smaller fishes that contain this beneficial fatty acid. So, fishes higher up in the food chain accumulate larger amounts of omega 3 fatty acids, which is why large predatory fishes like swordfish, tilefish and shark are tapped as fish oil sources. However, this biomagnification is also responsible for the pooling of toxic materials collected from various fishes.

Fish Oil And Constipation – The Myth

Woman with constipation and bowel issues
Image: Shutterstock

There are several instances of people asking in online forums whether fish oil causes constipation. They claim that after taking fish oil supplements they have had difficulty in passing stool. This claim is also ratified by several articles found online. However, it is a myth because scientific studies have shown that fish oil relieves constipation. The only possible explanation behind these claims is that they were ingesting some other supplements or foods that could be causing constipation.

protip_icon Trivia
Fish oil extracted from fish from the deep cold ocean water (North Atlantic waters near Norway) is considered the highest quality.

How It Helps

Fish oil capsules are great source of omega-3 fats
Image: Shutterstock

Does fish oil help with constipation? Fish oil contains omega-3 fatty acids known to ease irritable bowel syndrome, a condition that may cause constipation as a symptom (1). Fish oil stimulates intestinal alkaline phosphatase production, which is important for good gut bacterial communication and helps reduce intestinal inflammations. So moderate fish oil, a high fiber diet with proper water consumption for nutrition, and exercise can help to reduce constipation.

Fish oil may be suggested to pregnant women and anyone, in general, suffering from constipation. Some believe the oil helps in lubrication of the colon and ease the passage of food, though more research is warranted in this regard. The omega 3 fatty acids also help in reducing the associated inflammation. Thus, all problems related to constipation are also addressed if you take fish oil supplements.

Other Benefits

Woman taking fish oil supplement for its health benefits
Image: Shutterstock

Apart from relief from constipation, fish oil also treats several other symptoms. Other benefits include:

  1. Fish oil may reduce the risk of developing prostate cancer (2). A low-fat diet, which is rich in omega 3 fatty acids, is considered to be beneficial for those who are at a higher risk of developing this type of cancer.
  2. Fish oil helps pregnant women to deal with postpartum depression (3). The oil contains DHA and doctors often prescribe DHA-rich foodsi  Known as docosahexaenoic acid, it is found in foods, such as fish and milk. It helps regulate brain function in the body. to such women.
  3. The omega 3 fatty acids present in fish oil have shown to improve memory, especially in young adults (4).
  4. Regular intake of fish oil is linked to lower risk of developing Alzheimer’s disease (5). However, there is some confusion about this benefit because a recent study concluded that fish oil acts only as well as a placebo.
  5. Developing fetuses are benefitted from omega 3 fatty acids (6). When pregnant women take fish oil, it leads to better motor and cognitive development in their babies.
  6. Age related vision loss is often reversed or inhibited by fish oil consumption.
  7. EPA and DHA found in fish oil boost heart health, reduces blood pressure, and improves blood cholesterol and triglyceridei  A type of fat found in the bloodstream. Following a meal, the body converts unwanted calories into triglycerides. levels.
  8. It has anti-inflammatory properties and is beneficial for Rheumatoid arthritis and multiple sclerosisi  A disease that affects the brain, spinal cord, and optic nerves of the body as a result of an autoimmune reaction. .
  9. It also helps to maintain healthy skin.
  10. It supports bone and joint health.
  11. Gavyn Berntsen, a blogger, had undergone six knee operations to treat joint pain. One of the surprising steps he follows is consuming fish oil. He writes, “Fish oil has immunosuppressive properties, so it can benefit people with rheumatoid arthritis. It has also been shown to alleviate work-related joint pain (i)…”
protip_icon Quick Tip
Fish oil supplements can help reduce the severity of some skin disorders like allergies, photoagingi  Premature aging caused by prolonged exposure to UV radiation. It leads to the formation of dark spots, fine lines, and wrinkles. , and dermatitis (9).


Woman facing the risks of excess supplement consumption
Image: Shutterstock

Although the benefits are aplenty, fish oil is not devoid of side effects (7). Consuming excessive or poor-quality fish oil can cause diarrhea, and vitamin A toxicity (as most fish oil contains high vitamin A). Also, fish oil is not advised for people with low blood pressure or people on blood-thinning medications. Also, with increasing pollution in the oceans, many small fishes and algae ingest toxic materials that are not only harmful to them and the rest of the food chain, but are also non-biodegradable. This means that when such organisms are eaten by predators, they are passed on to the latter.

By consuming a number of toxin-infested fishes, these predators accumulate lots of toxins. As a result, these toxins are passed into fish oil and consequently to those who take this supplement.

Apart from that, consuming fish oil may also cause gas and bloating. Let’s learn more about it.

Does Fish Oil Cause Gas?

Consuming fish oil supplements may sometimes cause gastrointestinal discomfort due to the high levels of omega-3 fatty acids, specifically EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), found in fish oil. These may irritate the gastrointestinal tract in some individuals and cause gastrointestinal discomfort, gas, or bloating (8).

This may be due to the dosage, the form of fish oil (liquid or capsules), or an individual’s sensitivity. Start with a lower dose and gradually increase it to help minimize these side effects. You can take fish oil with your meals also to reduce the likelihood of digestive discomfort.

If you experience persistent or severe gas, bloating, or other digestive issues when taking fish oil, consult a doctor. They may recommend alternative sources of omega-3 fatty acids or adjust your dosage to minimize these side effects.

Infographic: How Does Fish Oil Relieve Constipation?

Fish oil has a range of potential health benefits. It is rich in omega-3 fatty acids, which are anti-inflammatory and can improve gut health as well as promote better bowel movement. It is also essential for its antimicrobial properties. Check the infographic below to learn the many benefits of fish oil!

does fish oil aggravate or relieve constipation (infographic)

Illustration: StyleCraze Design Team

Fish oil contains higher amounts of beneficial omega-3 fatty acids that help your health. You can pair that up with some probiotics and prebiotics, which keeps your liver healthy and promotes digestion and gut health (9). Intake of fish oil supplements, rich in these fatty acids, may help reduce inflammation that is often associated with constipation. However, overconsumption of this healthy oil does more harm than good. It may cause several side effects due to the potential presence of toxins. Hence, consume fish oil supplements only in moderation. Consult your doctor in case of any emergencies.

Frequently Asked Questions

Who should not take fish oil?

People who are allergic to seafood should avoid fish oil.

Is 1000 mg of fish oil too much?

No. 1000 mg of fish oil supplies around 300 mg of combined EPA and DHA (250-500 mg of EPA and DHA is allowed) (10).

What happens when you take omega-3 every day?

Omega-3 fats may help prevent heart disease and improve brain function when consumed every day.

Is it better to take fish oil in the morning or at night?

You can take fish oil any time in the day.

How soon does fish oil start working?

Most people experience the benefits of fish oil within two to three months.

What is better than fish oil for inflammation?

Krill oil is better than fish oil for inflammation.

Key Takeaways

  • Fish oil is extracted from fatty tissues of oily fish and is rich in omega fats.
  • Fish oil alone doesn’t cause constipation problems, but the foods that are taken along with fish oil may cause it.
  • The intake of a diet rich in fiber along with regular exercise and proper hydration may help prevent constipation.
  • However, consuming excess or poor-quality fish oil may cause side effects, such as diarrhea.
fish oil and constipation

Image: Stable Diffusion/StyleCraze Design Team

Explore the world of fish oil pills, packed with multiple health benefits. However, there are precautions you should know. Uncover the potential side effects and ways to avoid them in this informative video. Watch it now!

Personal Experience: Source


Articles on StyleCraze are backed by verified information from peer-reviewed and academic research papers, reputed organizations, research institutions, and medical associations to ensure accuracy and relevance. Read our editorial policy to learn more.

  1. Omega-3 Fatty Acids
  2. Fish-Derived Omega-3 Fatty Acids and Prostate Cancer: A Systematic Review
  3. Fish-Oil Supplementation and Maternal Mental Health: A Triple-Blind, Randomized Controlled Trial
  4. Effects of Omega-3 Fatty Acids on Cognition and Behaviour in Childhood
  5. Omega-3 Fatty Acids: Potential Role in The Management of Early Alzheimer’s Disease
  6. Omega-3 Fatty Acids and Pregnancy
  7. Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease
  8. Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA)
  9. Dietary Intakes of EPA and DHA Omega-3 Fatty Acids among US Childbearing-Age and Pregnant Women: An Analysis of NHANES 2001–2014
  10. Cosmetic and Therapeutic Applications of Fish Oil’s Fatty Acids on the Skin
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Silky Mahajan

Silky MahajanMSc, CSN, CDE

Silky has been practicing nutrition for more than 14 years and is an active member of the Indian Dietetics Association (IDA). She has a masters degree in nutrition and dietetics and is a Certified Sports Nutritionist and Certified Diabetes Educator.   Under sports nutrition, she widely covers most nutrition aspects, such as carbohydrate loading, hydration strategy, energy, endurance, muscle building, full bio

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