Fish Oil Dosage: How Much Should You Take Per Day?

Although there’s no universally prescribed daily amount for fish oil, taking it can help you meet the suggested daily intake of omega-3 fatty acids.

Many individuals include fish oil supplements in their everyday routines.

Beyond supporting brain, eye and heart health, fish oil may also help reduce inflammation in the body.

Numerous healthcare professionals endorse its use. Still, you might be unsure about the appropriate dosage for your needs.

This article explains how much fish oil you might take for optimal wellbeing.

Why Use It?

Fish oil offers several potential health advantages.

It delivers omega-3 fatty acids, which are protective for the heart. These omega-3s must be obtained from food, since the body cannot manufacture them.

Some fish oil preparations also contain vitamin A, an important antioxidant, and vitamin D, crucial for bone health and immune function.

The primary omega-3s in fish oil are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which play roles in brain development and performance ( , ).

Fish oil is a rich source of these fatty acids.

If you don’t consume oily fish on a regular basis, getting enough EPA and DHA can be challenging — most other dietary omega-3s are alpha-linolenic acid (ALA). ALA does not seem to provide the same benefits as EPA and DHA.

Additionally, the typical Western diet tends to be low in omega-3s relative to omega-6s. Thus, a fish oil supplement can be a helpful addition.

Summary

Fish oil provides the omega-3s EPA and DHA, which are important for brain development and function. If you rarely eat fatty fish, consider supplementation.

Suggested Amounts

There isn’t a fixed guideline for how much fish oil one should take.

However, guidance exists for overall omega-3 consumption and specific EPA and DHA amounts.

The reference daily intake (RDI) for combined EPA and DHA is 250–500 mg.

When selecting fish oil products, check the label to see the EPA and DHA content. Typically, 1,000 mg of fish oil contains roughly 300 mg of combined EPA and DHA.

For Healthy Adults

The RDI for total omega-3 is 1,100 mg for women and 1,600 mg for men.

Many people obtain some omega-3s from foods like flaxseed, soybean oil and walnuts — but those sources primarily supply ALA.

Although the body can convert ALA to EPA and DHA, it usually does not produce sufficient levels. Unless you eat about two servings (8 ounces or 224 grams) of oily fish weekly, you may be low in EPA and DHA.

Generally, up to 3,000 mg of fish oil per day is regarded as safe for adults.

During Pregnancy

EPA and DHA are important for normal fetal growth. DHA, especially, accumulates in the fetal brain in the final trimester.

Many expectant mothers fail to reach the recommended levels for these fatty acids.

Supplementing with EPA and DHA during pregnancy can also offer benefits to the child during infancy and childhood, such as enhanced problem-solving abilities and lowered risk of asthma and food allergies.

The WHO advises 300 mg of combined EPA and DHA daily during pregnancy, with 200 mg of that as DHA.

Because most fish oil formulas contain more EPA than DHA, seek products with a higher DHA proportion when pregnant.

Exercise caution with cod liver oil while pregnant, as it can contain high amounts of vitamin A. Excessive vitamin A intake may negatively affect fetal development.

For instance, a single teaspoon (4 ml) of cod liver oil supplies 2,501 IU of vitamin A — roughly 97% of the pregnancy RDI (, 21, ).

Infants and Children

The adequate intake of omega-3 for infants up to 1 year is 500 mg, increasing gradually to standard adult levels by age 14.

Recommendations for EPA and DHA differ by age as well.

For example, about 100 mg of combined EPA and DHA is suggested for a 4-year-old, while an 8-year-old typically needs around 200 mg.

Children’s fish liver oil products will naturally contain some vitamins A and D — since these vitamins accumulate in fish liver — while other fish oil supplements may include added vitamins D, A and E. Vitamin E helps protect the oil from oxidation and can extend shelf life.

When choosing a fish oil supplement for babies or kids, opt for products tailored to the specific life stage to ensure appropriate nutrient levels.

Summary

While there are general recommendations for EPA and DHA for healthy adults, pregnant women, infants and children have distinct requirements.

Possible Advantages

To support heart health, ensure adequate EPA and DHA intake.

For those with coronary heart disease or at risk of heart attack, up to 1,000 mg of combined EPA and DHA per day is suggested.

Yet, a recent review found that adding EPA and DHA via diet or supplements had little to no effect on lowering heart attack risk.

Still, the analysis noted that fish oil can reduce high triglyceride levels in the blood — a heart disease risk factor — and it may raise “good” HDL cholesterol.

The triglyceride-lowering effects are dose-dependent; higher EPA and DHA intake produces a stronger reduction. In two trials, 3.4 grams of combined EPA and DHA decreased triglycerides by 25–50% within 1–2 months.

Fish oils may also support mood. Research suggests that EPA and/or DHA supplementation can alleviate depressive symptoms.

However, because studies use varying doses, there’s no definitive guideline for fish oil or EPA/DHA amounts for mental health.

One trial reported that 1,400 mg per day of combined EPA and DHA eased depression in young adults after three weeks, while another found 2,500 mg reduced anxiety in healthy subjects.

An analysis indicated that omega-3 supplements with higher EPA-to-DHA ratios were most effective against depression. Fish oils typically have higher EPA ratios.

Boosting omega-3 intake may also reduce inflammation, potentially easing joint inflammation.

However, a review of studies concluded that EPA and DHA supplements do not reliably help people with osteoarthritis.

Therefore, offering a specific fish oil dose for joint health is challenging.

Still, in a study of 75 individuals with knee osteoarthritis, 1,000 mg of fish oil per day — containing 400 mg EPA and 200 mg DHA — significantly improved knee function.

Interestingly, increasing the dose to 2,000 mg did not yield further improvements.

Summary

Fish oil may lower triglycerides, improve mood and support joint function — but recommended dosages differ by condition and study.

Is It Superior to Other Omega-3 Options?

Fish oil products deliver EPA and DHA — and many also include vitamins A and D.

Other omega-3 supplements might or might not contain EPA and DHA, depending on whether they come from fish, algae or plant oils.

If an omega-3 supplement is derived from sea algae, it will include EPA and DHA. These tend to be rich in DHA and lower in EPA.

Conversely, fish oil supplements often have more EPA than DHA, while plant-based omega-3s provide mainly ALA.

Although all omega-3 types offer benefits, EPA and DHA are the most impactful.

If you do not eat fatty fish regularly, fish oil supplements can raise EPA and DHA levels. But if you avoid fish entirely, an algae-based supplement is an effective alternative.

Otherwise, plant-oil omega-3 supplements will increase total omega-3 intake but are unlikely to substantially raise EPA or DHA levels.

Summary

Not all omega-3s are the same. Fish oil gives EPA and DHA, whereas most plant sources supply ALA — which converts poorly into EPA and DHA.

Final Thoughts

Extensive research supports the use of fish oil supplements.

Although definitive guidelines are lacking, 250–500 mg per day of combined EPA and DHA — which fish oil supplies well — is sufficient for most healthy individuals.

Remember that needs vary. Pregnant women, infants and children may need different amounts.

If you choose to increase your intake, pick an omega-3 supplement that provides the recommended levels of EPA and DHA.