There is no best time of day to take fish oil supplements. However, evidence suggests that people absorb omega-3 fatty acids more effectively when taken with a meal that contains dietary fat.

This comes from a study in Current Opinion in Clinical Nutrition and Metabolic Care.

Fish oil is a major source of omega-3 fatty acids, which may have a number of health benefits.

In this article, we will discuss when people should take fish oil, how to take it, dosage, and any health benefits and side effects.

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There is no significant benefit to taking fish oil at a specific time of day. However, people may wish to take fish oil with a meal that contains dietary fat.

A 2019 study on omega-3 found that taking an omega-3 concentrate with food that contains fat increased bioavailability, making it easier for the body to absorb.

Additionally, an older 2015 study found that taking omega-3 fatty acids with a low fat meal reduced absorption.

Both of these studies looked at omega-3 fatty acids specifically, so the results may not apply to people taking fish oil. Additionally, the amount of omega-3 in fish oil can vary, depending on factors such as the type of fish, and the brand.

People can take fish oil capsules with water during a meal. If a person typically does not eat much fat at breakfast, they may wish to wait until lunch or their evening meal before taking it.

Some people experience gastrointestinal side effects when taking fish oil. If a person experiences this side effect, they may find it helpful to split their fish oil into two doses and take them at different times of the day.

People who split their dose in half may need to take each one at different mealtimes.

Researchers have found it difficult to define an optimal amount of omega-3 fatty acids to get per day.

The American Heart Association (AHA) recommend adults take between 500–1,000 milligrams of omega-3 per day. However, other countries and organizations recommend different doses.

The Office of Dietary Supplements (ODS) note that while some types of omega-3 have no official recommended dose, alpha-linolenic acid (ALA) is an exception. This table shows the recommended daily amounts by age and sex:

AgeALA intake in grams (g)
Below 12 months old0.5
1–3 years0.7
4–8 years0.9
Males aged 9–13 years1.2
Females aged 9–13 years1.0
Males aged 14 years and over1.6
Females aged 14 years and over1.1
During pregnancy1.4
During breastfeeding1.3

The amount of ALA in omega-3 supplements can depend on the type of supplement and the manufacturer. Read the product label to determine how much a supplement contains.

Omega-3 fatty acids may have a positive effect on human health in a number of ways. Research into its benefits is ongoing, but there is evidence that it may:

  • lower the risk of developing Alzheimer’s disease, dementia, and other cognitive function disorders
  • improve the health of babies and slightly increase birth weight
  • reduce the risk of age-related macular degeneration, which causes vision loss
  • protect heart health and lower triglyceride levels
  • reduce the symptoms of rheumatoid arthritis

However, many studies on omega-3’s health benefits focus on getting these fatty acids from fish and seafood, rather than from fish oil capsules. If a person is thinking of taking fish oil for a health condition, they should speak with a doctor first.

Some specific conditions that may benefit from a higher intake of omega-3 include:

Cardiovascular conditions

According to a 2015 review, there is some evidence that consuming omega-3 fatty acids may help prevent or manage cardiovascular conditions. Omega-3 fatty acids may help reduce triglyceride levels in the blood and reduce the risk of cardiovascular death.

Omega-3 fatty acids may also have antiarrhythmic effects, which means they help a person’s heart beat in a regular pattern. The effect that omega-3 fatty acids have on arrhythmia may significantly reduce the risk of fatal ventricular arrhythmias.

However, more recent studies show that there may not be a clear benefit to taking omega-3 to prevent adverse effects of cardiovascular conditions. There is also some evidence that taking statins at the same time as omega-3 fatty acid supplements may reduce their protective effect on cardiovascular conditions.

Scientists need to carry out more research on omega-3 and its relationship with preventing or managing cardiovascular diseases.

Inflammatory conditions

Some studies have shown that a high omega-3 intake can reduce the risk of inflammatory disease mortality.

Some have also found that omega-3 fatty acids are beneficial for people with Crohn’s disease and ulcerative colitis, two types of inflammatory bowel disease.

However, there is no clinically significant evidence on whether omega-3 fatty acids help prevent relapses for people with these conditions.

Colon cancer

Several in vitro studies show that omega-3 fatty acids have an effect on colorectal cancer stem cells (CCSC). CCSC have a long lifespan and can self-renew, leading to colon tumors.

CCSC can lead to cancer relapse and chemotherapy resistance. Omega-3 fatty acids may stop CCSC from growing and may reduce chemotherapy resistance.

Prostate cancer

Omega-3 fatty acids may have several positive effects with regards to prostate cancer, although research on this is mixed.

Several studies have found that consuming fish or omega-3 fatty acids reduces the risk of developing prostate cancer, including aggressive forms.

However, other studies suggest that there is no clear benefit to consuming omega-3 fatty acids to prevent prostate cancer.

Side effects of fish oil supplements are usually mild. They include:

  • unpleasant tastes
  • bad breath
  • headache
  • heartburn
  • nausea
  • diarrhea
  • bad-smelling sweat

Additionally, omega-3 supplements can have an adverse interaction with drugs that affect blood clotting.

People should contact their healthcare provider to ensure it is safe for them to take a supplement before trying it.

Some evidence suggests that taking supplements that contain omega-3 with a meal that contains fat can increase absorption. As a result, people may wish to take fish oil at breakfast, lunch, or dinner. However, there is no correct or incorrect time to take it.

Always speak with a doctor before starting a new supplement. If a person experiences side effects, they may benefit from splitting their dose in two.