Omega-3 Fish Oil: Benefits, Dosage and How to Choose a Supplement
Omega-3 fatty acids are essential fats: your body needs them but can only make small amounts, so they have to come from food or supplements. Omega-3 is one of the most searched supplements in Saudi Arabia, yet the labels can be hard to compare. This guide explains what omega-3 does, what the research actually says, and how to choose a good omega-3 fish oil supplement.
What is omega-3?
There are three main types of omega-3:
- EPA (eicosapentaenoic acid), found mainly in oily fish
- DHA (docosahexaenoic acid), also found in oily fish, and a building block of the brain and the retina of the eye
- ALA (alpha-linolenic acid), found in plants such as flaxseed, chia seeds and walnuts
Your body can turn some ALA into EPA and DHA, but only a small amount. That is why most of the research, and most supplements, focus on EPA and DHA from fish or algae.
Omega-3 benefits: what the research says
Heart health
People who eat oily fish regularly tend to have a lower risk of heart disease. High doses of EPA and DHA can lower blood triglycerides, and prescription-strength omega-3 is used for this under medical supervision. However, large trials of standard fish oil supplements in generally healthy people have shown mixed results for preventing heart attacks and strokes. Omega-3 supports a heart-healthy diet; it does not replace one.
Brain and eyes
DHA is a major structural fat in the brain and eyes. Getting enough is especially important during pregnancy and breastfeeding, when it supports the baby's development. Our guide to the best pregnancy vitamins covers this in more detail. Evidence that supplements improve memory or focus in healthy adults is still limited.
Joints
Some studies suggest omega-3 may modestly ease joint stiffness and tenderness in people with rheumatoid arthritis. If joint comfort is your goal, you can also explore our bone, joint and cartilage range.
Skin and hair
Omega-3 fats are part of healthy skin cell membranes, but there is little strong evidence that supplements improve skin or hair on their own. A balanced diet and a good skincare routine matter more.
The best omega-3 foods
Many health organisations recommend eating oily fish about twice a week. Good sources include:
- Salmon, mackerel, sardines, anchovies and trout
- Tuna (lower amounts than oily fish)
- Flaxseed, chia seeds, walnuts and hemp seeds (ALA only)
- Omega-3 enriched eggs
If you rarely eat fish, a supplement is a practical way to get EPA and DHA.
Fish oil, krill oil, cod liver oil or algae oil?
| Type | What to know |
|---|---|
| Fish oil | The most common and usually the best value. Strength varies widely between brands. |
| Krill oil | Smaller capsules and less fishy aftertaste for some people, but usually less EPA and DHA per capsule. |
| Cod liver oil | Also contains vitamins A and D. Count these towards your total intake, and check with your doctor before using it in pregnancy. |
| Algae oil | A vegan source of DHA and EPA, made from the algae fish get their omega-3 from. |
What about omega 3-6-9?
Most diets already contain plenty of omega-6 from vegetable oils and nuts, and the body can make omega-9 itself. For most people, a plain omega-3 supplement gives more EPA and DHA for the money than a 3-6-9 blend.
How to choose an omega-3 supplement
- Check the EPA and DHA, not the fish oil. A capsule labelled "1000 mg fish oil" may contain only around 300 mg of EPA and DHA combined. Look at the supplement facts panel for the actual amounts per serving.
- Look for purity testing. Good brands test for mercury and other contaminants, and some carry independent certifications.
- Freshness matters. Omega-3 can oxidise. A strong fishy or rancid smell when you open the bottle is a sign it may be past its best.
- Consider the capsule size. Concentrated formulas give more omega-3 in fewer or smaller capsules.
- Check for allergens. Avoid fish and krill oils if you have a fish or shellfish allergy.
For example, NOW Foods Ultra Omega-3 Fish Oil is a concentrated option, and Sporter Omega-3 Fish Oil 1000mg is a popular everyday choice. If you train regularly, browse our sports fish oil and omegas range.
How much omega-3 should you take?
There is no single official daily amount for EPA and DHA. Many health authorities suggest around 250 to 500 mg of EPA and DHA combined per day for healthy adults, which you can get from two portions of oily fish a week or a standard supplement.
Higher doses are sometimes recommended for specific conditions, but only take more than the label suggests if your doctor advises it.
Best time to take omega-3: with a meal that contains some fat. This can improve absorption and reduce fishy burps. Morning or evening both work; consistency matters more than timing. Many people take it alongside vitamin D, which is also fat-soluble.
Omega-3 side effects and precautions
- The most common side effects are a fishy aftertaste, burping, heartburn and loose stools. Taking it with food or freezing the capsules can help.
- High doses can affect blood clotting. Speak to your doctor or pharmacist before taking omega-3 if you use blood thinners or are having surgery.
- If you take a multivitamin or cod liver oil, check the total vitamin A and D you are getting. Our guide on whether you need a multivitamin every day explains how to avoid doubling up.
Omega-3 for kids
Children who don't eat fish may benefit from a child-friendly omega-3, often in liquid or gummy form. Choose a product made for their age, and check with your paediatrician first. You will find options in our kids vitamins range, and more tips in our article on supporting your child’s immune system.
Frequently asked questions
How long does omega-3 take to work?
Omega-3 levels in your blood rise over several weeks of daily use. Any effects are gradual, so give it at least two to three months.
Is it better to eat fish or take fish oil?
Eating fish gives you omega-3 plus protein, vitamin D, selenium and other nutrients, so food comes first. Supplements are useful if you rarely eat oily fish.
Can I take omega-3 with other supplements?
Omega-3 is commonly taken with vitamin D and magnesium. If you take several supplements or regular medication, ask your pharmacist to check for overlaps or interactions.
Explore the full omega-3 and fish oil range at Avnzor, or ask our pharmacists for help choosing the right one for you.
This article is for general information only and is not a substitute for advice from your doctor or pharmacist. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease.
