Fish Oil & Omega-3 Benefits: An Honest Australian Guide (2026)

Fish oil is one of the best-selling supplements in Australia, found in millions of bathroom cabinets and recommended for everything from sore joints to a sharper memory. But the marketing has run well ahead of the science. Some of fish oil's claimed benefits are backed by solid research, others are genuinely mixed, and a few are barely supported at all. This guide cuts through the noise to explain what omega-3s actually are, what the evidence suggests they may help with, how much you need, and — just as importantly — who probably gets enough from their diet already.

We will also cover the practical questions the labels rarely answer clearly: the difference between fish oil, krill oil and vegan algae oil; why a 1,000 mg capsule might contain only a third of that as actual omega-3s; and what those repeating "fishy burps" might be telling you about freshness.

What Are Omega-3s, EPA and DHA?

Omega-3s are a family of essential fatty acids — "essential" meaning your body cannot make them in useful amounts, so you have to get them from food or supplements. There are three you will see mentioned, and the distinction matters when you read a label.

• radio_button_uncheckedEPA (eicosapentaenoic acid): a long-chain omega-3 from oily fish, linked to supporting normal inflammatory responses and heart and blood vessel function.
• radio_button_uncheckedDHA (docosahexaenoic acid): a long-chain omega-3 that is a major structural building block of the brain and the retina of the eye. It is especially important during pregnancy and early infancy.
• radio_button_uncheckedALA (alpha-linolenic acid): a short-chain, plant-based omega-3 found in flaxseed, chia, walnuts and canola oil. Your body can convert ALA into EPA and DHA, but the conversion is inefficient — often only a few percent — so plant sources are not a like-for-like swap for fish.

When researchers talk about the benefits of "fish oil" or "omega-3", they are almost always talking about EPA and DHA specifically. That is why the combined EPA + DHA figure is the number that matters most on any supplement.

What the Evidence Suggests Omega-3 May Help Support

This is where an honest guide has to be careful. The evidence for omega-3 is not uniform — it is strong for a couple of uses, mixed for several popular ones, and thin for others. Below we group the main claims by how convincing the research actually is.

• radio_button_uncheckedTriglycerides and heart health (stronger, but nuanced): the single most robust use of omega-3 is lowering high triglycerides. At prescription-level doses, omega-3s can meaningfully reduce triglyceride levels, which is why high-dose preparations are sometimes prescribed by doctors — but this relies on much higher doses than a standard daily capsule and should only be done under medical supervision. The picture is murkier for heart attacks and strokes in otherwise healthy people: several large, well-conducted trials have found that routine fish oil supplements do not clearly reduce the risk of major cardiovascular events in the general population. Eating oily fish a couple of times a week remains a sensible, evidence-aligned part of a heart-healthy diet — but that is not the same as a supplement.
• radio_button_uncheckedJoints and rheumatoid arthritis (moderate): there is reasonable evidence that higher-dose omega-3 may help support the management of joint symptoms in rheumatoid arthritis, with some people reporting reduced morning stiffness and joint tenderness. Evidence is weaker for osteoarthritis, where benefits are far less clear. Worth discussing with your rheumatologist or GP rather than self-prescribing.
• radio_button_uncheckedBrain, mood and eyes (mixed): DHA is a major structural fat in the brain and retina, which makes the "brain and eye health" angle biologically plausible, but plausibility is not proof. Trials for preventing cognitive decline or dementia have largely been disappointing, and evidence for everyday "brain fog" or memory is weak. For dry eye, results are mixed and a large, high-quality trial found no clear benefit over placebo. Interest in omega-3 for low mood exists, but the research is inconsistent and it is not a substitute for proper mental health care.
• radio_button_uncheckedPregnancy and infant development (specific role): DHA plays a genuine, well-recognised role in foetal brain and eye development, and requirements rise during pregnancy — many pregnancy-specific supplements include DHA for this reason. Some research suggests adequate omega-3 intake may modestly support a healthy pregnancy duration, though it is not a guarantee. Because dose, fish-species safety (mercury) and individual circumstances all matter, always discuss omega-3 with your GP or midwife rather than choosing a product on your own.
• radio_button_uncheckedSkin (limited): "fish oil for glowing skin" is a popular online claim, but the human evidence is limited and largely indirect. Omega-3s contribute to the skin's normal structure and may have a role in supporting normal inflammatory responses, but robust proof that a fish oil capsule improves the appearance of healthy skin is lacking — treat skin benefits as an "unproven maybe", not a reason to buy.

Omega-3 Benefits at a Glance: Evidence Strength

How Much Omega-3 Do You Actually Need?

The crucial thing to understand is that dose is measured as combined EPA + DHA, not as total fish oil. A common point of confusion: a "1,000 mg fish oil" capsule may contain only around 300 mg of actual omega-3s (EPA + DHA), with the rest being other fats. Always check the label for the EPA and DHA figures.

Fish Oil vs Krill Oil vs Algae (Vegan) Omega-3

There are three main sources of supplemental EPA and DHA on Australian shelves. They are not interchangeable on price, dose or suitability, so it is worth understanding how they differ.

• radio_button_uncheckedFish oil: the most common and usually the most cost-effective source. Delivers EPA and DHA in triglyceride or ethyl ester form. Best value per milligram of omega-3 for most people.
• radio_button_uncheckedKrill oil: provides EPA and DHA in phospholipid form, which some studies suggest may absorb well, and it naturally contains astaxanthin (an antioxidant). However, krill capsules usually contain less EPA and DHA per capsule than fish oil, and they cost more. The evidence does not conclusively show krill is more effective at an equivalent EPA + DHA dose.
• radio_button_uncheckedAlgae (algal) oil: made from marine algae — the original source fish get their omega-3s from. It is suitable for vegetarians and vegans and is naturally rich in DHA (with some products now also providing EPA). It is typically the most expensive option per milligram, but it is the go-to choice for those avoiding fish or who dislike fishy aftertaste.

Capsules vs Liquid Fish Oil

Both deliver the same omega-3s; the choice is mostly about practicality and dose.

• radio_button_uncheckedCapsules (soft gels): convenient, taste-free going down, and easy to dose. The downside is that reaching a higher EPA + DHA target can mean swallowing several large capsules a day.
• radio_button_uncheckedLiquid: lets you take a larger dose in one teaspoon, which suits people who need higher intakes or struggle with big capsules. Many liquids are flavoured (lemon is common) to mask the taste. Liquid has more surface area exposed to air once opened, so freshness and correct storage matter more.

How to Read a Fish Oil Label

This is the single most useful skill for getting value from omega-3 supplements, because front-of-pack numbers are often the least relevant ones.

• radio_button_uncheckedIgnore the big number first: "1,000 mg fish oil" describes the total oil, not the omega-3 content. Turn the pack over.
• radio_button_uncheckedFind the EPA and DHA figures: these are usually listed per capsule in the ingredients or supplement facts panel. Add them together — that combined total is your actual dose.
• radio_button_uncheckedDo the maths: if a capsule has 180 mg EPA and 120 mg DHA, that is 300 mg combined. To reach 500 mg you would need close to two capsules.
• radio_button_uncheckedCheck the serving size: some products quote their headline omega-3 figure per two or three capsules, not per single capsule. Read carefully.
• radio_button_uncheckedLook for a TGA AUST L number: listed complementary medicines in Australia carry an AUST L number on the label, indicating they are recorded with the Therapeutic Goods Administration.
• radio_button_unchecked"Concentrated" or "double strength": these contain more EPA + DHA per capsule, which can mean fewer capsules and better value despite a higher sticker price.

Quality, Freshness and Those "Fishy Burps"

Omega-3 oils are delicate and can oxidise (go rancid) over time when exposed to heat, light and air. A rancid product is unpleasant and may be less beneficial, so freshness is a genuine quality issue rather than a minor detail.

• radio_button_uncheckedStrong fishy burps or a fishy aftertaste can be a sign the oil has started to oxidise — fresh, good-quality oil should not taste strongly rancid.
• radio_button_uncheckedTaking capsules with food, or freezing them, can reduce burping for some people.
• radio_button_uncheckedStore fish oil in a cool, dark place, and refrigerate liquids and opened bottles where the label advises.
• radio_button_uncheckedCheck the expiry date and avoid bulk-buying more than you will realistically use before it expires.
• radio_button_uncheckedAn antioxidant such as vitamin E (tocopherol) is often added to help protect the oil from going off.

Who May Benefit — and Who Probably Gets Enough Already

Supplements make most sense for people who are not getting enough omega-3 from food. Many Australians who eat fish regularly fall into the "probably fine" camp.

May benefit from a supplement

• radio_button_uncheckedPeople who rarely or never eat oily fish
• radio_button_uncheckedVegetarians and vegans (algae oil is the relevant option)
• radio_button_uncheckedPeople with high triglycerides, under medical supervision and at the appropriate dose
• radio_button_uncheckedPeople with rheumatoid arthritis exploring symptom support with their doctor
• radio_button_uncheckedThose advised to increase DHA in pregnancy, after discussion with a GP or midwife

Probably gets enough from diet

• radio_button_uncheckedPeople who eat two or more serves of oily fish each week
• radio_button_uncheckedOtherwise healthy adults taking fish oil purely "to prevent heart disease" with no risk factors — the evidence here is weak
• radio_button_uncheckedAnyone hoping a capsule will replace an overall balanced diet rather than complement it

Side Effects and Cautions

Fish oil is generally well tolerated, but it is not free of considerations — especially at higher doses or alongside certain medications.

• radio_button_uncheckedCommon, mild effects: fishy burps or aftertaste, mild nausea, and loose stools, particularly at higher doses.
• radio_button_uncheckedBlood thinning: omega-3 can have a mild blood-thinning effect. If you take anticoagulant or antiplatelet medication (such as warfarin, apixaban, clopidogrel or regular aspirin), talk to your doctor or pharmacist before starting.
• radio_button_uncheckedBefore surgery: tell your surgeon or anaesthetist you take fish oil, as you may be advised to stop it for a period beforehand.
• radio_button_uncheckedSeafood and fish allergy: people with a fish or shellfish allergy should avoid fish oil and krill oil; algae oil may be a fish-free alternative, but check with a pharmacist first.
• radio_button_uncheckedHigh doses: very high intakes should only be taken under medical guidance, not self-directed.
• radio_button_uncheckedOther medicines and conditions: if you take regular medication or have a chronic health condition, check suitability with your GP or pharmacist before adding a supplement.

Frequently Asked Questions

Is there any real benefit to taking fish oil?

For some specific situations, yes — the strongest evidence is for lowering high triglycerides at prescription-level doses and for supporting joint symptoms in rheumatoid arthritis. For routinely preventing heart attacks in healthy people, the evidence is weak. If you eat oily fish a couple of times a week, you may already be getting what you need without a supplement.

What happens if I take fish oil every day?

Most people tolerate a daily dose well, with the most common effects being fishy burps or mild digestive upset. At sensible doses it is generally considered safe for healthy adults. Very high daily doses should only be taken under medical supervision, partly because of fish oil's mild blood-thinning effect.

Who should not take fish oil?

People with a fish or shellfish allergy should avoid fish oil and krill oil. Anyone on blood-thinning medication, due for surgery, or with a bleeding disorder should check with their doctor first. If you are pregnant, breastfeeding, or buying for a child, speak to your GP or pharmacist before starting.

What are the signs I might need more omega-3?

There is no simple at-home symptom that reliably signals low omega-3. The most practical guide is your diet: if you rarely eat oily fish, your intake of EPA and DHA is likely to be low. Routine blood testing for omega-3 is not standard in Australia, so the focus is usually on dietary intake rather than chasing a symptom.

Is there a downside to taking fish oil?

Beyond the cost and the occasional fishy burp, the main considerations are its mild blood-thinning effect (relevant if you take anticoagulants or are facing surgery) and the risk of buying a product that has oxidised. There is also an opportunity cost: relying on a capsule that may do little for you, rather than improving your overall diet.

What is the best time to take fish oil?

Take it with a meal that contains some fat, which can improve absorption and reduce burping. There is no strong evidence that morning is better than evening — consistency matters more than timing, so pick a meal you eat reliably each day and take it then.

Is krill oil better than fish oil?

Krill oil delivers EPA and DHA in phospholipid form and includes the antioxidant astaxanthin, but it usually contains less omega-3 per capsule and costs more. Current evidence does not conclusively show it is more effective than fish oil at an equivalent EPA + DHA dose, so for most people fish oil offers better value.