This site has limited support for your browser. We recommend switching to Edge, Chrome, Safari, or Firefox.
Expert Tips

Is omega-3 fish oil a blood thinner?

Understanding Omega-3 and Blood Thinning

Omega-3 is a natural, polyunsaturated fat that the body needs, but can’t make on its own - it must come from the food we eat. Topping up your own levels by eating more oily fish like salmon or sardines is a great idea for general good health, as is taking a supplement if you don’t like the taste or worry about pollution.

But when it comes to supplements, should everyone be taking fish oil in concentrated doses? After all, our Life & Soul fish oil  contains 3,500mg of omega-3 in just one single teaspoon, while four of our tiny Life & Soul capsules contain 1,460mg of omega-3, making them two of the strongest fish oil supplements on the market.

The short answer to this is no. People who are on blood thinning medication, perhaps because they’re suffering from heart disease, are advised to avoid certain supplements and one of those is omega-3 fish oil. But is that because omega-3 can thin your blood even more? Or stop the blood thinners from working as effectively?

The idea that omega-3 could thin blood started in the 1970s when omega-3 was first “discovered” by researchers studying the Inuit in Greenland. The scientists thought omega-3 was able to make platelets less sticky and could play a part in preventing blood clots.

Because of this belief, omega-3 was quickly added to the list of things you shouldn’t take before surgery in case it promoted excessive bleeding after an operation. But recent studies have contradicted this entirely, with some showing no increased risk of post-operative bleeding with fish oils.

So while the jury’s out as to whether omega-3 actually has any anti-clotting or blood thinning effects at all, most doctors (wisely) err on the safe side when it comes to advising their patients who are taking blood thinning medication.

Related Products

 bare biology life & soul omega 3 liquid pack shot on white background
bare biology life & soul omega 3 daily capsules pack shot on white background

Can I take omega-3 and blood thinners?

It’s always worth asking your doctor for advice if you’re unsure. But those taking warfarin or aspirin prescribed by their doctor are typically advised not to take omega-3 fish oil in its concentrated form as a supplement.

But the surprising thing is, it’s not just omega-3’s potential effects on blood thinning that make it unwise to take if you’re already on a blood thinning medication.

It’s also really important that patients on blood thinners keep their diets stable without attempting any big changes, as the way you eat can make a big difference in how your body responds to the drug. You shouldn’t try any new diet, take any new supplements or even attempt to lose weight without speaking to your doctor first if you’re being prescribed something like warfarin.

What do blood thinners do?

Blood thinning drugs keep blood moving smoothly through veins and arteries. They can stop blood clots from forming and may even help to break up any existing clots.

This is important because, although blood clotting is a natural, necessary process, sometimes the blood can clot too much, putting people at risk of health complications. Blood clots can travel to the heart, lungs or brain, where they could cause a heart attack or stroke.

Who takes blood thinners?

You may be given blood thinners if you have a congenital heart defect, suffer from angina or have heart or blood vessel disease. Blood thinners may also be given if you’ve had surgery to reduce the risk of clots forming.

What are blood thinners?

There are two types of blood thinners available and they’re known as either anticoagulants or antiplatelets. And funnily enough neither actually ‘thin the blood’, but instead work in different ways to stop clots from forming.

Anticoagulants such as heparin and warfarin slow down your body's process of making clots. They’re usually prescribed by a doctor when your body is known to be making blood clots already, or you have a medical condition known to promote clots, such as atrial fibrillation. This is a common heart rhythm disorder that increases the chances of blood clots and strokes.

Antiplatelets such as aspirin are weaker than anticoagulants, but work by keeping your platelets from getting too “sticky” and clumping together, which is the very beginning of a blood clot.

Why do bodybuilders take fish oil pills?bare biology mums and bumps omega 3 capsules held by a pregnant woman

What other foods or supplements should not be taken with blood thinners?

It’s not just omega-3 that should be avoided. Fish oil is just one in a long list of contraindications to blood thinning medication that include certain antidepressants and anti-inflammatories, as well as herbal supplements such as ginseng, dong quai or grape seed extract. They’re also known to interact with certain foods such as cranberry juice, vitamin k and alcohol.

People taking prescription blood thinners should not use any supplements or herbal remedies without talking to their doctor first and that includes omega-3 fish oil. Even though they are natural, some may affect the way the drug works in the body.

If you’re taking blood thinners, it’s vital you follow the instructions to the letter and make sure your doctor knows about all of the medicines and supplements you are using. This is because certain products can either stop the blood thinners from working effectively, increasing the risk of dangerous clotting, or they may add to the thinning effects to further increase the risk of bleeding, either from wounds or even internally, through things like stomach ulcers.