Fish Oil: Uses, Side Effects, Dosage + 12 Proven Benefits

In the evergrowing diet industry comes a new wave of supplements for targeting a variety of health benefits. Now, more than ever, there are new diets and dietary requirements which benefit from taking supplements as opposed to consuming the natural dietary form of the food, herb or spice. 

One of the most popular alternative food supplements out there is fish oil. It has been around for generations in its natural oily fish form and used as an effective treatment for many health concerns due to its omega-3 rich content. 

Fish oil has seen groundbreaking results for heart and blood conditions and since it hit the market as a supplement, it has expanded its popularity even further. Americans spend over $1 billion on over the counter fish oil supplements every year. 

Today, we are taking a look into why it’s so popular, how it might be able to benefit you and more:

What is fish oil?

Fish oil is one of the most common diet supplements due to its many benefits being essential for good health. Naturally, fish oil is extracted from fish tissue and is commonly consumed from oily fish such as tuna, herring and salmon for its high level of omega-3 fatty acids. Nowadays, fish oil supplements have become popular for those who do not eat fish or do not get enough consumption weekly. 

Omega-3 is not a nutrient the body can make itself, hence why it relies heavily on regular consumption to get the nutrient. From regular consumption of oily fish or fish oil supplements, you can get enough omega-3’s. A typical fish serving or supplement contains around 30% omega-3, and the other 70% is made up of other fats. Supplements in particular also contain a good dose of vitamin A and D. 

Whilst the omega-3 plant source contains mainly alpha-linolenic acid (ALA), the fish oil contains omega-3 fatty acids called docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Although ALA is an essential fatty acid, DHA and EPA are scientifically studied to prove they have more health benefits, such as reducing the risk of cardiovascular disease. 

It is important for diets to include omega-3 rich foods and supplements, like fish oil, as the Western diet consists of a lot of omega-6’s which is not so good for the body. Neither does omega-6 hold any health benefits as a high consumption of them has led to an increase in  numerous diseases. 

Now you know all about what fish oil is, let’s talk about it’s main function:

Fish oil: the main function

The World Health Organisation (WHO) recommended eating 1 to 2 portions of oily fish per week to attain its many health benefits and high omega-3 content. Similarly, you can take a daily dose of fish oil supplement to consume the same, if not more, fish oil and omega-3’s. 

The main function of fish oil is to protect the heart and blood. It has been studied for many years for its help in reducing heart and blood disease. Most studies found that fish oil can effectively reduce triglycerides in the blood by up to 50%. A high level of triglycerides in the blood is known as hypertriglyceridemia, which can lead to heart disease. 

Fish oil is most effective for reducing the risk of heart disease when made up into a prescription drug. The most common ones are Lovaza, Omtryg and Epanova, which provide around 3.5 grams of omega-3’s daily.

A higher dosage of omega-3’s shows a close correlation between reducing the risk of heart disease further. Some fish oil supplements servings of oily fish have shown results for reducing triglycerides, but the prescription drugs have shown to be more effective. 

Other functions of fish oil include improving brain function, reducing joint pain, protecting the body against other diseases and inhibiting inflammation, which we will discuss today. 

Read more : Our complete foods list that boost your brain functions

To learn more about where fish oil comes from, its history and how it was founded as an essential dietary need, here is more:

Where does fish oil come from?

Fish oil has been used for its numerous health benefits since the ancient Roman times, but has seen increased mass production and consumption since the early 1970’s. Scientists were interested in how healthy the Inuit people of Greenland were and what made their disease level so low. 

During the late 1960’s Danish scientists closely examined their lifestyle and found that the Inuit people consume a lot of fatty fish from their sea, as do the Japanese. The heavy, healthy and regular consumption of oily fish in their diets has led to the reduction in heart disease, kidney failure and helps with weight management. 

Since, fish oil has been marketed across the world to promote its health benefits. Fish oil has so many health benefits, it can be suited to a wide range of people. Those benefits include:

The 12 Benefits of Fish Oil

Over the decades there have been countless amounts of studies into the proven health benefits of fish oil. Like any dietary nutrient, there are some studies that concluded with no effective results. But today we are here to tell you about all the proven health benefits:

1 – improves heart health

Year by year, the most common cause of death is heart disease and failure. Studies by WHO demonstrate a consecutive pattern in heart disease for being the highest death cause. 

Similarly, studies show that regular consumption of oily fish reduces the risk of heart disease. There are many reasons for heart disease from developing. It can be as simple as someone’s diet or more medical concerns such as high triglycerides, cholesterol, blood pressure and a buildup of plaque. 

Although there is no sufficient evidence to show that fish oil can prevent heart attacks, there are enough conclusive results for fish oil reducing the reasons for heart disease. For example, the two omega-3’s found in fish oil, DHA and EPA, were studied to see their effectiveness in lowering blood pressure. The results showed significant reduction in blood pressure in adults who took a daily dose of fish oil. 

Fish oil and its omega-3 content has been tested on other heart disease issues such as plaque and cholesterol and results have shown to be successful and effective. 

2 – aids weight loss

Weight management is a global market and is even more so due to the obesity rate increasing each year. In the US, around 39% of adults are overweight or obese and that figure is only going to increase. 

Studies show a direct correlation between obesity and heart disease, diabetes and cancer, which is where fish oil becomes effective. Fish oil studies have proven to improve body composition and therefore aided weight loss when taken alongside exercise. A reduction in weight can help lower obesity levels and peoples body fat, which can in turn reduce the risk of fatal diseases. 

Therefore, if people are willing to take fish oil supplements or regularly eat oily fish alongside regular exercise, weight loss can be effective. Like most supplements, fish oil cannot offer a weight loss solution if no exercise is complete. The user has to work alongside the supplement and its active ingredients to see weight loss results.

3 – reduces the risk of miscarriage

On average, one in four pregnancies end in miscarriage. There have been many studies and stories about fish oil for pregnancy, early life and miscarriage. Some have shown ineffective results however, Australian studies suggest that fish oil can reduce the risk of miscarriage. 

A common disease associated with miscarriage is antiphosphilipid syndrome (PAPS), which causes clotting and results in miscarriage. This study treated 22 women with fish oil who suffered from PAPS and over 3 years, all women managed to conceive. This study has showed encouraging results to show how fish oil can reverse the role of PAPS to reduce the risk of miscarriage. 

Not only does fish oil show positive results for miscarriage, fish oil has benefits for babies throughout their early life. The omega-3’s are an essential fat for early development and growth. It is important for the woman to consume omega-3’s during pregnancy also so that the baby can benefit.

4 – may help treat mental disorders

Fish oil seems to benefit many of the body’s organs. Studies show it also has a great effect for the brain. The brain is made up of around 60%, most of that being omega-3 fatty acids. Omega-3 is an essential the brain needs in order to function properly. If the brain is deprived of these omega-3 fatty acids, it can increase the chance of mental disorders and its symptoms.

The effectiveness of fish oil is not only to reduce the impact of mental symptoms, but it can also reduce developing mental disorders, especially bipolar and schizophrenia. 

5 – reduces inflammation

Whilst inflammation is usually a defence mechanism for common infections and illnesses, in some cases chronic inflammation can occur which can cause more severe issues. Chronic inflammation is an issue that can cause obesity, heart disease and diabetes. Fish oil has anti-inflammatory properties that can help reduce inflammation can help reduce the symptoms but cannot guarantee complete treatment. 

For example, fish oil can reduce the production of an inflammatory molecules called cytokines which can is present in obese and stressed individuals. Studies suggest that the reduction of the inflammatory molecules can reduce the impact of stress for increasing obesity rates. 

Inflammation can cause many medical concerns, not just obesity, such as joint pain, stiffness, arthritis and more. For more information on joint pain and an effective omega supplement, read our review of Omega XL. Therefore, the anti-inflammatory properties of fish oil can benefit many inflammation issues. 

6 – helps improve skin

An itchy skin disease called psoriasis has shown to be improved with the help of fish oil. The application of fish oil onto the skin can help calm itchiness and reduce the appearance. For it to have effect on the skin, results have only been shown when applied directly to the skin as opposed to taking fish oil orally. 

To reduce psoriasis on a larger scale, patients can have an IV drip to help with this.

7 – improves attention and mental functions

Attention deficit disorders such as ADHD are a result of the brain being hyperactive. Seeing as the brain is made up largely of omega-3 fatty acids, regular consumption can help the brain function properly. 

Research shows that fish oil can improve your attention, mental function and behaviour in children between 5 and 12 years old with ADHD and other inattention issues. 

To avoid the chance of mental disorders, it is best for children to start fairly young with regular consumption of fish oil. Not only can it reduce the risk of developing a mental disorder later on in life, but it has shown to help reduce hyperactivity of the brain and aggression in children. 

8 – reduces allergy symptoms

Common allergies begin in unborn babies. The allergy starts when the baby is born and was once considered impossible to prevent. However, studies show how mothers who consume fish oil regularly can reduce the chance of their child having allergies. 

Similarly, consumption of fish oil during pregnancy can lower the risk of asthma. More commonly, fish oil is used for asthma which is caused by swelling of the lungs. 

Many studies have shown how fish oil can reduce the risk of asthma. Fish oil can reduce the airways hyperresponsiveness which suggests it can help an individual breathe easier, especially those with asthma or those who partake in regular cardiovascular activity. 

9 – improves bone health 

Whilst bone health is commonly associated with other nutrients such as calcium and vitamin, omega-3 fatty acids also benefit and support bone health. Omega-3 is a polyunsaturated fatty acid and research shows a link between polyunsaturated fats and better bone mineral density. 

Bone strength typically decreases with old age. A common bone disorder is osteoporosis which is where bone mass and strength is reduced and the same study shows how polyunsaturated fats play a role in building bone strength, which can slow down the process of impairment.

You can take fish oil along with other bone benefiting supplements such as calcium or primrose oil to increase the effectiveness. The benefits are not proven to work with those who already have decreased bone health or disorders, but it can improve and maintain healthy bones.

10 – improves eye health 

Like bone health, eye health can decline with age. Age declining eye health is known as age-related macular degeneration (AMD) and eating oily fish has shown to reduce the risk of AMD. These are only small studies that investigate the benefits of fish oil with eye health but there have been positive results. 

Improving eye health has no scientific guarantee, but with positive results it can be safe to say that fish oil may improve eye health and is worth taking if you are seeking its other proven health benefits.

11 – reduces menstrual cramps

Menstrual cramps are a common symptom of the monthly female hormone cycle and whilst there is no permanent treatment, supplements and vitamins can improve the impact. Along with other vitamins, fish oil is a common supplement females like to take to reduce the force of menstrual cramps. 

Fish oil can help with this issue due to its anti-inflammatory. The more inflamed the womb is, the most intense the cramps can be. Therefore, if the walls and wombs can be less inflamed, the cramps may not be as severe. 

12 – slows down the risk of kidney disease

Taking fish oil has seemed to slow down the risk of kidney disease in high risk patients with IgA nephropathy. The studies show short-term effectiveness as opposed to long-term, however the use of fish oil can slow down the impact. It also shows to have a greater impact when taken in higher doses. 

Similarly, fish oil has shown to be beneficial for those with kidney damage. Cyclosporine is a drug commonly taken to reduce organ rejection which over the years has shown to cause kidney damage. For those who are currently taking cyclosporine, fish oil studies suggest that the fish oil can prevent kidney damage. It also helps the kidneys recover after taking a course of cyclosporine. Again, these results are short-term but have shown to be effective. 

To find out a little more on how exactly this wonderful and powerful extract is made into supplements and/or into your daily diet, let’s talk a bit about the composition of fish oil:

Composition of Fish Oil

As we know it, fish oil can be consumed from oily fish or as capsules. The composition of the supplements is a little different to consuming fish in its natural form as the ingredients need to be balanced in order to be safe, pure and effective. 

Fish oil supplements come as capsules and are largely made up of omega-3 fatty acids. The two main fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the active ingredients which provide the numerous health benefits. The proteins and nutrients are pressed from the fish, which is where the oil splitting process happens. After pressing, the omega-3’s content is released and then composed into capsules. It is a simple process and ensures the ingredients to be pure.

Fish oil has numerous benefits for a variety of ages and medical conditions. Is it made safe for all ages and non-intervening conditions, but you may be wondering who exactly it is for. Here is more:

Who is fish oil for?

Fish oil is safe to consume at any age from a young child to an elderly person when it’s eaten as an oily fish. The supplement version can only be taken by a respectable age, when tablets are suitable.

Fish oil is for anyone looking to improve their health medically, physically and mentally. Due to its many health benefits, fish oil can be taken by a wide range of people. If your medical concern is listed under its proven health benefits, the fish oil is good for you to take, if you are fit and free of other existing conditions that could interfere with the nutrients.

Largely, fish oil is mostly for anyone with high triglycerides and/or heart and blood conditions. However, many people can take it if it provides more than that.

If you are unsure if fish oil will be right for you, you may wish to seek further professional advice and weigh up its pros and cons:

Pros and Cons of Fish Oil

Lowers triglyceridesIt can thin your blood
Has many proven studies that show real resultsMay lower blood pressure
Helps with cholesterol and increases HDLDiarrhea can happen with overconsumption
Protects against many physical and mental diseases and disorders

If you now wish to consume more fish oil and are unsure how much is too much, right or too little, here is a dosage guide:

Dosage: how to use fish oil?

When to start and when to stop?

With there being little to no side effects of fish oil, you can start and stop as and when you wish to. If you take other medications and/or notice side effects, you must seek medical attention immediately. Fish oil supplements, like other supplements, can interfere with other medications or weaken their effectiveness. 

What are the dosages to respect?

The recommended dosage of fish oil differs depending on age and current health state. It also depends on the form of which you consume fish oil. If taken as a supplement, dosages can vary depending on the level of DHA and EPA in the supplement.

WHO recommends taking a daily dose of 0.2 – 0.5 grams (200 – 500 mg) of combined EPA and DHA. You can increase the dosage if you require a higher percentage of fish oil for medical diseases. 

Many supplements contain around 1,000 mg of fish oil but only 300 mg of that consists of EPA and DHA, the main active ingredients from the omega-3 fatty acids. It is recommended to buy fish oil with a higher EPA and DHA content, of around 500 mg for increased effectiveness. 

Can you overdose on fish oil?

Fish oil is pretty much as safe as consuming natural ingredients as when you buy pure products, the ingredients are tested for your health. However, if you consume more than the recommended dose for a while it can increase blood pressure and bleeding. This does not happen often but has been reported before, therefore it is best to stick by the recommended dose to inhibit any dangers to your health.

Precautions to take

Many fish oil supplements do not contain what they say they do. It is best to purchase one that is 100% pure. To do so, you must buy certified products. To ensure that they are certified, they will be sealed by the Global Organization for EPA and DHA Omega-3s (GOED), who is a third-party testing company. A certified product will provide you with a guarantee that they are effective and safe to take. 

For more on precautions, the risk and side effects:

Risks and side effects of fish oil

There is little concern for side effects if a person abides by the recommended daily dosage. However, when consuming a higher dose, of 3 grams or more per day, there are a few reported side effects.

Side effects

  • May cause excess bleeding or clotting
  • Reduce the immune systems reaction and its ability to fight off infection
  • Belching 
  • Bad breath
  • Heartburn
  • Loose stools
  • May increase blood pressure

As stated, these side effects are only concerned with high doses of fish oil or for people with existing medical conditions. Before taking fish oil, those with medical conditions must seek advice to ensure it will not interfere with their medication or condition. 


Fish oil can interfere with a few different medications so it is important to be cautious if you are currently taking any medicines or prescribed drugs. Medications that can cause contraindications are:

  • Birth control pills – some contraceptive pills can breakdown the fats in the blood, which can cause the fatty acids from the omega-3’s to breakdown which will decrease its effectiveness.
  • Blood pressure drugs – fish oils benefit those with high blood pressure therefore for those who take blood pressure tablets, fish oil can decrease the level and make it too low.
  • Weight loss pills – a weight loss pill known as Orlistat, which is used to inhibit dietary fats being absorbed by the gut. Therefore, orlistat may prevent fish oil from being absorbed by the gut. To avoid this, you can take the two pills two hours or more apart.

To avoid side effects and contraindications, always respect the recommended dosage and seek medical help if you notice symptoms, have queries or are unsure if they will benefit you. 

If you would like to know a little more on where you can purchase fish oil and the most popular recommended brands, then here is all you need to know:

How to buy fish oil: the complete guide

Where to buy fish oil?

Fish oil is easily accessible from a variety of fish which can be purchased at supermarkets or fresh from fishmongers. 

If you wish to buy fish oil as a supplement/capsule and need more assistance, the best place for variety and guaranteed pure products is Amazon. Not only is there huge variety, there are certifications to prove the product is safe, many user reviews and guides.

Capsules are the most popular form of fish oil as they are easy to take and do not smell like the natural form of the food. The most popular capsules are often soft and have a gel-like and come with an outer coating. 

Always be careful when shopping anywhere in-store and online. Be sure to check the ingredients list, amount/type of omega-3, purity, authenticity and freshness to know you are getting the best product.

A few reputable omega-3/fish oil supplement brands available on Amazon are Nordic Naturals, Green Pasture, Bio-Marine Plus, Omegavia, and Ovega-3.

What price?

Fish oil prices vary from brand to brand and fish to fish. A fresh fish can cost anything from a few dollars up and the same goes for supplements. 

A good price for a pack of capsule supplements is from $15 and up. Anything that is cheap may not be the real thing and contain a low dose of omega-3. The most popular brands will sell their capsules for around $15 which has set this at a standard price.

If you would like to know what users of fish oil supplements think to their effectiveness and health benefits, below are some user reviews:

Fish Oil: reviews

User reviews are considered to be a very important aspect for a buyers decision making. Good user reviews sometimes say more about a product than its scientific background and description. To make this unbiased, we are sharing reviews of just one fish oil form, which are the best selling fish oil supplement on Amazon. 

Typically, these might be the capsules most buyers would consider as their introduction to fish oil and they have very honest and open reviews from its consumers. The reviews are for Omega 3 Fish Oil 1000mg Soft Gels by Nu U Nutrition sold on Amazon.

User testimonials

Fish oil review
Fish Oil supplement review
Omega 3 fish oil user review
User reviews of fish oil
great review on Fish Oil

Most say these capsules are 5 out of 5 stars, that they are easy to take, very affordable and show great results when you take them consistently. Many users are taking the fish oil capsules for a variety of reasons and most are satisfied. None say they are magic and can work within just a few days as fish oil is scientifically studied to show results after taking them for 14 days or more. 

If you have more questions, below are a few more facts and important to know information about fish oil:


Can I take fish oil before bed?

Generally, you can take fish oil any time of the day. Many like to take their daily dose in their morning with breakfast to ensure they take it and do not forget. Capsules and medicines are popular to take in the morning due to that reason, but it does not mean taking them later is less effective. Taking fish oil before bed has the same effect as taking them any other time of the day. It is completely up to preference, so long as you keep up your daily doses to obtain the full effect of the ingredients.

Does fish oil make you gain weight?

In some cases, fish oil can make a person gain weight. Omega-3 is a fatty acid which has anti-inflammatory properties and can sometimes interact with other medicines, as can all supplements. However, it is much more common to lose weight whilst taking fish oil as opposed to gaining it. Making sure you keep up with a balanced diet and exercise routine will ensure you do not gain weight unexpectedly. 

Can fish oil damage kidneys?

Fish oil is commonly used as a way to slow down kidney disease from developing, especially in high risk patients that have an existing kidney disease called IgA nephropathy. Therefore, it is in most cases good for the kidneys. 

However, over consumption may lead to damaging effects on the body. Also, it is advised not to take them for too long of a period. Taking fish oil supplements for over 4 years consecutively may lead to damaging kidneys or other parts of the body. 

Does fish oil raise cholesterol?

Cholesterol is often treated and managed with the use of fish oil. Fish oil helps increase HDL which is the good cholesterol in the blood. It is used as a method to lower cholesterol but has more of a significant effect on increasing HDL over lowering LDL, known as the bad cholesterol. 

Fish oil is not the only effective supplement on the market and there are many out there with more significant results, but it is generally good for cholesterol. 

With that, let us tell you our thoughts on fish oil, which you can use as a take home message:


Although fish oil as a component molecule, in the form of a capsule, has shown to be effective for benefiting many health conditions, the real results are sometimes questionable in comparison to the real food. 

The supplement form of fish oil does not hold any more benefits than the food itself and if anything, the natural food form holds more nutrients as it has avoided the processing and manufacturing method. The fish itself contains nutrients such as key vitamins and  minerals that generally do not exist in the supplement. Most capsules contain just the DHA and EPA components which are the two active ingredients, but your body can benefit from those as well as other nutrients when eaten in the dietary way. 

However, both are effective and the fish oil supplement is very beneficial for those who do not eat fish out of choice or due to allergies. Both are a great source of omega-3 fatty acids which is what holds the health benefits. It all depends on preference, what your doctor may recommend and what you think will work best for you. 

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