How to Find the Best Fish Oil Supplement

woman holds a capsule with vitamin E, fish oil. white background, focus on the capsule

Fish oil is one of the most commonly used dietary supplements. It’s rich in omega-3 fatty acids, which are generally important for female health, performance, and recovery due to their proven anti-inflammatory properties. If you don’t eat a lot of oily fish (like herring, tuna, anchovies, and mackerel), taking a fish oil supplement can provide your body with some foundational, omega-3 support.

Choosing the best fish oil supplement doesn’t sound like a very complex task. But it actually is!

In recent years, the critical importance of omega-3 fatty acids has become widely recognized. In response, supplement manufacturers are now marketing dozens of different omega-3 products in the form of both capsules and liquids. Some are extracted from marine sources such as cod liver, krill, or green mussels. Vegetarian options include those that come from algae or spirulina; or seed oils like chia, flax, and sesame.  Each product will have a different formulation and provide a different amount of omega-3’s per serving, and number of servings per bottle.

Each product will also likely claim to be “the best.”  And each product will be priced differently. Evaluating product features and price variables can be confusing, leaving even the most supplement-savvy shopper overwhelmed and defaulting to the least expensive brand.

Luckily, there is a much better way to select the best fish oil supplement. In fact, you can evaluate the quality and effectiveness of ANY omega-3 supplement by simply asking the following three questions:

1.  Is the product free of chemicals and pollutants?

And is a certificate of purity available for each product lot available?  While almost every essential fatty acid product on the market claims to be “chemical-free,” this isn’t always the case. The Mateel Environmental Justice Foundation recently tested about 15% of fish oil supplements on the market and found harmful PCB’s in all of them. This research suggests that some of the world's largest producers of omega-3 fish oil supplements, including those manufactured by chain store pharmacies, are selling potentially toxic products to the public.   

When selecting a fish oil supplement, do not compromise on purity. If each and every lot of the product has not been independently tested for mercury, lead, arsenic, cadmium, and other toxins by a certified independent lab, it may be tainted by heavy metals and/or other toxins.

2.  How was the oil used in the product processed?  

Fish oil is a highly unstable product. It can be damaged quickly by exposure to air, light, and heat. Most supplement manufacturers use heat and chemicals (usually hexane) in their production process in order to create a product that can sit on a shelf for months without spoiling.  Unfortunately, this type of processing exposes the fragile oils to oxygen, light, and heat which oxidizes (damages) them and creates a toxic by-product called a pro-oxidative fat. While most fish oil producers remove many of the oxidized by-products before selling them, their clean-up process is not 100% effective. While some manufacturers add vitamin E to prevent the oils from being harmed by further oxidation, most use alpha-tocopherol—a cheaper, less effective antioxidant.

What happens to a fish oil that’s not processed or protected properly?  It not only becomes ineffective, but harmful. When oxidized, fish oil converts into lipid peroxides which can damage the membranes of every cell in the body. Recent research conducted by the New Zealand Crop & Food Research Institute indicates that many big name fish oils contain oxidation by-products, despite being well within their “sell by” dates. Keep in mind that a fish oil will smell rancid only during its latest stages of oxidization. During its initial breakdown, it may have little or no aroma, but still be less than fit for human consumption.  

If a fish oil supplement comes in an enteric coated capsule, is not refrigerated, comes in a clear bottle or does not contain a potent, natural antioxidant (such as vitamin E or rosemary oil), these are red flags; there’s a good chance that the product may be rancid.

You can perform a test for freshness by biting into the capsule in question. If the oil inside tastes fishy and produces an after taste or causes burping, then it’s probably gone bad.

3. Does the product provide enough essential fatty acids?

Ignore the “recommend dose” listed on the product label. It’s not going to be accurate. You will need to determine your actual dosing needs based on the amount of EPA/DHA (eicosapentaenoic acid and docosahexaenoic are the specific, omega-3 fatty acids found in cold water fish) in each capsule or serving of the product.  Many women require a starting dose of at least 2000mg of combined EPA/DHA to effectively raise their omega-3 levels. So you’ll want to find a product that contains at least 500mg of EPA/DHA per capsule (or tablespoon) in order to keep your dose manageable.

In order to keep product costs and retail prices low, the actual amount of EPA/DHA contained in a serving may be low. As a result, the necessary dosing of many products may be anywhere from six to ten capsules a day. The source of the oil should also be considered. While algae, krill, green mussel, and flax oils are easily absorbed and used by the body, their EPA/DHA dosing per capsule is very low.

Here are some additional points to consider when purchasing any omega-3 supplement:

* The product should be packaged and stored in a light-blocking container.
* The product should be free of fillers, enteric coatings, and any unlabeled or non-specific oils.
* The product should come in either an ethyl ester or triglyceride form, which will be absorbed up to 30% better.
* How fresh is the product? Does it have a lot number and date?
* Can you identify the product’s source? Have the fish harvested for the product been sustainably caught?

Are you currently taking a fish oil supplement? What made you decide to start and what criteria did you use to select the product you use? Please share your personal experience in the comments section below.