Your Fish Oil Is Rotten: Find Out How To Pick The Right One

Your Fish Oil Is Rotten: Find Out How To Pick The Right One.

It’s everywhere. It’s ubiquitous! (Favorite word alert.) You can purchase it at Rite Aid, Costco, Super supplements and I recently saw “fish oil shots” at the checkout in a gas station.

Clearly, we are being told that fish oil is a tremendously important supplement. So important, in fact, we all not only need to be taking it but we have to be very careful to be taking the right one.

I know, I know, you have questions. Go ahead.

“So I want to know why fish oil has become so popular?” Well, put simply, without going into all the gory scientific details, fish Oil (or more appropriately DHA, and EPA) have a hand in optimal operation of brain functioning, immunity and cardiovascular health. Some would argue that these essential fats play a role in almost every physiologic function in the body.

“If EPA and DHA are so important why are these nutrients not provided from our food?” Well, they are, or rather they were. You see back in the day when we hunted and gathered our food we ate largely game meats (grass fed) and wild fish, both hugely rich in omega three fats. We also ate more of the animal. The cartilage and the fat were super rich in omega threes. Now we have grain fed and farmed the begeezus out of our food sources so they, and subsequently we, are grossly deficient in the rich omega three fats our bodies so desperately rely on.

Omega threes are an “essential” nutrient, which means we cannot produce it within our bodies. We have to get it from our nutrition, but sadly our nutrition is devoid of this lovely fat source, and we now find ourselves in the fall-out of being omega three deficient. The second reason we are so out of balance with the fat balances in our body is that back in the fifties the advent of processed, boxed and canned convenience foods rolled on the scene. We thought we’d died and gone to heaven. Sugary cereals and overly processed grains meant we could conveniently fill every plate, at every meal, with this low cost “great-tasting” food. The problem was these foods were either devoid of healthy fats altogether, (think “fat-free”) or they had fat, but the wrong kind. Omega 6s and 9s are necessary for our bodies to work optimally but at a “trickle” not a “flood.” We have been flooding our systems with these terribly inflammatory precursors (6’s and 9’s) for several decades now, and we have arthritis, asthma, cancer and dementia populations to prove it.

“So now I know about the importance of omega three fats. Why not just eat more wild fish and game?”  Excellent deduction, Poodle. However, smart people like Chris Kesser and Mercola agree that even if we stuff our faces with wild salmon, these fish are often more deficient in omega 3’s than their ancestors which means we are not getting the proper amount. Also, there is the issue of heavy metals and other toxins in the fish. So yes! Eat more fish and game in your diet but the recommendation is clear. We ALL need to be supplementing with pure fish oil.

Important Note: Don’t hear what I am not saying. You still need to eat fish and game meat. There are other nutrients in the whole animal that allow you to digest and absorb your fish oil more effectively. One scientist’s recommendation is to always take your fish oil with an animal protein so the nutrients in the animal product can help you absorb your fish oil supplement more effectively.

“I’m all good. I take flax.” Hold on cowgirl, or cowboy. Flax is comprised of a precursor to EPA and DHA. It is called ALA (Alpha Lipoic Acid). There is a conversion method in the body to transition ALA to EPA and DHA, which is why vegetarians have been saying they can just take flax for their omega three source. The problem is that this conversion is poorly executed and very little gets through to the DHA/EPA form. Some would argue it is negligible.

[Tweet “”I’m all good, I take flax.” WRONG. “]

“So now I understand why I must take fish oil. What brand should I buy?”   I often tell patients I am picky about where you purchase your supplements because of packaging, capsulation process and type of ingredients. But when it comes to fish oil, I am militant. There are very few fish oils on the shelf at present that can pass my stringent requirements. (They should be your stringent requirements too! Keep reading; you’ll understand why.) Here is the issue. A bad, or poor quality fish oil can be worse for you than not taking a fish oil at all. A bad fish oil can be inflammatory and toxic to your system. I would argue you probably already are a little inflammatory and toxic due to our western diet and environmental toxins, so you don’t need to be throwing gas on the fire. Below is a breakdown of the process by which I judge a fish oil. If this is a little too detailed for you, skip to the bottom for my recommendations.


“How do I size up a fish oil product?” Have you ever eaten Foie Gras? If you talk to a chef it is one of the hardest things to make because it separates if you look at it wrong. The flavors are entirely dependent on the proper steps being taken during preparation. Fish oil is similar. If any of the particular steps are skipped, the quality of the end product will suffer. So here are the important factors for fish oil processing and packaging in no particular order.

  • Bottling: Two things to consider here. Where was the fish oil bottled? At the source. Good. Shipped in vats and bottled somewhere cheaper? Bad. Too much opportunity for a fish oil to turn rancid. Fish is an unstable little mother. You have to be very careful with it during processing. The second point is the bottles need to be dark glass. Plastic is not a good substrate for fish oil for potential leeching issues.
  • Extraction process: How do you get the oil from the fish? What is done with it immediately after extraction? James Chestnut DC tells us it is essential to infuse antioxidants at the time of extraction to help preserve the oil naturally. I am pretty sure your drugstore brand might have skipped this step.
  • Shipping: As mentioned in point one the fish oil should not be shipped until it has been bottled and sealed. Many brands ship their oil in vats to save cost. The more you move a fish oil the more risk of light exposure and potential for break down.
  • Fish source: What kind of fish should we be using? That is a hot topic because the krill oil producers want you to think everything else is crap and the cod liver oil producers say the same thing. Here is the science. When a fish is “bigger” (cod, salmon) it had to feed on a fish that ate a fish that ate a fish. If any of those fish had any heavy metals or toxicity it will bio-accumulate all the way to the “big fish” one might use for a fish oil. I would rather get my fish oil from the bottom of the chain. Sardine, mackerel,  and anchovies, in my opinion, are the best sources for fish oil.
  • Pharmaceutical grade: What does “pharmaceutical grade” mean? Regular supplements on the shelf have a minimal amount of evaluation and screening before they can be placed on for sale. Once tested prior to labeling the product is not tested for content again unless there is some complaint. If you are purchasing a pharmaceutical grade supplement it has to be batch and lot tested regularly. There are strict regulations it must adhere to that are consistent with your prescription medications regulation policies. Bottom line – It is another “check in place” to assure you, the consumer, that you are getting what you think you are purchasing. My recommendation is that you stick to a pharmaceutical grade fish oil if at all possible. I have listed two at the bottom of this post. I have also listed two over the counter brands that I think are the best you can buy if you are choosing to not go with the pharmaceutical brand.


“How much should I take?” – There is no standardized dosing schedule for fish oil. One of my mentors Dan Murphy DC literally takes a shot glass full every day! He believes we are so deficient in omega three, you really can’t take too much. Several sources say 1000-1200mg combined EPA/DHA. Zinzino brand recommends that you take .15ml for every KG of body weight. Honestly, there has been no research that I can find to suggest you could take too much. But I suggest speaking to your natural health care provider regarding how much they would recommend for your personal health profile.

 “I hate taking fish oil. It smells and I burp it up.” WARNING, WARNING, WARNING!! If your fish oil stinks or tastes fishy or comes back up on you that is a sure sign that it has turned bad. Throw it in the garbage and buy a better quality product immediately. You would never eat a lovely cooked salmon sitting in front of you if it smelled turned. Why would you ingest a supplement that smells rotten? And if it says, “enteric coated” RUNNNNNNN. That simply means the manufacturer said the following behind closed doors. “We know our product is low-quality crap but we are going to cover it in something so you can’t smell or taste how rancid it is.”

[Tweet “You would not eat a fish dinner that smelled rotten…”]




This week consider starting on fish oil. If you have one you have been taking make sure it is a good quality brand meeting the criteria outlined above. If you are not sure what brand to take, see the suggestions below.



The two fish oils I recommend: 



If you have to buy over the counter:



If you liked this post you will love these:




The Fish Oil Smack Down

Health Benefits Of Fish Oil

Why Fish Stomps Flax

Innate Choice Fish Oil Article

Ultimate Guide To Omega 3




19 Responses

  1. This is such a great article. I recently found one of my capsule was broken and didn’t have anything inside. Every time I take them, they smell very fishy. I already finished the whole bottle though. This is very helpful . I am going to use this knowledge to my next purchase. Thank you for sharing such a great info.

  2. WOW!! I love your site- what a wealth of information. I totally stopped taking fish oil bc it stunk. So, happy to understand what a good fish supplement should look like and all the sources I can find the oils from to add to my diet!!

    1. Thanks, Mama Munchkin! I look forward to hearing how you do now that you will be taking a better oil!

  3. Hey Heather, thank you for this pot of gold!! Seriously, what a breath of fresh air you are!
    I recently stopped taking fish oil because it was so stinky!!! I honestly cannot understand why I believed that all fish oil supplements were the same. Heading to your recommendations now! Thanks so much for sharing <3

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About Dr. Denniston

Dr. Denniston is a wellness strategist for elite leaders and their teams, bridging the connection between personal well-being and professional success. She provides custom solutions for burnout and stress and facilitates cohesive habit-training strategies that maximize vitality, productivity, and resilience.

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