To reach the required dose of EPA for treating certain conditions such as depression, CVD or CFS/ME you would need to take approximately 1-2 grams of ‘free EPA’ daily. Even with a concentrated omega-3 fish oil supplement, offering 180 mg excess EPA over DHA, this would require 10-20 capsules daily – significant in terms of volume and cost, and not efficient in terms of uptake in the body as our capacity for fat absorption is limited. The most effective and efficient way to ensure high EPA uptake in the body rapidly is to supplement with pure EPA for a minimum of 3-6 months.
Most vegan omega-3 supplements are made from seaweed, one of very few plant sources of both EPA and DHA. If you’d rather skip the pills, the real thing provides omega-3s as well as vitamin K, vitamin C, niacin, folate, and choline. Seaweed can be eaten raw (look for it at your local organic or Asian market) or dried — try Annie Chun’s Organic Seaweed Snack, which comes in individual packs and is available in several delicious flavors.
Fish oil has been shown to have a direct electrophysiological effect on the myocardium. Initial experience with animal ischemia models demonstrated that the ventricular fibrillation threshold was increased in both animals fed or infused with omega-3 FA.23,24 This progressed to a demonstration, on a cellular and ion channel level, that omega-3 FA reduce both sodium currents and L-type calcium currents.25–29 It is hypothesized that during ischemia, a reduction in the sodium ion current protects hyperexcitable tissue, and a reduction in the calcium ion current reduces arrhythmogenic depolarizing currents.30
Cochrane lead author, Dr. Lee Hooper from the University of East Anglia, UK said: “We can be confident in the findings of this review which go against the popular belief that long-chain omega 3 supplements protect the heart. This large systematic review included information from many thousands of people over long periods.  Despite all this information, we don’t see protective effects.

An animal study involving the omega-3 ETA discovered that subjects experienced a drop in overall inflammation similar to that caused by NSAIDs (non-steroidal anti-inflammatory drugs), but without the dangerous gastrointestinal side effects. The study authors also pointed out that eicosapentaenoic acid seems to be even more potent than the conventional omega-3s found in fish oil supplements (EPA/DHA). (56)
Omega−3 fatty acids, also called ω−3 fatty acids or n−3 fatty acids,[1] are polyunsaturated fatty acids (PUFAs).[2][3] The fatty acids have two ends, the carboxylic acid (-COOH) end, which is considered the beginning of the chain, thus "alpha", and the methyl (-CH3) end, which is considered the "tail" of the chain, thus "omega". One way in which a fatty acid is named is determined by the location of the first double bond, counted from the tail, that is, the omega (ω-) or the n- end. Thus, in omega-3 fatty acids the first double bond is between the third and fourth carbon atoms from the tail end. However, the standard (IUPAC) chemical nomenclature system starts from the carboxyl end.
The human body does not produce significant amounts of EPA or DHA on its own, so you must get these important nutrients from the foods you eat and the supplements you consume. If you’re looking to get the heart health benefits of omega-3s, go straight to the source of EPA and DHA. EPA and DHA are naturally found in marine sources, including fatty fish – salmon, tuna, mackerel, herring – shellfish, and marine algae.
As with other supplements, when it comes to quality, you get what you pay for. Life Time sources its omega-3 fish oil (both capsules and liquid) from sustainable fisheries off the coast of Chile. We only use oils from small, cold-water anchovy, sardine, and mackerel. It’s molecularly distilled to be sure it’s free of mercury, PCBs, and heavy metals. If your fish oil brand doesn’t name the species of fish it’s sourced from, or it lists larger, predatory species, the quality and purity of the oil could be less than optimal.
In a U.K. study, children of mothers who ate more than 12 ounces a week actually scored better on tests of verbal I.Q., social behavior, and development and communication than children of mothers who ate none. In the Seychelles Islands, where people average 12 fish meals -- not ounces -- a week, there are no reports of links between mercury exposure and poor outcomes in children. These studies suggest that eating less than 12 ounces of fish each week could do more harm to a child's developing neurological system than mercury poisoning.
Fish oil is also used for diabetes, prediabetes, asthma, a movement and coordination disorder called dyspraxia, dyslexia, eczema, autism, obesity, weak bones (osteoporosis), rheumatoid arthritis (RA), osteoarthritis, psoriasis, an autoimmune disease called systemic lupus erythematosus (SLE), multiple sclerosis, HIV/AIDS, cystic fibrosis, gum disease, Lyme disease, sickle cell disease, and preventing weight loss caused by some cancer drugs.