Taking a fish oil supplement is no different than just eating fish. However, fish does have contaminants (the most popular and well known being mercury) that can also be present in fish oil unless it was purified. It is especially important to avoid big fish such as sharks, sword fish or other fish that consume their smaller cousins. These big fish live a long time while eating small fish and end up accumulating large concentrations of mercury in their bodies. This is by far the biggest of all possible fish oil side effects so in some ways fish oil supplements are a good way to get the omega 3 you absolutely need while avoiding some of the dangers of certain types of fish AS LONG as your fish oil was purified. Basically what this means is that you should put some research into finding the best fish oil supplement and maybe be willing to pay more for your fish oil to be sure its purified/refined so it doesn’t have mercury and other contaminants in it. Or you can opt to eat smaller fish such as salmon or sardines which have a much lower risk.
So, for the average healthy person, it’s completely safe. Of course, if you are pregnant, allergic to fish, or already have any kind of known health issues, you should check with your doctor first just to be safe. While omega 3 is recommended for pregnancy the source of it needs to be especially clean. This is kind of a paradox because while you do not want to take fish oil that might give your baby mercury, which can produce birth defects, you definitely need to take some omega 3 if you want to ensure proper brain development, just make sure to avoid the omega 3 fish oil side effects when taking them! during pregnancy, or if you simply do not trust fish oil you might want to try out krill oil supplements.
Also with fish oil you do not risk taking “too much” of it. Some studies had people take up to 8 grams of it with no changes from those who would only take pills of 1 gram ( which is a normal daily supplement size). As a side note, fish oil does “consume” some of the vitamin E in your blood so some supplements come with added vitamin E. If yours does not and you really love eating fish or taking fish oil supplements just make sure you have some vitamin E foods in your diet ( you don’t need a lot so don’t overstress yourself over this but we are talking about possible fish oil side effects here).
Finally some people experience a “fishy” taste side effect in their mouth. If this is the case for you and it bothers you, try another brand. Or you can try krill oil supplements which also contains omega 3 and are based off Krill instead of “oily fish”. Krill oil has the benefit of not being as criticized as fish is for the pollutants it contains as well as avoiding the “fishy” taste as previously mentioned.
If you heard about possible vitamin a toxicity side effects related to fish oil this is more one of the cod liver oil side effects if it’s taken in large quantities and not really a side effect of fish oil specifically.
Make sure to put some research behind the brand of fish oil your hoping to buy to avoid heavy metals which is once again the biggest of all fish oil side effects you want to avoid! You might also want to contact your health doctor for his approval or if he has any recommendation. If you find looking for the best fish oil supplement is too much effort you might want to look into some of the flax seeds benefit which are quite similar as they also contain a form of omega 3 however one of the flax seed oil side effects or rather… limitation is that your body has limited quantities (higher in women) that it can convert of flax seed into omega 3 each day.