Diarrhea

Fish oil is packed with essential nutrients, but it can still pose a risk when excessively consumed. One of the most common side effects related to fish oil consumption is diarrhea, which may be more likely when taking high doses. In fact, along with other digestive issues including gas, one research found that diarrhea is one of the most common side effects of fish oil.

Other types of omega-3 supplements may also result in diarrhea, in addition to fish oil. For instance, flaxseed oil, a popular vegetarian substitute for fish oil, has been found to have a laxative effect and may increase the frequency of bowel movements. Make sure you take your supplements with meals and think about reducing your dosage if you have diarrhea after taking omega-3 fatty acids.