Do Fish Oil Supplements Affect Your Sleep?

Our bodies are incredibly sensitive when it comes to sleep. Ruminating thoughts, a too-hot room, or spending an hour before bed exposing your eyes to blue light while scrolling through your phone can all negatively impact our ability to get a good night's rest.

It's no secret that certain food or drink items can also affect our quality of sleep, such as having a cup of coffee too late in the day. On the other hand, some foods or beverages may benefit our sleep, such as a soothing chamomile tea in the evening time. This may also be the case with certain supplements, including melatonin, GABA, magnesium, or passionflower, according to the Sleep Foundation.

Containing omega-3 fatty acids, fish oil is another supplement commonly used for a variety of reasons. For example, some studies show a link between fish oil supplementation and decreases in high blood pressure, as well as improvement in arthritis-related joint pain or stiffness (via Mayo Clinic). However, fish oil supplements may pose both potential benefits and drawbacks when it comes to sleep.

Some research shows that fish oil supplements may have value to offer when it comes to sleep. In a 2021 study published in Nutrients that was conducted over the course of 26 weeks, researchers gave 84 participants who did not eat oily fish on a regular basis either a placebo or omega-3 polyunsaturated fatty acids. Participants were between the ages of 25 and 49.

For those who received the omega-3 supplements, researchers took a closer look at the differences between DHA-rich oil and EPA-rich oil and their effects on participant sleep. The research findings revealed that those who took the DHA-rich supplements experienced greater sleep efficiency and fell asleep faster than those in the placebo group.

That said, those in the DHA-rich oil supplement group said they felt less rested than those in the placebo group. When compared to those who were given EPA-rich oil, the DHA group also reported feeling lower in energy and less ready to perform. Based on these findings, is it possible that fish oil could also potentially negatively affect our sleep too?

Findings from a 2015 case study published in Oxford Medical Case Reports revealed a possible connection between fish oil supplementation and insomnia. A male in his 50s who was taking a high-EPA fish oil supplement for several months as part of his comprehensive treatment plan for depression told his doctor that he had been experiencing general anxiety, panic attacks, and awakening in the middle of the night with excessive worry and shortness of breath.

Upon ceasing use of the supplements, the patient's symptoms of insomnia and anxiety subsided, only to return again weeks later when the patient began taking the same dose for a period of two days. Since stopping supplementation completely, the patient has not experienced any recurrence of anxiety or insomnia.

Because the research around fish oil supplements and their effects on sleep are still somewhat mixed, it's possible that some people may find supplementation helpful, while others may not. If you are interested in giving fish oil supplementation a trial run, be sure to consult with your doctor beforehand. While considered safe for use, the Mayo Clinic reports that fish oil can have potential drug interactions and side effects such as heartburn, nausea, diarrhea, rash, sour breath, or a fishy aftertaste left in the mouth.