Across 3,026 first-hand reports, people mentioned a side effect 39 times (about 1 per 100 reports). The most common: fish burps, stomach issues, vivid dreams. User reports show what people notice — they can't tell you whether Omega-3 is safe for you.
“I started high EPA fish oil daily, definitely think it made some kind of difference.”
“I’ve tried physical therapy, swimming, exercises, omega-3, turmeric, and other anti-inflammatory stuff—nothing seems to help.”
“I take high quality fish oil supplements and eat a lot of fish too. I recently began drinking pure beet juice and that seems to have helped more than anything.”
“I added fish oil...my head feels cloudy...Yes I have. 2g a day. It got better, I'm about a month in myself.”
Conclusion: All studies had a high risk of bias and the evidence was very low. The main conclusion is that anti-inflammatory diets resulted in significantly lower pain than ordinary diets (-9.22 mm; 95% CI -14.15 to -4.29; p = 0.0002; 7 RCTs, 326 participants).