Though fish oils are rich in health-boosting properties, too much fish oil isn't really good for our body. Always remember that taking overly high dosages may only worsen your health. The most common side effects include constipation, loose stools, nausea, diarrhoea, heart burn, and abdominal pain. For the worst cases, one can also experience high blood sugar, acid reflux, low blood pressure, insomnia, stroke and increased risk of bleeding. These can happen if there’s an overdose on Omega-3 fatty acids. Some may also develop allergic reactions to any supplement, especially those who have fish or shellfish allergies. So you must consult with a specialist first and ask if you can take fish oil supplement. If you do, then ask about how much dosage is needed and when's the right time to take the supplement. Make sure to follow your doctor's recommendation and get more omega-3 nutrients from whole food sources instead of being purely reliant on supplements.