Insomnia
According to some research, taking fish oil in small doses may improve the quality of your sleep. For instance, one research involving 395 children found that taking 600 mg of omega-3 fatty acids every day for 16 weeks improved the quality of their sleep. However, in some cases, taking too much fish oil may actually disrupt sleep and cause insomnia.
According to one case study, a patient with a history of depression's insomnia and anxiety symptoms got worse after taking a high dose of fish oil. However, current research is limited to case studies and anecdotal reports. To further understand how high dosages could impact the general people's sleep quality, more study is required. If you experience insomnia, try taking the fish oil earlier during the day, and start out at lower dosages and increase it slowly.