The side effects of fishoil are mainly reflected in two points: the first point is allergic reaction. The second point is the damage to the kidneys. Specifically, fishy grass, whether taken orally or as an injection, has the potential to cause allergies, drug-induced dermatitis, peripheral neuritis, and even anaphylactic purpura and anaphylaxis. If the treatment is not timely, it can also cause life-threatening. In addition, fishy grass also contains a certain degree of toxicity, itself contains aristolochia lactam, this substance for a long time application, will cause irreversible damage to the kidneys, so that the kidney function decreases, creatinine and urea nitrogen rises. Therefore, fishoil is not suitable for long-term application, either orally or by injection.