The side effect of lemon grass includes itchiness, skin irritation, and rashes. However, the over-application of its extracts, such as lemongrass essential oil, and cosmetic products may also lead to severe effects. If you consume lemongrass tea or juice excessively, it may affect you during pregnancy, breastfeeding, and menstruation severely — consumption of lemongrass during chemotherapy risks in the hampering the effects of chemotherapeutic agents.