Fasting for a blood test typically involves abstaining from food and sometimes drinks for a certain period of time before the test. This is important because eating or drinking can affect the Glutathione Benefits: Top Uses for Your Health Nutrisense Journal Lists of Blood Tests That Require Fasting Protocol for measuring erythrocyte glutathione reductase activity coefficient to assess riboflavin status ScienceDirect How to prepare for a fasting blood test: what you can and cannot do HealthcareOnTime Blood Tests (Requires Fasting)