Smoking & Vaping During Fasting Does It Break Your Fast?, Smoking and vaping are not only harmful but also invalidate your fast during Ramadan. Fasting is a time for spiritual purificationlets Ramadan: Is it permissible to smoke electronic cigarettes while fasting? Can you vape during Ramadan? If smoking breaks your fast, explained Fasting for Blood Work: What You Need to Know Before Your Test Religious scholars and doctors reject misconceptions relating to vaping while fasting during Ramadan.