In general, a fast is broken when you swallow something and it enters the stomach or gives the body nutrition. Medicine taken into the body that does not enter the stomach is permissible. Injections Intravenous and intramuscular injections do not break a fast. Injections that administer medicine or vaccinations into the body, whether intravenous (through the veins) or intramuscular (through the muscles) do not break the fast. They do not directly enter the stomach. A fast is invalidated if you use a drip, as you are receiving hydration and if you need a drip then you are sick and should not be fasting. Part of fasting is experiencing weakness and hunger. If one is pepping up one’s system by injecting supplements like vitamin C, this would not be permissible. Dental work You can have an anaesthetic injection while fasting, but be careful not to swallow anything during the dental work for instance from the water spray. If you swallow it, your fast will be invalidated. Contrast dye Contrast dye injected through vein, for instance for an MRI, Xray, CT scan or ultrasound, or inserted via the rectum through a tube do not invalidate a fast. Contrast dyes ingested by mouth would invalidate a fast. Blood test Having a blood test does not invalidate a fast, as it is merely the taking out of blood. It is only disliked if it could weaken one from being able to fast. Inhalers In general the use of oral medication invalidates a fast. Inhalers are taken by mouth, are meant to direct medicine into the lungs not the stomach. There is a difference of opinion among scholars whether a substance entering the lungs would invalidate the fast or not. If you follow the opinion that a substance entering the lungs does not invalidate the fast, … Continue reading Will an injection, contrast dye, drip or using an inhaler break my fast?