I keep hearing that prescription Rx doesn’t break your metabolic (not caloric) fast, but literally everything else except water will. Why is this? Do fasting gurus say this to avoid legal responsibility of someone not taking their pills to avoid breaking their fast or is there science behind it?
Prescriptions are designed to deliver medicine and nothing else. The non-medicinal ingredients are typically things that break down in the digestive system but aren’t absorbed.
Some tablets are covered in a sugar coating but the amount is so low, we don’t know if it registers.
In regards to the medicine itself, there’s are so many things prescribed that an ethical medical professional is going to say ‘talk to your own doctor or pharmacist.’ Which is why that sort of warning or addendum pops up in all the various youtube videos or articles you might read.
Your meds will not break your fast unless they contain something that will be broken down into glucose. Ingesting anything that does not get broken down into glucose will not break a fast metabolically. Water, tea, and black coffee are all completely safe. Carbs are pretty much completely out. Fat is somewhat on the safer side as most of it doesn’t get broken down into glucose. Protein is in the middle. There are people who can do entire fat based diets that never raise their blood glucose high enough to break their fast.
What breaks a fast usually comes down to that individual person as well as their current metabolic state. If you’ve recently entered a fasting state it is possible that one peanut could break your fast. If you’ve been fasting for a while you could eat an entire handful of peanuts and potentially not break your fast.
The only way to know for sure is to wear a continuous blood glucose monitor and work with a doctor to know what number is the tipping point between the two metabolic states.