Does Medication Break Intermittent Fasting?

a woman is taking medicine with a glass of water, smiling, does medication break intermittent fasting
Melissa Mitri post Reviewer
The article is verified by Melissa Mitri
Registered Dietitian, Master of Science, Past President of CT Academy of Nutrition & Dietetics

Does medication break intermittent fasting? Can you take medication while fasting? Read on to find out the answers.

Table of Contents

Intermittent fasting (IF) is an eating schedule where you alternate between eating and fasting periods. It has gained in popularity due to its effectiveness in weight loss and the other health benefits it offers. 

We’ve talked in detail about what you can eat or drink while intermittent fasting before. In brief, you can have anything you like (in moderation, of course) during the eating window. 

There are restrictions as to what you can eat or drink during the fasting window, but what about medication? You may have a set schedule to stick to while taking medications, so it’s natural to be curious about how they might affect your IF regimen. 

Does medication break intermittent fasting? Can you take medications during your fasting window? Let’s dig deeper to find out.

Can You Take Medicine While Intermittent Fasting?

There is no short answer to this—it usually depends on which medications you take. 

In order to know if you can take medicine while intermittent fasting, you first need to understand how food has an effect on medications. Some pills are meant to be taken before meals, while some are to be taken with or after meals. 

Sometimes food can affect the way medications are absorbed into the system. For this reason, certain medications are best taken on an empty stomach. [1] Some foods may even interact with medications. The general advice is to take these medicines one hour before—or two hours after—a meal. 

At other times it is necessary to take medications with or immediately after a meal. [2] One reason for this is to reduce the possibility of side effects like nausea and vomiting. Some medications may even harm the stomach lining if taken on an empty stomach. Taking other medicines can cause symptoms such as heartburn and acid reflux if they’re not taken with food. 

If you want to make sure your medication will work properly and avoid unpleasant side effects, you need to strictly follow the instructions given by your doctor. Also, if you’re experiencing any discomfort after taking medications while intermittent fasting, it’s best to temporarily pause taking them and consult your doctor.

So, Does Taking Medication Break Intermittent Fasting?

According to the IF guidelines, anything that contains calories can break a fast. However, most medications are calorie-free, so you won’t break your fast if you take them during your fasting window. 

But that doesn’t mean you should take any medicine during the fasting period.

As the above paragraph explains, certain medicines should be ingested with food to avoid possible stomach damage or unwanted side effects. We will be elaborating on the types of medications that can be taken during the fasting window in a later part of this article.

At the same time, you should keep in mind that some medications and supplements can contain calories in them. Examples include sugar-added syrups, gummies with gelatin or starch, or pills with a sugar coating. They will introduce calories into your system, thus breaking your fast. 

Moreover, supplement gummies and syrups contain various flavors and sugar, and they can trigger hunger pangs. This can lead to impromptu eating despite it being the fasting window.

Medications And Intermittent Fasting: Effects And Effectiveness

As we explained early in the article, some medications work best when taken on an empty stomach, while others need to be taken with food. 

Let’s see how some common medications perform during intermittent fasting and what the best time to take them is. The medications mentioned here won’t break your fast, but some may be absorbed better if taken concurrently with certain foods.

Supplements

There are no strict rules regarding when to take most supplements, but some work best when taken under certain conditions. For example, some absorb best when combined with certain food groups, and some are better ingested with meals to minimize side effects like nausea. 

  • The fat-soluble vitamins A, D, E, and K should be taken with a fat-containing meal. By definition, they dissolve in fat, so you need a fatty substance for them to get absorbed into the blood. [3] This means you should take them within your eating window for them to be most effective. 
  • Water-soluble vitamins like vitamin C can be absorbed with water, so there are no restrictions as to when to take them. However, in rare cases, ascorbic acid (vitamin C) can increase stomach acidity, so if you’re prone to acid reflux, it might be best to take it with food. [4]
  • Iron supplements are usually recommended to be taken on an empty stomach to increase absorption, but they can cause side effects in some people. [5] If you get symptoms like upset stomach or nausea after taking iron supplements, it’s best to take them during your eating window or immediately after.

Painkillers

Painkillers like paracetamol can be taken with food or without it, so it doesn’t matter whether you take it within your eating or fasting window. [6]

However, opinion is divided on NSAID (non-steroidal anti-inflammatory drugs) painkillers such as ibuprofen, diclofenac, and aspirin. 

While the popular belief is you should take these medications with food to avoid stomach upset, scientific evidence says otherwise. It is proven that taking these painkillers with food can decrease their bioavailability and overall effectiveness [7].

In that case, you can take them either within the eating window or the fasting window if you allow a few hours between meals and medication. 

Antidiabetic Medications

Diabetes medications act to lower your blood sugar levels, so it’s not a good idea to take them during a fast. Your blood sugar levels can dip too low if you take these medications during your fasting window, pushing you into a hypoglycemic state. [8] 

This can cause symptoms like dizziness or shaking, or it can even result in serious conditions like diabetic coma. [9] [10]

Blood Pressure Medications

Intermittent fasting is known to reduce blood pressure, so you should avoid taking medications that lower blood pressure during the fasting period [11]. You can take them during the eating period to avoid drastically lowering your blood pressure. 

You might also want to consult your doctor about reducing the dosage if your blood pressure stays low persistently.

Thyroid Medications

Thyroid medications are best absorbed when taken during a fast, according to several studies. Fasting can significantly affect thyroid function, but the exact outcomes may differ depending on the individual. [12] While some people might need their dose and the type of medication adjusted accordingly, most can continue their medications without issue.

Antibiotics

The best time to take an antibiotic mostly depends on the type. Some antibiotics are prescribed to be taken with or after meals, as they can disrupt the gut lining if taken in a fasting state. Others can be affected by certain foods, so they are best taken before meals. [13]

The best action plan is to follow the directions on the package when taking antibiotics. 

However, it’s possible that you may have to take them during both your eating and fasting windows as antibiotic dosages are usually spaced at hourly intervals. 

Antidepressants

Antidepressants can trigger side effects such as nausea. In those instances, you may be advised to take these medications with food to mitigate the symptoms. [14] 

Another aspect you should be aware of while taking antidepressants is that they can increase your appetite and also cause you to gain weight [15] [16]. While this might work against the purpose of intermittent fasting, you should never stop taking them without discussing it with your doctor first. 

You can make conscious food choices during your eating window to control increased food cravings, like reaching for high-fiber foods instead of high-sugar foods. You can also get help from a nutritionist to deal with increased appetite. 

What If I Have An Extended Fasting Window?

Some people follow prolonged fasting regimens such as alternate-day fasting or One Meal a Day (OMAD). If this is you, you need to heed caution when taking medications.

If you’re on long-term medication such as antidiabetic or blood pressure medicine, always discuss with your doctor the best medication schedules that suit your fasting routine.

For short-term medication doses that fall within the fasting period, you can consume certain foods that don’t necessarily break a fast if taken in small amounts. They include chia or flax seeds, MCT oil, and bone broth. We know that technically any food or drink will break a fast, but the effect of these foods, when taken in small amounts, can be negligible.

Final Words

Wrapping up, here are the key takeaways of this article:

  • Does medication break intermittent fasting? No, unless it contains caloric substances like sugar or starch.
  • Is it permissible to take medicine while intermittent fasting? Absolutely. However, when you should take your medicine depends on the type of medication. Some medicine can be taken with meals, while some is best taken on an empty stomach. Talk to your doctor about how you should take your medications.
  • What should I do if I’m practicing longer fasting durations? Talk to your nutritionist and take appropriate measures to mitigate the effect of medication on the stomach.

We hope you now have a better idea of how to integrate medications into your IF schedule. You can try our all-in-one weight-loss app to keep up with your intermittent fasting schedule and track the caloric and nutritional value of your meals.


The information provided on the site is for educational & informational purposes only. If you seek diagnosis, treatment, or medical advice or want to make significant changes in your diet and health-related routine, please, consult a medical professional or healthcare provider.

You may also like