Can I Take Medications Before a Fasting Blood Test?

Can I Take Medications Before a Fasting Blood Test – Overview

If you have been advised to undergo a fasting blood test by your healthcare provider, you must avoid eating or drinking anything (except water) for several hours before the blood test.

Normally, when you eat and drink, food and beverages are absorbed into your bloodstream. This may affect the results of certain types of blood tests.

When Is Fasting Required Before a Blood Test

Can I Take Medications Before a Fasting Blood Test

When Is Fasting Required Before a Blood Test?

The most commonly performed blood tests that need you to fast are:

Glucose Test

The glucose test is used to measure blood sugar levels. A glucose tolerance test is a type of blood test that requires you to fast for at least 8 hours before the test.

Once you arrive at the healthcare facility or testing lab, you will have your blood tested, made to drink a special liquid containing glucose and have another blood test done once an hour, then two hours and maybe a third time after another hour, if needed.

Glucose tests are important in diagnosing diabetes.

Lipid Test

Lipid tests are used to measure triglycerides. This type of fat is often found in the bloodstream, along with cholesterol, the fatty, waxy substance found in the blood and every cell of the body. High triglycerides and LDL cholesterol levels can put you at risk of heart disease.

How Long Do You Need to Fast Before a Fasting Blood Test

Usually, doctors advise patients to fast for at least 8 to 12 hours before a test. Most tests that need fasting are normally scheduled for the morning. This way, most of the fasting time is overnight.

What Can You Drink Besides Water Before a Fasting Blood Test

You cannot drink coffee, soda or juices and other beverages before a fasting blood test because these can enter your bloodstream and affect the blood test results. Besides this, you should avoid chewing gum, exercising or smoking before a fasting blood test to ensure accurate results.

However, drinking water is acceptable before a fasting blood test, and doctors actually advise it. This is because water helps to add more fluid to your bloodstream, which makes it easier to draw blood for the test.

Can I Take Medication Before a Fasting Blood Test

You will need to consult with your healthcare provider regarding this. Usually, it is OK to take your regular medications. However, certain medications are not advised to be taken before a fasting blood test, especially those medicines that need to be taken with food.

What if You Mistakenly Eat or Drink Anything Before a Fasting Blood Test

If this happens, make sure to tell your healthcare provider. Usually, your healthcare provider will reschedule the fasting blood test for a later date when you can complete your fast.

When Can I Eat and Drink After a Fasting Blood Test

Once your test is complete, you can eat and drink normally. You may want to bring a snack so you don’t need to stay hungry for long once the blood test is completed.


Discuss every query or doubt with your healthcare provider before scheduling the fasting blood test. You should consult your healthcare provider before taking any lab test. Most tests do not require fasting or any other special preparations.

For others, you may be advised to avoid certain foods or drinks, medications, and even activities. You are taking the right precautions before a blood test will ensure an accurate result and the best diagnosis.

See Also

What is the Most Popular Medication for High Blood Pressure

What Medications Disqualify You From Donating Blood

Integrative Medicine Training for Physicians

How to Educate Patients About Medications

Do Blood Thinners Decrease Blood Pressure

Current Version
December 17, 2022
Updated By
Franco Cuevas, MD
October 30, 2022
Written By
Shubham Grover

Follow us