A person preparing to take an HbA1c test

Best Time for HbA1c Test: What to You Need to Know

Updated December 8, 2023. Written by Sendra Yang, PharmD, MBA. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

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If you don’t have diabetes, you may probably know someone who does. Diabetes is one of the most common chronic diseases in the United States. Over 37 million Americans have diabetes, and around 98 million have prediabetes.[1] With more people becoming overweight or obese, the number of diagnosed diabetes has more than doubled in the past 20 years. In the United States, diabetes is the eighth leading cause of death. A powerful test called the HbA1c, or A1c, can help identify prediabetes and diagnose diabetes.[2] Learn more about what the HbA1c is, the best time for HbA1c, and answers to other common questions regarding the test.

What Is the HbA1c Test?

HbA1c is also known as hemoglobin A1c, glycated hemoglobin, or A1c.[3] The HbA1c test is used to evaluate how well you are controlling your glucose or sugar levels. The test can also help diagnose diabetes. The HbA1c is reported as a percentage result and represents an average of your blood sugar levels over the past three months.

What Is Hemoglobin?

Hemoglobin is a protein that functions mainly to carry oxygen in red blood cells.[3] Hemoglobin bound to oxygen is what gives your blood its bright red color. Glucose in the bloodstream can become attached to hemoglobin; glycated hemoglobin is the medical term describing hemoglobin linked to glucose.

What Does the HbA1c Measure?

The HbA1c measures the average amount of glycated hemoglobin in your blood over a period of 3 months.[3] The lifespan of a red blood cell is around three months, and the test reflects the percentage of red blood cells with glucose-linked hemoglobin present at the time of the blood draw.[4] The more glucose you have in your bloodstream, the more glycated hemoglobin you will have, yielding a higher HbA1c result.

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When Is the Best Time for HbA1c?

The HbA1c test does not require you to fast before having your blood drawn.[5] Typically, tests that require you to fast are drawn in the mornings after not eating overnight and before you eat for the day. But you can take the HbA1c test at any time of the day.[4,5]

How often you should get the test and when can vary depending on whether you are testing to identify diabetes and prediabetes or managing the disease after your diagnosis.[5] If you have diabetes, get an HbA1c test at least two times a year and more often if there are changes to your medications. If you don’t currently have diabetes or prediabetes and are over 45 years of age, have risk factors, or have had gestational diabetes in the past, get the HbA1c test every three years. If you have prediabetes, speak with your healthcare provider about ways to improve your health and lower your risk of diabetes. Repeat your HbA1c every one to two years or as your healthcare provider recommends. If you don’t show symptoms of prediabetes or diabetes, but your result shows otherwise, get a second test done on a different day. Speak with your healthcare provider about how often you should get tested and the best time for HbA1c testing.

Everlywell makes it easy to re-test and check in on a variety of key biomarkers with the Everlywell+ monthly at-home lab testing membership. You have the option of testing your HbA1c levels as often as once a month, or you can switch between over 25 other home lab tests. Plus, you can save up to 48% off the regular price of tests as an Everlywell+ member. Enroll today to invest in your wellness year-round.

What to Expect During an HbA1c Test?

The HbA1c can be done in a lab through a traditional blood draw or with a finger stick.[6] It may take a few days to get the results back from a lab. During the blood collection process, you can expect the following[6]:

  • The healthcare provider will first locate your vein, a large blood vessel
  • Once the vein is located, the area will be disinfected, and a small needle will be inserted into the vein to collect the blood sample into a test tube
  • When an adequate amount of blood is drawn, the needle will be removed
  • A gauze and bandage will be placed over the site to stop the bleeding

If a finger stick was completed in your doctor’s office, you could get a result in about 5 minutes.[6] When getting a finger stick, you can expect the following [6]:

  • The healthcare provider will ask which finger you would like them to stick
  • Your finger will be disinfected
  • A tiny needle called a lancet will be used to prick your finger
  • Your fingertip will be lightly squeezed to form droplets of blood, which will be collected into a small, plastic container
  • Once enough blood is collected, you will be given gauze to stop the fingertip bleeding

HbA1c At-Home Lab Testing with Everlywell

At Everlywell, there is also an option for an HbA1c at-home lab test. When you receive your test kit, you can register it online. Then you can collect your sample from the comfort of your own home and mail it to a certified lab for testing. You will receive your results on a secure platform within a few days.

What Can Cause False High Blood Sugar Readings?

How Much Can I Lower My A1c in a Month?

What Happens When A1c Is Too High?


  1. Diabetes quick facts. Centers for Disease Control and Prevention. URL. Last reviewed April 4, 2023. Accessed July 21, 2023.
  2. Understanding A1C. American Diabetes Association. URL. Accessed July 21, 2023.
  3. Eyth E, Naik R. Hemoglobin A1C. [Updated 2023 Mar 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023. Available from: URL
  4. The A1C test & diabetes. National Institute of Diabetes and Digestive and Kidney Diseases. URL. Accessed July 21, 2023.
  5. All about your A1C. Centers for Disease Control and Prevention. URL. Last reviewed September 30, 2022. Accessed July 21, 2023.
  6. A1C: What it is, Test, Levels & Chart. Cleveland Clinic. URL. Accessed July 21, 2023.

Originally published August 9, 2023.

Sendra Yang is a professional pharmacist with nearly 10 years of experience. Sendra received her Doctor of Pharmacy and Master of Business Administration degrees from Wingate University School of Pharmacy. She is skilled in the pharmaceutical industry, pharmacy education, and clinical practice.

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