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What happens if you stop taking diabetes medication?

Medically reviewed by Sally Chao, MD. Last updated on Jan 9, 2024.

Official answer


If you stop taking a diabetes medication without consulting your doctor first, your blood sugar will likely return to abnormally high levels. Uncontrolled high blood sugar can lead to serious health consequences over the long term, including:

To avoid the risks associated with uncontrolled high blood sugar, you should talk to your doctor before discontinuing any diabetes medications. To keep your blood sugar in check, it’s necessary to take your diabetes medication exactly as prescribed.

If your diabetes medication isn’t working as you’d hoped or you’re experiencing unpleasant side effects, your doctor may be able to remedy these problems by altering the dose, prescribing a different drug or recommending lifestyle changes. For example, long-term use of the diabetes drug metformin can sometimes lead to vitamin B12 deficiency. Your doctor may suggest taking B12 supplements to counteract the deficit if this occurs, along with continuing your diabetes medication.

In rare cases, your doctor may advise you to discontinue a certain diabetes medicine. For example, you may need to stop taking metformin if your kidneys are not functioning properly. Having poor kidney function and taking metformin may increase the risk of a life-threatening complication called lactic acidosis. Symptoms of lactic acidosis include:

  • Extreme fatigue or weakness
  • Stomach problems (nausea, vomiting, pain)
  • Poor appetite
  • Difficult or rapid breathing
  • Changes in heartbeat

If you experience these or other severe side effects while taking diabetes medications, contact your doctor immediately.

Related Questions

  1. Guerci B, Chanan N, Kaur S, et al. Lack of Treatment Persistence and Treatment Nonadherence as Barriers to Glycaemic Control in Patients with Type 2 Diabetes. Diabetes Ther. 2019;10(2):437-449.
  2. Centers for Disease Control and Prevention (CDC). Diabetes: What is Diabetes? November 16, 2021. Available at: [Accessed January 4, 2022].
  3. U.S. National Library of Medicine MedlinePlus. Metformin. March 15, 2020. Available at: [Accessed January 4, 2022].
  4. National Health Service (NHS). Metformin. February 8, 2019. Available at: [Accessed January 4, 2022].
  5. Polonsky WH, Henry RR. Poor medication adherence in type 2 diabetes: recognizing the scope of the problem and its key contributors. Patient Prefer Adherence. 2016;10:1299-1307.

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