Does Cinnamon Interact With Metformin?

In our latest question and answer, our pharmacist discusses whether or not there is an interaction between metformin and cinnamon.


Can cinnamon interact with metformin?

Asked by Jonah On Mar 12, 2023

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Mar 13, 2023
Last updated Mar 13, 2023

Key points

  • Cinnamon has a mild antiglycemic effect, meaning it can lower blood sugar, which can theoretically interact with any drug that also lowers blood sugar, such as metformin.
  • However, both cinnamon and metformin are not associated with causing hypoglycemia, likely based on how they both work.
  • Multiple studies have evaluated the combined use of metformin and cinnamon, and the combination is generally reported to be well tolerated.
  • As always, it is important to tell your doctor about everything you are taking so you can be monitored appropriately.

Quick Answer

Cinnamon may have a mild antiglycemic effect (i.e., it can lower blood sugar), so there is a theoretical interaction with any drug that lowers blood sugar as well. However, both cinnamon and metformin are generally not associated with causing hypoglycemia (blood sugar that drops too low), so the risk of a serious interaction here is low.

Detailed Answer

The concern with combining both cinnamon and metformin is that they both have blood sugar-lowering effects, and taking them together could potentially lead to an additive effect (which would increase the risk of blood sugar dropping too low).

Metformin, one of the most commonly prescribed drugs for type II diabetes, lowers blood sugar in multiple ways, including:

  • Decreasing glucose production in the liver
  • Increasing insulin sensitivity, allowing the body to use insulin more effectively
  • Increasing glucose uptake into the muscles

Cinnamon is a spice that has been used for centuries in traditional medicine to lower blood sugar (among other things). In fact, it is one of the most commonly used ingredients in over-the-counter supplements marketed for supporting healthy blood sugar levels.

Studies show that cinnamon works in a similar way as metformin, increasing insulin sensitivity. This means that insulin can more effectively move glucose from the bloodstream into cells where it can be used for energy, which helps reduce blood glucose levels.

Hypoglycemia Risk?

The concern with combining multiple drugs that lower blood glucose is the risk of causing hypoglycemia, or blood glucose that drops too low. Hypoglycemia is associated with several symptoms, such as:

  • Sweating
  • Rapid heartbeat (tachycardia)
  • Anxiety or nervousness
  • Weakness or fatigue
  • Dizziness or lightheadedness
  • Headache
  • Blurred vision
  • Confusion

The risk of drugs causing hypoglycemia varies greatly depending on the specific one we are talking about. For example, drugs in a class of medications known as 'sulfonylureas' are very much associated with causing hypoglycemia, while another class, dipeptidyl peptidase 4 (DPP-4) inhibitors, are not.

Both metformin and cinnamon are generally not associated with having a great risk of causing hypoglycemia.

In fact, there have been quite a number of studies evaluating the combined effects of metformin and cinnamon and the side effect of hypoglycemia has not been reported.

There are a number of reasons why metformin and cinnamon don't have a high risk for causing hypoglycemia, even though they both lower blood sugar. These reasons include:

  • Cinnamon and metformin do not stimulate the pancreas to produce more insulin. Unlike some other diabetes medications (such as sulfonylureas), metformin does not directly stimulate the pancreas to produce more insulin. This means that it does not cause a sudden increase in insulin levels that can lead to hypoglycemia.
  • Cinnamon and metformin are thought to have a glucose-dependent mechanism of action, meaning they (for the most part) work when there is excess glucose in the bloodstream. Due to this, they generally do not lower blood sugar levels below 'normal' levels.

Overall, even though metformin and cinnamon have blood sugar-lowering effects, the risk of a serious interaction (i.e., their combined effects causing blood sugar to drop too low), is unlikely.

Final Words

Thanks so much for reaching out to us!

As with any medication or supplement, it's important to tell your doctor about everything you are taking, including cinnamon. Your doctor can help you determine the safest and most effective treatment plan for managing your blood sugar levels.

Please feel free to reach back out anytime.


  • A comparison of the effects of cinnamon, ginger, and metformin consumption on metabolic health, anthropometric indices, and sexual hormone levels in women with poly cystic ovary syndrome: A randomized double-blinded placebo-controlled clinical trial, PubMed
  • The Effect of Metformin and Cinnamon on Serum Anti-Mullerian Hormone in Women Having PCOS: A Double-Blind, Randomized, Controlled Trial, PubMed
  • Cinnamon use in type 2 diabetes: an updated systematic review and meta-analysis, PubMed
  • Efficacy of cinnamon in patients with type II diabetes mellitus: A randomized controlled clinical trial, PubMed

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at! You can also connect with Dr. Brian Staiger on LinkedIn.

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