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?
Mar 12, 2023- Cinnamon and metformin both lower blood sugar, but the risk of a serious interaction is low because neither medication typically causes dangerously low blood sugar on its own.
- Studies combining metformin and cinnamon have not reported cases of blood sugar dropping too low, even though both work to improve how the body uses insulin.
- It's important to tell your doctor about any cinnamon supplements you're taking so they can monitor your blood sugar management plan.
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.
References & sources
- 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
Glossary — Terms in This Answer
- Antiglycemic effect
- The ability to lower blood sugar levels.
- Hypoglycemia
- A condition where blood sugar drops too low, causing symptoms like shakiness, sweating, and confusion.
- Additive effect
- When two substances combine to create a stronger effect than either would produce alone.
- Insulin sensitivity
- The body's ability to respond effectively to insulin and use it to move glucose out of the bloodstream.
- Glucose uptake
- The process by which cells absorb glucose from the blood.
- Sulfonylureas
- A class of diabetes medications that work by stimulating the pancreas to produce more insulin.
- DPP-4 inhibitors
- A class of diabetes medications that help the body use insulin more effectively without causing dangerously low blood sugar.
- Glucose-dependent mechanism of action
- A way of working that primarily affects the body only when there is excess glucose in the bloodstream.