10 Best Herbs and Supplements for Diabetes That May Help

Diet, lifestyle, and prescribed medications are cornerstones of managing type 2 diabetes. Herbs and supplements can also enhance blood sugar control. Learn about well-researched dietary supplements to discuss with your healthcare provider.

Sarah Bullard, MS, RD, LD
— Signos
Dietitian and Nutrition Writer
Green checkmark surrounded by green circle.

Updated by

Green checkmark surrounded by green circle.

Science-based and reviewed

July 19, 2024
November 14, 2023
— Updated:

Table of Contents

Healthcare professionals recommend starting with the big picture when managing type 2 diabetes. 

With type 2 diabetes, carbohydrate digestion is altered, leading to elevated blood glucose (or blood sugar) levels. Insulin helps to bring blood sugar levels within range. Keeping blood sugar levels within a target range is vital for managing diabetes and preventing diabetes complications.1 

Two “big picture” factors for keeping blood sugars within range are eating a balanced diet and incorporating physical activity. If those changes are ineffective in balancing blood sugar levels, your healthcare provider may recommend different medications.

Individuals trying to manage blood sugar levels often look to dietary herbs and supplements for further assistance and a more natural solution. 

Unlike prescription medications, the US Food and Drug Administration (FDA) oversees dietary supplements less stringently. Laws dictate that dietary supplements are not intended to diagnose, treat, prevent, or cure any disease. However, supplement makers can claim that a product helps maintain healthy blood sugar levels.2

Product labels and manufacturer claims can be confusing to consumers. Potential interactions and side effects can occur if you use any diabetes medication with dietary herbs and supplements, so always consult your healthcare provider before doing so. 

In this article, you’ll learn about supplements, vitamins, and herbs and their ability to help people living with type 2 diabetes control their blood sugar and potential side effects.


What are Diabetic Supplements?

The Dietary Supplement Health and Education Act (DSHEA) of 1994 defines dietary supplements as products taken by mouth with dietary ingredients intended to supplement a diet. 

Dietary ingredients include vitamins, minerals, herbs, spices, amino acids, botanicals, enzymes, and metabolites. They can be in tablet, capsule, soft gel, liquid, powder, and bar form. 

Since they are not considered drugs, the FDA does not require strict regulation. The FDA does require a supplement facts panel detailing each ingredient within the supplement.3 

6 Supplements for Diabetes



Chromium is a mineral needed for glucose metabolism and works by enhancing insulin. Chromium picolinate is well studied but has mixed results in human and animal studies. 

One study highlighted an association between chromium deficiency and high blood sugar levels, indicating a need for supplementation. Extensive studies have shown a small effect of chromium supplementation on improved blood sugar and insulin levels among people with and without diabetes.2,3  

Excessive intake of chromium can cause kidney and liver failure. Chromium supplements can interact with many medications, so consult your healthcare provider before adding chromium supplements to your routine.


Selenium is an antioxidant mineral that helps protect the pancreas. The pancreas makes insulin, which is a critical hormone needed for managing blood sugar levels properly.4 

Researchers reviewed the use of supplements in people living with diabetes, and a review revealed 25 studies on selenium with mostly positive results. However, two meta-analysis studies found no improvement in the risk of developing diabetes with selenium supplementation.3 

Human clinical trials found health benefits associated with selenium supplementation, such as improved blood sugar, insulin, insulin resistance, blood lipids, and markers of inflammation.3,4 


Zinc aids in insulin production and action within the cells, reduces inflammation, and further protects the pancreas and insulin.5 

Zinc supplementation was found to have positive effects in 30 studies. Three meta-analyses found improved fasting blood sugar and insulin levels. Another study found improvements in markers of diabetic kidney injury. In individuals with prediabetes, progression to type 2 diabetes is slowed or reduced.3,4   

Zinc supplements are usually well tolerated if they are taken within a safe dosage level. Consult your doctor about the correct dose for you before starting a zinc supplement. 


Magnesium aids in insulin action or helps improve insulin sensitivity. If your magnesium levels are low, insulin may also not work well within your body, leading to elevated blood sugar levels. Magnesium is also thought to have a protective role in developing type 2 diabetes.5 

Large prospective studies with more than 1 million participants found that dietary magnesium supplements are associated with a 19% reduction in risk of type 2 diabetes. 

Researchers have compared blood sugar levels between the participants taking magnesium supplements and those not receiving magnesium. Those taking magnesium had improved blood sugar levels, blood lipids, blood pressure, and improved heart disease.

Magnesium supplementation has minimal safety issues. Higher doses can lead to an increased risk of diarrhea. 

Probiotics and Prebiotics

Probiotics and prebiotics can improve the body's response to insulin by modifying the number and quality of gut bacteria. Fructans act as non-digestible prebiotics, and bacteria in the large intestine ferment the prebiotics and positively change gut bacteria. Inulin, resistant starches, cellulose, hemicellulose, pectin, and gums are also prebiotics.5 

Studies on 2,086 adults living with diabetes and using prebiotics and probiotics found that participants experienced reduced fasting blood sugars and cholesterol levels.5 


Cinnamon, curcumin, berberine, citrus flavonoids, quercetin, garlic, red yeast rice, and neem extracts all have shown some ability to improve insulin response in the body.  However, the studies are usually small or have mixed results.5

One meta-analysis of 16 randomized controlled studies found that cinnamon reduced fasting blood glucose levels and improved insulin response compared to individuals not taking cinnamon.6 

Overall, researchers recommend cinnamon inclusion in a treatment plan but never to replace medications.

5 Herbs for Diabetes



As mentioned above, berberine can improve insulin response (insulin sensitivity).5 Berberine comes from a variety of plants. 

Thirty-seven studies with 3,048 patients were included in a meta-analysis of randomized controlled trials and showed berberine could reduce fasting blood sugar levels and HbA1c (average blood sugar level for the past three months).7 

Taking berberine with diabetes medications did not increase side effects or increase the risk of low blood sugar levels in most studies.7 However, berberine may interact with other medications.

Bitter Melon

Bitter melon is a green fruit found in tropical climates. Bitter melon fruit and seeds act similarly to insulin, helping to reduce blood sugar levels in the body. 

A meta-analysis involving ten studies with 1,045 participants found that bitter melon reduced fasting and after-meal blood glucose levels and HbA1c. 

The study's authors stated the evidence needed to be of higher quality overall due to the small sample size and the need for more data on safety. Animal studies find the plant may cause miscarriages and decrease fertility.8 

Milk Thistle

Milk thistle is a member of the aster family, which includes daisies and thistles. The plant is edible. 

It is not fully understood how milk thistle lowers blood sugar levels. Components in milk thistle called silymarin improve insulin response and protect the pancreas.

In 2020, a meta-analysis of 16 studies involving 1,358 participants found that milk thistle users had reduced fasting blood sugar levels and HbA1c compared to the control group.

Additionally, a combination of berberine and milk thistle was more effective than either substance alone at reducing HbA1C in people living with type 2 diabetes. 

Milk thistle is usually well tolerated, but those with daisy or ragweed allergy may experience an allergic reaction or other symptoms.8 

Green Tea

Unsweetened green tea is an abundant source of polyphenols (100mg in one cup), a type of antioxidant.

Observational studies consistently associate green tea or coffee intake with a lower risk of type 2 diabetes. Green tea intake is also associated with improved insulin response. 
A study of over 17,000 Japanese adults found that people who drank at least six cups of green tea daily had a 33% reduced risk of type 2 diabetes.  

Other randomized controlled trials involving participants drinking green tea have not shown improved blood sugar or insulin levels. However, consuming green tea extract powder has lowered fasting blood sugar levels. 

It is unclear whether green tea can significantly lower blood sugar levels.9 

Frequently Asked Questions

Should I Take Herbs and Supplements to Manage My Diabetes?

Diet, lifestyle changes, exercise, and prescribed medications are cornerstones of managing type 2 diabetes. Herbs and supplements can also enhance blood sugar control. However, always consult with your healthcare provider before starting dietary supplements, especially if you are on existing medications such as metformin.

What Are Some Over-The-Counter Options for People With Diabetes?

In addition to diet, exercise, and prescription medications, over-the-counter herbs and supplements can help improve blood sugar control and be a part of a diabetes management plan. Several supplements are available, such as chromium, selenium, zinc, magnesium, probiotics/prebiotics, and cinnamon. Herbs that can be used to improve blood sugar control include berberine, bitter melon, milk thistle, and green tea. 

What Are the Best Supplements for Type 2 Diabetes?

Supplements with the most supporting evidence and/or limited side effects and interactions are chromium, zinc, magnesium, cinnamon, milk thistle, green tea, probiotics, prebiotics, and berberine.

Learn More About How Blood Sugar Levels Work with Signos’ Expert Advice

A Signos’ continuous glucose monitor (CGM) can help you monitor your blood sugar level as it responds to vitamins and supplements, food, beverages, and exercise.  

A Signos CGM can help you improve your health without medication or enhance your results when taking diabetes medication. Learn more about the importance of managing blood sugar levels on Signos’ blog. Then, take a quick quiz to determine if Signos fits your needs.

Get more information about weight loss, glucose monitors, and living a healthier life
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
  • Item 1
  • Item 2
  • item 3
Get more information about weight loss, glucose monitors, and living a healthier life
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

Topics discussed in this article:


About the author

Sarah Bullard is a registered dietitian and nutrition writer with a master’s degree in nutrition. She has a background in research and clinical nutrition, personalized nutrition counseling, and nutrition education.

View Author Bio

Please note: The Signos team is committed to sharing insightful and actionable health articles that are backed by scientific research, supported by expert reviews, and vetted by experienced health editors. The Signos blog is not intended to diagnose, treat, cure or prevent any disease. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider. Read more about our editorial process and content philosophy here.

Interested in learning more about metabolic health and weight management?

Try Signos.