Does Berberine Lower Blood Sugar? What the Research Shows

Berberine has become a popular supplement for blood sugar control, but does berberine actually lower blood sugar?Research suggests it may modestly improve glucose levels and A1C in some people with type 2 diabetes, although the evidence is not strong enough to replace proven diabetes treatments.

My Experience With Berberine

I’ve personally taken berberine and noticed that my blood sugar seems easier to stabilize while using it. I treat that as my individual experience, not proof that berberine will have the same effect for everyone.

Blood sugar responses can vary based on diabetes type, medications, meals, activity, dose, and other factors. The clinical research discussed below provides a better picture of what berberine may—and may not—do for glucose control.

Key Takeaways

• Berberine may modestly reduce fasting and post-meal blood sugar.
• Research suggests it may also lower A1C in people with type 2 diabetes.
• Most of the evidence involves type 2 diabetes, not type 1 diabetes.
• Evidence for berberine for prediabetes is promising but still limited.
• Berberine can cause gastrointestinal side effects and interact with medications.
• Anyone taking insulin or glucose-lowering medication should discuss berberine with their healthcare provider first.

What Is Berberine?

Berberine is a naturally occurring plant compound found in plants including barberry, goldenseal, Oregon grape, goldthread, and tree turmeric.

It has a long history of use in traditional medicine and is now commonly sold as a dietary supplement for metabolic health.

Interest in berberine and blood sugar has increased because research suggests the compound may affect several pathways involved in glucose metabolism and insulin sensitivity.¹

How Much Can Berberine Lower Blood Sugar?

A systematic review and meta-analysis of 37 studies involving 3,048 people with type 2 diabetes found that berberine supplementation was associated with average reductions of approximately:

• 0.82 mmol/L (about 15 mg/dL) in fasting blood glucose
• 1.16 mmol/L (about 21 mg/dL) in 2-hour post-meal glucose
• 0.63 percentage points in A1C²

Those averages do not mean everyone taking berberine will experience the same change. If you’re tracking your own readings, our blood sugar charts can help you compare fasting and post-meal glucose ranges.

Study designs, doses, baseline glucose levels, other medications, and participant populations varied considerably. Much of the existing research has also been conducted in China.

For that reason, berberine should not be viewed as a guaranteed way to lower glucose.

Does Berberine Lower A1C?

It may.

A1C reflects average blood glucose over roughly the previous two to three months. Several clinical trials and meta-analyses have reported decreases in A1C among people with type 2 diabetes taking berberine.

The 37-study meta-analysis found an average reduction of approximately 0.63 percentage points in A1C.² If you want to see how an A1C value translates into estimated average glucose, use our A1C calculator.

That is potentially meaningful, but it does not establish berberine as an alternative to metformin, insulin, GLP-1 medications, or other established diabetes treatments.

How Does Berberine Affect Blood Sugar?

Researchers are still investigating exactly how berberine affects glucose metabolism.

Proposed mechanisms include:

• improving insulin sensitivity
• increasing glucose uptake by cells
• decreasing glucose production by the liver
• influencing carbohydrate metabolism
• affecting metabolic signaling pathways such as AMPK

These mechanisms are biologically interesting, but laboratory mechanisms alone do not prove that a supplement will produce meaningful clinical benefits.

Human trials remain more important.

Berberine for Prediabetes

Prediabetes is typically identified through fasting glucose, A1C, or glucose-tolerance testing. See our guide to normal blood sugar levels for the normal, prediabetes, and diabetes ranges.

Evidence for berberine for prediabetes is much more limited.

One small randomized, placebo-controlled trial followed 34 people with prediabetes for 12 weeks. Participants receiving berberine experienced improvements in fasting glucose, A1C, insulin resistance, and oral glucose tolerance compared with placebo.³

The results are encouraging, but a study involving only 34 participants is too small to establish that berberine prevents type 2 diabetes.

Lifestyle interventions—including nutrition, physical activity, weight management when appropriate, and regular glucose monitoring—remain the foundation of prediabetes management.

What About Berberine and Type 1 Diabetes?

Most human research on berberine and diabetes has involved people with type 2 diabetes.

There is not enough clinical evidence to recommend berberine as a glucose-lowering therapy for type 1 diabetes.

People with type 1 diabetes require insulin. Berberine should never be used to replace or reduce prescribed insulin without guidance from the diabetes care team.

The American Diabetes Association also notes that evidence is insufficient to routinely recommend herbal supplements to improve glycemia in people with diabetes.⁴

Can You Take Berberine With Metformin or Insulin?

This requires caution.

Combining berberine with insulin, metformin, sulfonylureas, or other glucose-lowering medications could potentially change blood glucose levels or increase the risk of unwanted effects.

Anyone using insulin or another glucose-lowering medication should also know the signs of low blood sugar.

Berberine may also interact with medications unrelated to diabetes.

Anyone taking prescription medication should discuss berberine with a physician or pharmacist before using it.¹

Berberine Side Effects

The most commonly reported berberine side effects involve the digestive system, including:

• nausea
• diarrhea
• constipation
• abdominal discomfort
• bloating

Berberine can also interact with certain medications.

It should not be used during pregnancy or breastfeeding and should not be given to infants because of concerns about bilirubin buildup.¹

Should You Take Berberine for Blood Sugar?

Berberine is one of the better-studied supplements for glucose control, but that does not make it a proven diabetes treatment.

Research suggests that it may modestly lower fasting glucose, post-meal glucose, and A1C in some people with type 2 diabetes. The evidence for prediabetes is much smaller, and evidence for type 1 diabetes is insufficient.

My own experience has been that my blood sugar appears easier to stabilize while taking berberine, but personal experience cannot predict how someone else will respond.

If you are considering berberine, especially while taking insulin or another glucose-lowering medication, discuss it with your healthcare provider first.

When to Call Your Doctor

Talk with your healthcare provider before starting berberine if you have diabetes and take insulin or other glucose-lowering medications.

Seek medical advice if you experience repeated low blood sugar readings, dizziness, weakness, severe digestive symptoms, or unexpected changes in glucose after starting any supplement.

Do not stop or reduce prescribed diabetes medication because your glucose readings improve without first discussing the change with your healthcare provider.

Frequently Asked Questions

References

1. National Center for Complementary and Integrative Health. “Diabetes and Dietary Supplements: What You Need To Know.” National Institutes of Health. [↩] [↩] [↩] [↩]
2. Xie W, Su F, Wang G, et al. “Glucose-lowering effect of berberine on type 2 diabetes: A systematic review and meta-analysis.” Frontiers in Pharmacology. 2022;13:1015045. doi: 10.3389/fphar.2022.1015045. [↩] [↩] [↩]
3. Panigrahi A, Mohanty S. “Efficacy and safety of HIMABERB® Berberine on glycemic control in patients with prediabetes: double-blind, placebo-controlled, and randomized pilot trial.” BMC Endocrine Disorders. 2023;23:190. doi: 10.1186/s12902-023-01442-y. [↩] [↩]
4. American Diabetes Association Professional Practice Committee for Diabetes. “5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes—2026.” Diabetes Care. 2026;49(Suppl. 1):S89–S131. doi: 10.2337/dc26-S005. [↩]