How Long Does it Take for Berberine to Lower Blood Sugar?

Managing blood glucose (sugar) is the most important part of diabetes management to enhance insulin sensitivity. It’s also important for people with insulin resistance or conditions associated with it, such as fatty liver disease metabolic syndrome, and polycystic ovary syndrome.

Lifestyle modifications such as eating healthy and exercising are the cornerstones for keeping blood glucose in a healthy range. Along with these modifications, supplementing with certain ingredients such as berberine may have an additive effect for maintaining healthy blood glucose levels.

However, you may wonder what berberine is and how long it takes to experience its purported blood glucose-lowering effects.

This article provides an evidence-based overview of berberine, discussing how long it takes to lower blood glucose levels and how it stacks up against common diabetes drugs.

What is Berberine?

Berberine is a compound derived from the roots and bark of many plant species, but Berberis, commonly known as barberry, is its primary natural source. It has long been used in Chinese and Ayurvedic medicine to treat infections, indigestion, skin disorders, and diabetes.

Today, berberine is widely used as a dietary supplement for its purported benefits for weight loss and glucose metabolism. Berberine is believed to lower blood glucose levels by increasing glucose uptake by the body’s cells and by preventing the breakdown of or increasing the secretion of a hormone called glucagon-like peptide 1 (GLP) (1, 2).

GLP stimulates insulin secretion — the hormone that lowers blood glucose — while inhibiting the liver from making glucose. Because it also decreases appetite and cravings, GLP plays a crucial role in weight management.

Ozempic (semaglutide) — a drug approved for diabetes, but now popularized for weight loss — works by mimicking GLP. This is why berberine is commonly referred to as “nature’s Ozempic.” 

Berberine May Lower Blood Glucose

There are a decent number of studies that have assessed the blood glucose-lowering effects of berberine, most of which have been conducted in patients with type 2 diabetes.

A 2019 review of 28 randomized clinical trials, all conducted in China, concluded that a berberine dosage between 300 mg and three grams daily for one to three months was associated with significant improvements in blood glucose control compared with a control (3).

Specifically, patients experienced a 9.7-mg/dL drop in fasting blood glucose and a 16.9-mg/dL drop after meals (postprandial blood glucose), translating to a significant improvement in hemoglobin A1C — a measure of average blood glucose over the previous two to three months.

Upon analyzing the data further, the researchers found that berberine combined with standard diabetes medications like metformin or glimepiride was more effective for lowering glucose than either intervention alone.

Further analysis also revealed that berberine had no advantage over other treatments like standard medications or lifestyle change when it was supplemented with for more than 90 days, taken by patients older than 60, or taken at a dose higher than two grams.

These results suggest that berberine can be effective for lowering fasting blood glucose and postprandial blood glucose in as little as 30 days or at most 90 days after which berberine may not be effective when compared with other interventions like standard medications.

Although the berberine dosage ranged from 300 mg to three grams daily, most studies used a dose between 0.9 and 1.6 grams taken in two or three doses daily.

Although the studies in this analysis point to the promising glucose-lowering effects of berberine, some of the studies were low quality, and all were conducted in China, limiting the ability to assume these results will occur in other populations.

As such, additional more robust trials that include a wider demographic are necessary before firm conclusions can be drawn on its usefulness for lowering glucose.

How Does Berberine Compare with Common Diabetes Medications?

Unlike commonly prescribed diabetes drugs, you don’t need a prescription for berberine, and it may be much less expensive than certain medications, depending on the pharmacy and insurance coverage.

And when it comes to adverse side effects, berberine is relatively well-tolerated, whereas common diabetes drugs can have unfavorable — but usually temporary — side effects.

It’s for these reasons that many people prefer “natural” alternatives to prescription drugs for managing conditions like high glucose or diabetes. Still, you might wonder whether berberine is more effective or lowers glucose faster than common diabetes drugs.

Berberine has most often been compared with metformin since the two possess similar effects on blood glucose but also on inflammation and blood lipids like cholesterol and triglycerides.

A review of four studies comparing berberine with metformin showed comparable effectiveness in lowering glucose, but a greater benefit when combined. The trials were conducted for one to three months, again suggesting it takes at least one month to experience berberine’s glucose-lowering effects. More significant decreases may be seen with up to three months of supplementation (4).

Similar findings have been demonstrated with other diabetes drugs like glipizide and rosiglitazone, suggesting berberine may be a suitable alternative or additive to them (3, 5).

Berberine can also lower high blood pressure, cholesterol, and triglycerides — a type of fat in the blood that when elevated increases the risk of heart disease — with some research suggesting a stronger lowering effect of blood lipids with berberine compared with metformin (6).

The lipid-lowering effect of berberine is attritibed to its ability to activate a protein called AMP-activated protein kinase (AMPK), that among many other things, suppresses fat production while promoting their breakdown (5).

Is Berberine Safe?

Many people perceive dietary supplements as “natural” and prefer them over prescription or over-the-counter drugs for managing certain health conditions.

While “natural” doesn’t equate to safe or side-effect-free, berberine has a strong safety profile with a low risk of adverse side effects.

Side effects associated with berberine are relatively mild and usually include gastrointestinal symptoms like diarrhea, constipation, and nausea (7).

Berberine may also interfere with certain medications by either increasing or decreasing their efficacy. This is especially true if you are taking drugs for diabetes since berberine can enhance their effectiveness and may lower glucose too much.

Fortunately, few episodes of hypoglycemia — which occurs when your blood sugars drop too low — have been reported in the studies that combine berberine with metformin or other diabetes drugs.

If you choose to try berberine, make sure you choose a product that has undergone third-party testing to ensure that you’re getting exactly what the label says — nothing more, nothing less.

Other Effective Ways to Lower Blood Glucose 

High glucose typically results from insulin resistance in which your body’s cells don’t respond well to insulin.

Consequently, your pancreas must produce more insulin to lower blood sugar and maintain healthy levels.

People with prediabetes usually have some insulin resistance, and if left uncontrolled, high blood sugar can advance to type 2 diabetes and cause other health problems.

Unless you have been diagnosed, you usually don’t know if you have insulin resistance, but you might experience symptoms like:

• Fatigue

• Extreme thirst

• Frequent urination

• Tingling or numb hands or feet

• Frequent infections or slow-healing wounds

If you have high blood sugar or a condition related to insulin resistance like diabetes, fatty liver disease, or polycystic ovary syndrome, the best way to improve your blood sugar is by making positive dietary changes

Fill up on foods like:

• Fruits: apples, avocados, berries, grapes, oranges, ect.

• Nonstarchy vegetables: broccoli, cauliflower, leafy greens, mushrooms, etc.

• Whole grains: brown rice, oats, popcorn, whole-grain breads

• Lean meats: poultry and lean cuts of beef and pork that say “loin” or “round”

• Plant proteins: black beans, chickpeas, green peas, lima beans, nuts, seeds

• Diary: Greek yogurt, cottage cheese, milk

• Beverages: black coffee, water, other calorie free drinks

At the same time, limit foods and ingredients that can worsen insulin resistance like:

• Added sugar: baked goods, candies, dairy desserts, sugary beverages like soda, specialty coffee drinks, and energy drinks

• Refined grains: crackers, chips, white rice and breads, most breakfast cereals

• Processed meats: bologna, bacon, deli meats, ham, hot dogs

• Other highly-processed foods: fried foods, most frozen meals, fruit snacks, granola bars

• Alcohol: all types

Exercise is another effective way to lower blood sugar since your muscles are the main site where insulin triggers glucose disposal.

For the greatest benefits, incorporate both endurance-type exercises like running and biking and resistance training that targets all major muscle groups — back, chest, shoulders, arms, core, and legs.

Weather permitting, taking a 20-minute walk after a meal can significantly reduce blood sugar (8).

Frequently Asked Questions About Berberine

Does Berberine Lower Blood Sugar?

Research suggests that supplementation with about 1 to 1.5 grams split into two to three doses daily for up to three months can lower fasting blood sugar, blood sugar following a meal, and hemoglobin A1C. However, much of the research has been conducted in China, so additional studies involving other populations are necessary.

Does Berberine Suppress Appetite

Although berberine may influence GLP-1 — a hormone that regulates appetite — there is no research to suggest it suppresses appetite. However, animal studies suggest it may reduce food intake (9).

Does Berberine Help With Weight loss?

Berberine supplementation may help you lose weight by improving blood sugar control and supporting lipid metabolism. However, the results are modest at best, with a review of 12 studies finding an average loss of 4.6 pounds (2.07 kg) over three months (10).

Does Berberine Cause Diarrhea?

While relatively safe and well-tolerated, some people have reported mild and temporary gastrointestinal symptoms like diarrhea and constipation with berberine supplementation.

The Bottom Line on Berberine

Berberine is an alkaloid extracted from the roots and bark of many types of plants, but most commonly, barberry. It has become increasingly popular as a "natural" remedy for lowering high blood sugar.

Research suggests that the alkaloid can significantly lower glucose — namely in people with type 2 diabetes — in just one month but its effects tend to fade when taken longer than three months. The optimal dose appears to be 1 to 1.5 grams split into multiple doses daily.

Still, the blood sugar-lowering effects may even rival commonly prescribed diabetes drugs like metformin while also providing other beneficial metabolic effects.

Berberine, however, should not be a replacement for lifestyle modifications, which, unlike berberine, are known to support healthy blood sugar management in the long term.

Therefore, if you are considering berberine supplementation, it's best to do so in combination with dietary change and exercise, but make sure to check with your medical provider first to see if it’s a safe fit.