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2+ Banaba Leaf Extract Benefits + Side Effects

Written by Joe Cohen, BS | Last updated:

Banaba leaf extract is widely popular as an antidiabetic supplement, and its proponents claim it can help with weight loss. Does the science back them up? Read on to find out.

What is Banaba Leaf?

Lagerstroemia speciosa, commonly known as banaba, is a tropical tree widely grown in the Philippines. Traditional practitioners (and people looking for natural complements to their health management strategies) use it as antidiabetic [1].

Water and methanol (alcohol) extracts of this tree’s leaves are sold in capsule form and used to help lower blood sugar levels and promote weight loss. The capsules often contain other substances such as green tea, green coffee, tamarind, gymnema, black pepper, and/or metals like vanadium and magnesium [1].

Components and Mechanisms

Banaba leaf extract’s active components include corosolic acid, lagerstroemin, and gallotannins [2].

Corosolic acid lowered glucose in several animal and human trials, possibly by [3, 2, 4]:

  • Activating cells in the body to take up higher amounts of glucose
  • Discouraging the body from breaking down starches or sucrose into glucose molecules
  • Preventing the body from making glucose for energy from non-carbohydrates (opposes gluconeogenesis)

It also lowers fat levels (triglycerides and LDL, the “bad” cholesterol) [5].

Banaba contains ellagitannins, a type of molecule present in many common fruits and nuts such as pomegranates, strawberries, and almonds [6].

Ellagitannins like lagistroemin may increase glucose transport activity by activating glucose transporters (GLUTs) and promoting the production of more signaling (transmission) molecules. Transmission molecules like Nf-kB and MAPK, along with GLUTs, all help cells to absorb glucose and use it for energy [3, 7].

PGG, one of the banaba’s key gallotannins, discouraged fat cell production (adipogenesis) in cell studies. Gallotannins are a type of tannic acid, the class of compound, found in red wine, which reduced blood sugar in diabetic patients. These mechanisms have led some researchers to call for deeper investigations into banaba’s antidiabetic potential [3].

Banaba is a tropical tree with leaves rich in antioxidants and polyphenols. It is currently under investigation as a potential anti-diabetic aid.

Benefits of Banaba Leaf

Banaba leaf supplements have not been approved by the FDA for medical use and generally lack solid clinical research. Regulations set manufacturing standards for them but don’t guarantee that they’re safe or effective. Speak with your doctor before supplementing.

SelfDecode has an AI-powered app that allows you to see how Banaba Leaf benefits your personal genetic predispositions. These are all based on clinical trials. The orange neutral faces denote a typical genetic risk of developing conditions that Banaba Leaf counteracts.

Possibly Effective For

1) Blood Sugar Control

Banaba leaf may help lower blood sugar by increasing glucose tolerance. It can decrease glucose production in the body up to 30% and decrease the breakdown of storage molecules (like starch and glucagon) into glucose [3].

Unlike many antidiabetics, banaba has not been observed to promote weight gain [3].

In a year-long study, 15 diabetic patients took 100 mg of pure water-soluble banaba extract pills daily. At both 6 months and 1 year, the patients had significantly improved glucose tolerance. At the end of the year, they had up to a 16% decrease in their blood sugar levels but did not have low blood sugar (hypoglycemia) [1].

In another clinical trial, 24 patients with mild type 2 diabetes were given 3 tablets containing a mix of banaba, green tea, green coffee, and garcinia (tamarind) 3 times a day. The patients had an average blood glucose decrease of 13.5% [1].

In another 2-week study of 10 type 2 diabetic patients, the subjects took 32 mg or 48 mg banaba capsules (with a 1% concentration of corosolic acid) daily. At the end of the clinical trial, they had a 30% decrease in blood glucose levels [1].

Despite these promising results, the FDA has not approved banaba for lowering blood glucose. In order for it to reach the rigorous standards required for approval, large-scale clinical trials must be conducted to identify a safe and effective dose. Talk to your doctor before supplementing.


People with prediabetic insulin resistance may also benefit from banaba. In one clinical trial of 80 prediabetic adults, banaba extract improved insulin sensitivity and preserved pancreatic beta-cell function over 12 weeks. However, banaba did not reduce the degree to which blood sugar spiked after a meal. Further clinical trials are needed to determine how useful banaba might be in controlling insulin resistance and preventing progression into diabetes [8].

Taking banaba leaf extract reduced blood sugar and improved insulin sensitivity in multiple clinical trials.

Insufficient Evidence For

The following purported benefits are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of banaba leaf for any of the below-listed uses. Remember to speak with a doctor before taking banaba leaf, and never use it in place of something your doctor recommends or prescribes.

2) Weight Management

A common side effect of diabetes is weight gain, and unfortunately, many antidiabetic drugs prescribed to decrease blood sugar also seem to promote fat deposition. Banaba leaf, by contrast, has not been shown to increase weight gain.

Some researchers have suggested that banaba may prevent glucose storage molecules (like starch and glucagon) from breaking down. In combination with green coffee bean extract and vitamin D3, banaba improved markers of body composition (fat mass and fat free mass) in 30 volunteers with diabetes [9, 3].

It also decreased the production of fat cells (adipocytes) and lowered cholesterol and triglyceride levels [10, 3, 2, 4].

In a 60-day pilot study involving 30 participants, tablets containing a mixture of banaba, green coffee bean, vitamin D3, and Moringa oleifera leaf (horseradish) lowered body fat levels compared to placebo [11].

While the results of some clinical obesity trials are considered promising, banaba should never be used in place of what your doctor prescribes.

Animal & Cell Research (Lacking Evidence)

No clinical evidence supports the use of banaba leaf for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.

3) Antioxidant Activity

Banaba leaf extract reduced superoxide levels in rats. Superoxide, if left unchecked, can prevent cells from functioning properly and increase bacterial survival rate at an infection site [12, 13].

In diabetic mice, banaba extract helped increase levels of catalase, an antioxidant enzyme in the body. Catalase helps neutralize hydrogen peroxide (H2O2), a harmful, reactive oxygen compound [14, 12].

4) Heart Health

Banaba leaf extract contains gallotannins, which are a subclass of tannic acid. Tannic acid, a component of banaba, inhibits the production of endothelin-1, a protein that is heavily involved in heart disease [3].

A treatment of 0.072% corosolic acid, a major component in banaba, significantly lowered blood pressure in hypertensive rats [1].

5) Liver Disease

Nonalcoholic steatohepatitis is a liver disease that causes excess fat to build up in the liver. Excessive fructose (sugar) consumption is a major cause for this disease.

In rats, banaba extract decreased liver damage in rats with steatohepatitis and lowered total cholesterol and blood ALT levels [15].

6) Anti-Inflammatory Activity

Corosolic acid from banaba leaf extract helped prevent inflammation by inhibiting arachidonic acid formation in mice. This prevented prostaglandin and leukotriene formation [1].

Prostaglandins are the hormones that induce pain as a side effect, and leukotrienes are cells that release inflammatory cytokines [1, 16, 17].

In cells, banaba extract blocks the activation of the inflammation-causing NF-kappaB [18].

Banaba leaf extract has inhibited inflammation in animal and cell studies.

7) Antiviral Activity

Corosolic, gallic, and ellagic acid in banaba leaf extract inhibits enzymes that viruses use to take over human cells (proteases and reverse transcriptase). In cells, these acids help prevent viral infection from pathogens such as HRV-4 (Human Rhinovirus) and HIV [19, 3, 20].

The clinical usefulness of this activity is unclear, as it has never been tested in living animal models, let alone in humans.

8) Antibacterial Activity

In a bacteria study, banaba leaf extract derived from water (instead of alcohol) successfully impeded the growth of harmful bacteria such as S. aureus, B. subtilis, P.aeruginosa, and E. coli [21].

The antibacterial activity was shown to be possibly caused by the tannins and triterpenoids (bioactive molecules) found in banaba [21].

Cancer Research

Corosolic acid, one of the main components of banaba, is under investigation for its potential to kill isolated colon cancer cells in a laboratory setting [22].

Corosolic acid has also been found to inhibit 12-O-tetradecanoylphorbol-13 acetate (TPA), a compound that promotes tumor growth. Based on this result, researchers may test whether extracts or active compounds of banaba could prevent cancer development in animal models [23, 24].

There is currently nowhere near enough evidence to recommend banaba leaf in the prevention or treatment of cancer, but research is ongoing.

Limitations and Caveats

Many benefits of banaba were derived from extensive animal studies.

Human studies are few and often use a mixture of supplements, making it hard to conclude how much of the beneficial effects were solely caused by banaba extract. This is one of the reasons why banaba has not been approved by the FDA for any reason.

Side Effects & Precautions

No adverse effects have been found in clinical trials. Contrary to the logical expectation that the blood sugar-lowering capacity of banaba would cause low blood sugar (hypoglycemia), 6 clinical trials did not lead to any such effect [1, 2].

Drug Interactions

Herbs including fenugreek, garlic, guar gum, and/or horse chestnut, (which all help lower blood sugar levels), along with diabetic medication, theoretically will have enhanced effects when taken along with banaba [3].



There is no safe and effective dose of banaba extract because no sufficiently powered clinical trial has been conducted to find one. We can only discuss the doses which produced a benefit in existing clinical studies.

Banaba extract is commonly provided in pill form, either as an isolated extract or as an extract combined with other components.

Various studies have used 32 to 48 mg daily of banaba extract with a 1% corosolic acid concentration in adults. However, there is no set standard, and dosage recommendations will vary depending on the product and percent composition of banaba in the pills [3].

Pediatric studies have not been conclusive; we therefore caution strongly against giving banaba extract to children without the recommendation and supervision of a medical professional [3].

Buy Banaba Leaf Extract


Banaba is a tropical tree, the leaves of which are full of antioxidant polyphenols with the potential to improve insulin sensitivity, according to clinical trials. In humans, banaba has also reduced blood sugar and inhibited weight gain, while animal and cell studies have begun to investigate potential antimicrobial and anti-inflammatory activity.

Banaba leaf is generally considered safe to consume, though its safety profile is incomplete in pregnant women and children. Theoretically, it could interact with other compounds that reduce blood sugar, though this has not been demonstrated.

About the Author

Joe Cohen, BS

Joe Cohen, BS

Joe Cohen flipped the script on conventional and alternative medicine…and it worked. Growing up, he suffered from inflammation, brain fog, fatigue, digestive problems, insomnia, anxiety, and other issues that were poorly understood in traditional healthcare. Frustrated by the lack of good information and tools, Joe decided to embark on a learning journey to decode his DNA and track his biomarkers in search of better health. Through this personalized approach, he discovered his genetic weaknesses and was able to optimize his health 10X better than he ever thought was possible. Based on his own health success, he went on to found SelfDecode, the world’s first direct-to-consumer DNA analyzer & precision health tool that utilizes AI-driven polygenic risk scoring to produce accurate insights and health recommendations. Today, SelfDecode has helped over 100,000 people understand how to get healthier using their DNA and labs.
Joe is a thriving entrepreneur, with a mission of empowering people to take advantage of the precision health revolution and uncover insights from their DNA and biomarkers so that we can all feel great all of the time.


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