Calling berberine a natural weight-loss injection is both incomplete and misleading. We explain, as far as the research shows, this plant compound’s real effect on blood sugar and weight, why it cannot be compared with weight-loss injections, its side effects and its interactions with medicines.
The same promise has been doing the rounds on social media for some time: a cheap, herbal capsule that needs no prescription; its name is berberine, and its nickname is “the natural weight-loss injection”. For many people who cannot get the injectable medicines or do not want to take medication, it sounds attractive.
But the comparison is both incomplete and misleading. Berberine is a compound that really has been researched, and it has measurable effects on some metabolic markers. But neither the way it works nor the size of its effect is the same as that of weight-loss injections; what is more, it is not as innocent as people think. In this article we explain what berberine is, what the research shows and who should stay away from it.
What is berberine?
Berberine is a yellow, bitter-tasting compound found in the roots, bark and stems of some plants, such as barberry. It has been used for centuries in the traditional medicine of the Far East, particularly for diarrhoea and bowel infections. Today it is sold as a food supplement in capsule and tablet form, with claims about blood sugar, cholesterol and weight control.
How does berberine act in the body?
Berberine is thought to activate an enzyme that senses the energy status of cells. When this enzyme comes into play, cells make better use of the sugar in the blood, the liver produces less sugar and fat burning is supported. Its effects on gut bacteria are also believed to contribute to the results.
An important detail is this: the absorption of berberine from the bowel is quite low. A small part of the amount taken passes into the blood; this is one of the reasons both why its effect remains limited and why side effects on the digestive system are common.
What does the research show?
Blood sugar
In some of the studies carried out in people with type 2 diabetes, berberine has been reported to lower fasting blood sugar and the three-month average. This is the area in which berberine has the most evidence. But most of the studies are small and short; their quality of method differs greatly. The results are encouraging, but not at a level that would be enough to recommend berberine as a treatment for diabetes.
Blood fats
Some studies have seen a moderate fall in levels of LDL cholesterol and triglycerides.
Weight
This is what people really want to know, and it is also where the evidence is weakest. In reviews that assess the studies together, the average weight loss with berberine has remained at the level of a few kilos. This effect is no greater than that obtained with a moderate change in eating pattern.
Polycystic ovary syndrome
In polycystic ovary syndrome accompanied by insulin resistance, there are findings that berberine may improve some markers; but the data in this area are also limited, and for women planning a pregnancy there is a separate safety issue.
Why can berberine not be compared with weight-loss injections?
- The way it works is different. The medicines known as weight-loss injections bind to the receptors of gut hormones; they send a fullness signal directly to the appetite centre in the brain and slow stomach emptying. Berberine does not work through these receptors and does not suppress appetite in the way these medicines do.
- The size of the effect is different. The weight loss seen in the large studies of these medicines is many times greater than that reported in berberine studies.
- The level of evidence is different. Medicines are licensed after passing through long, controlled studies involving thousands of people. Berberine studies are small and short.
- The oversight is different. The content and dose of medicines are standard. With supplements, how much berberine a capsule actually contains can vary from product to product.
In short, mentioning the two in the same sentence is like comparing a bicycle with an aeroplane: both take you from one place to another, but they are not the same thing.
Side effects of berberine
The most common side effects involve the digestive system: diarrhoea, constipation, wind, bloating, abdominal pain and nausea. These complaints increase particularly with high amounts and when it is taken on an empty stomach. Taken together with medicines that lower blood sugar, it may contribute to blood sugar falling too far, and with blood pressure medicines to a fall in blood pressure.
Data on the safety of long-term use are limited; most studies have not lasted longer than a few months.
Who should not take berberine? Interactions with medicines
- Women who are pregnant or breastfeeding: Berberine can pass to the baby through the placenta and breast milk and may increase the risk of serious jaundice in the newborn. It should not be used in these periods.
- Babies and children: It should not be used.
- People taking diabetes medication or insulin: Because of the risk of low blood sugar, it should not be used without consulting a doctor.
- People taking blood pressure medicines and blood thinners: The effects can add to one another.
- People taking immunosuppressants after an organ transplant: Berberine can raise the level of these medicines in the blood.
- Everyone on regular medication: Berberine affects enzymes in the liver that take part in breaking down many medicines. For this reason it can increase or alter the effect of medicines taken alongside it.
- People with liver disease and those with surgery planned: A doctor’s approval is needed.
Does “natural” mean safe?
No. Many substances obtained from plants have powerful biological effects; a considerable share of medicines are of plant origin in any case. A compound that is effective enough to lower blood sugar is also effective enough to cause side effects and interactions.
Another problem with supplements is oversight. Food supplements do not go through the efficacy and safety studies that medicines do. Examinations of different products have shown that the amount of berberine in the capsules can be markedly less or more than is stated on the label. The fact that a product sells well online or is recommended by an influencer does not show that it is suitable for you.
What really works for weight and blood sugar
Methods that deliver as much as berberine does, or even more, and that have no side effects are already within our reach:
- An eating pattern with protein and fibre at every meal and with the type and amount of carbohydrate adjusted
- Short walks after meals and resistance exercise a few days a week
- Enough regular sleep
- Giving up sugary drinks
- Where needed, medication of proven effectiveness recommended by a doctor
A supplement is not a short cut that takes the place of these. You will find the basic principles of eating for blood sugar balance on the nutrition for insulin resistance page, and advice for people using medication on the nutrition during weight-loss injections page.
In brief
- Berberine is a plant compound whose effect on blood sugar is being researched.
- Its effect on weight is small; it does not have the same mechanism, evidence or level of effect as weight-loss injections.
- Side effects on the digestive system are common, and it interacts with many medicines.
- It should not be used in pregnancy, while breastfeeding or in children.
- Being natural does not mean that it is safe or suitable for you.
Frequently asked questions
Can berberine be used in place of the diabetes medicine my doctor prescribed?
No. Stopping the medicine your doctor recommended and taking a supplement instead can cause your blood sugar to go out of control. If you want to make a change to your treatment, discuss it with your doctor.
I have insulin resistance. Should I take berberine?
In insulin resistance the first and most effective step is diet, movement and sleep. If you are considering a supplement, do not start without consulting your doctor, who knows the medicines you take and your health.
How long can berberine be taken for?
There is not enough data showing that long-term use is safe. This is one of the reasons why open-ended use on your own is not recommended.
