Berberine: Dangers, Side Effects, and ANSES Opinion

Berberine is currently the most discussed plant extract, and the query that most often accompanies it in France is not "benefits" but "danger". This is legitimate, and for a reason that few pages mention: the French health agency issued an opinion on this ingredient in a public statement in 2019. Here's what berberine is, what this opinion says, where the pancreas question comes from, and what regulations actually allow to be written.

What is berberine?

Berberine is a plant alkaloid, with a characteristic bright yellow color, present in the bark and roots of several plants: barberry (Berberis vulgaris), Chinese coptis (Coptis spp.), and goldenseal (Hydrastis canadensis). Its content varies greatly depending on the species, ranging from 0.5 to 9% of the root.

It is therefore not a nutrient. It is neither a vitamin, nor a mineral, nor an amino acid: it is a concentrated plant molecule, long used as a dye before being used in traditional Chinese and Indian herbal medicine.

This distinction is not a vocabulary detail. A nutrient has a reference nutritional value, regulated claims, and an established safety profile. A standardized plant extract does not — and this is exactly where the questions discussed in this article come from.

What claims are authorized for berberine?

None. It must be stated as clearly as that: no health claim is authorized in Europe for berberine. Neither on blood sugar, nor on cholesterol, nor on weight, nor on transit, nor on anything else.

However, you will read many things about this molecule, often confidently worded. None of this can legally appear on a French label or product sheet, and we will not write it here either.

This is a fundamental difference from the ingredients we usually talk about. Magnesium has nine authorized claims; creatine, two. Berberine, zero. When an entire aisle relies on assertions that no text authorizes, the reader deserves to know before buying.

What does ANSES say about berberine?

This is the core of the matter, and the information is public. Referred in April 2018 by the Directorate General for Competition, Consumer Affairs and Fraud Control, ANSES issued on August 1, 2019 an opinion on the safety of food supplements containing berberine (referral 2018-SA-0095).

The general conclusion

The agency concludes that, based on available toxicological data, it is not possible to exclude an effect on human health linked to the consumption of these products. This is a cautious formulation, and it must be read for what it is: neither a prohibition nor a blank check, but an acknowledged observation of uncertainty.

The surprising figure

ANSES has established an indicative toxicological value of 1.7 µg per kilogram of body weight per day, or approximately 0.1 mg per day for a 60 kg person. For comparison, Belgium had set a limit of 10 mg per day: the French value is forty times lower.

Let's be frank, because this is the passage that commercial pages gloss over: clinical studies on berberine use doses of around 400 to 1,500 mg per day, and market supplements are in this order of magnitude. The difference with the indicative value of ANSES is therefore considerable, by several thousands of times.

An indicative toxicological value is not an enforceable maximum dose, and it was constructed from data that the agency itself considers limited. But it is the only numerical benchmark issued by a French authority on this ingredient, and it cannot be overlooked in an article titled "danger".

The agency's recommendations

ANSES recommends, in particular, setting a maximum berberine content significantly lower than the Belgian 10 mg, strengthening labeling with explicit warnings on drug interactions, excluding berberine-containing plants from common foodstuffs, and not tolerating any health claims — since none are approved.

This is the same approach we followed for another highly sought-after extract in our article on the ANSES opinion regarding ashwagandha: to report the agency's position, without hardening or softening it.

Berberine and the pancreas: where does this question come from?

This is one of the most frequent searches for this molecule, and the honest answer comes in two parts.

Firstly: the ANSES opinion does not report any pancreatic damage. The adverse effects recorded by the nutrivigilance system between 2009 and 2018 are three in number — headaches and dizziness, angioedema, asthenia with myalgias. The pancreas is not among them. The effects described in clinical trials are moderate gastrointestinal disorders at high doses.

Secondly: the scientific literature on berberine and the pancreas leans the other way. Available works are cell and animal studies exploring protective effects — on pancreatic beta cells or in pancreatitis models. These are preclinical data: they do not allow any assertion in humans, and especially no claims, since we have just seen that none are authorized.

So where does the concern come from? Most likely from the molecule's real pharmacological activity. ANSES recognizes its hypoglycemic and hypolipidemic properties, meaning an action on blood sugar and blood lipids. As soon as a product affects blood sugar, the association of ideas with the pancreas and insulin comes naturally.

The documented risk, however, is not pancreatic damage: it is hypoglycemia in a person already on antidiabetic treatment. This is not the same thing, and it is much more concrete.

Drug interactions: the real risk

This is the central point of the opinion, and the one that should decide your purchase.

Berberine acts on hepatic enzymes and intestinal transporters that participate in the metabolism of many drugs. It can therefore modify the blood concentration of a treatment taken at the same time, in either direction. ANSES specifically cites:

• cyclosporine, whose bioavailability increases by 34.5% to 88.9%;
• tacrolimus, with an increase in renal toxicity;
• digoxin, whose exposure can increase by up to 70%;
• midazolam, with an exposure increased by up to 40%;
• hypoglycemic drugs, with an increased risk of hypoglycemia;
• macrolides, with a cumulative cardiac risk.

The agency's conclusion is unambiguous: the consumption of supplements containing berberine in combination with medicinal treatment is not recommended. Not "to be monitored", not "to be spaced out": not recommended.

Read this list for what it is. Cyclosporine, tacrolimus, and digoxin are drugs with a narrow therapeutic window: a concentration variation of 40 or 70% is not an adjustment, it's a problem. If you are taking any treatment, the question should be put to your doctor or pharmacist before opening a bottle — not to the salesperson, and not to a forum.

What side effects have been reported?

Digestive disorders are the most frequent: nausea, gastric discomfort, diarrhea, constipation. They appear mainly on an empty stomach and at high doses. Taking them with a meal significantly reduces them.

Headaches and dizziness are among the cases reported to nutrivigilance, with causality deemed possible.

An allergic reaction — angioedema — has been reported. This is rare, but documented.

Asthenia and muscle pain complete the list of the three cases recorded during the 2009-2018 period.

Three reports in ten years is few in absolute terms. But nutrivigilance relies on voluntary declarations, and ANSES itself recommends strengthening surveillance for this ingredient. A low number of reports is not proof of safety.

Berberine, weight loss and abdominal fat

This is the most common promise, and it deserves a direct answer: no weight loss claim is authorized for berberine in Europe, and this product is not a fat burner.

The molecule has recognized pharmacological activity on blood sugar and blood lipids — this is precisely what ANSES says, and it is also what underpins its warnings. Pharmacological activity is not a selling point for a food supplement: it is rather a sign that we are approaching the realm of medicine, where a prescription and follow-up exist.

Regarding weight loss itself, what works remains caloric deficit and physical activity. Our article on fat burners details what these formulas actually contain and what they can claim.

Who should abstain?

• People on medication, whatever it may be. This is ANSES's explicit recommendation, and it primarily concerns drugs with a narrow therapeutic window.
• Pregnant and breastfeeding women. Not recommended by the agency.
• People with G6PD deficiency (glucose-6-phosphate dehydrogenase), a population specifically identified in the opinion.
• Diabetic people. Due to the hypoglycemic activity and the risk of addition with ongoing treatment.
• Children and adolescents, for whom this type of concentrated extract has no place.
• People with hepatic or cardiac pathology, given the metabolic pathways involved and the cardiac interactions cited.

Let's add a special case: berberine can be extracted from goldenseal (Hydrastis canadensis), a plant classified as possibly carcinogenic to humans — group 2B — by the International Agency for Research on Cancer in 2016. The source plant appears on the label: it is worth reading.

How to read a berberine label?

The source plant, first. Berberis vulgaris, Coptis chinensis or Hydrastis canadensis are not equivalent, if only with regard to the IARC classification mentioned above. A product that does not indicate its source plant does not give you this information.

Milligrams, not just percentage. "Standardized to 97% berberine" describes the concentration of the extract, not the swallowed dose. Without the amount of extract per capsule, this percentage does not allow for any calculation. It's the same arithmetic as that of mineral salts, explained in our article on magnesium bisglycinate: a percentage without milligrams means nothing.

Warnings present or absent. ANSES recommends explicit labeling on drug interactions. A manufacturer who lists their contraindications in black and white gives you one signal; a manufacturer who mentions none gives you another.

Displayed claims. Any mention of an effect on blood sugar, weight, or cholesterol attributed to berberine is irregular. This is an immediate criterion of seriousness, and it costs nothing to check.

What accompanies berberine in the formula. Chromium, for example, is a regulated trace element, with two authorized claims — "contributes to the maintenance of normal blood glucose levels" and "contributes to normal macronutrient metabolism" — usable above a threshold per serving. Check that the quantity is published, otherwise the threshold is not verifiable, and see what your multivitamin already contains to avoid duplication.

Berberine in pharmacies or specialized stores?

Both channels sell berberine supplements, and the regulatory framework is the same for all: no authorized claims, no French dose limit established to date, and the ANSES opinion applies equally.

The difference lies in what you are told at the time of purchase. The only question that really matters before buying berberine is: "Are you on medication?" If the answer is yes, the purchase awaits the answer from your pharmacist or doctor.

We only have one reference of this type in our catalog, IO Genix Berberine Complex, and its product sheet lists its contraindications without sugarcoating them. At the store, it is one of the rare products that we sometimes refuse to sell on the spot: when a client announces ongoing treatment, we prefer that they come back after talking to their pharmacist.

Frequently asked questions about berberine

Is berberine dangerous?

ANSES concluded in its opinion of August 1, 2019 that it is not possible to exclude an effect on human health, and advises against the consumption of berberine supplements in combination with medicinal treatment. It established an indicative toxicological value of 1.7 µg per kilogram per day, or approximately 0.1 mg per day for 60 kg — well below the doses used in studies and market products.

Is berberine dangerous for the pancreas?

ANSES's opinion does not report any pancreatic damage: the three cases recorded by nutrivigilance between 2009 and 2018 concern headaches and dizziness, angioedema, asthenia with myalgias. Scientific work on berberine and the pancreas is preclinical and explores rather protective effects, without allowing any conclusion in humans. The truly documented risk is hypoglycemia in association with antidiabetic treatment.

What are the side effects of berberine?

Mainly digestive disorders — nausea, gastric discomfort, diarrhea, constipation — especially on an empty stomach and at high doses. Headaches, dizziness, asthenia with myalgias, and angioedema have been reported to nutrivigilance.

Can berberine be taken with medication?

ANSES explicitly advises against it. Berberine alters the metabolism of many drugs: cyclosporine, tacrolimus, digoxin, midazolam, hypoglycemic agents, and macrolides are cited in the opinion, with exposure variations of up to 70%. If you are on treatment, this question belongs to your doctor or pharmacist.

Does berberine cause weight loss?

No weight loss claim is authorized in Europe for berberine, and it is not a fat burner. Weight loss relies on caloric deficit and physical activity.

When to take berberine?

With a meal rather than on an empty stomach: this is the instruction that most changes digestive tolerance, with nausea being significantly more frequent on an empty stomach. No specific time is imposed by a claim, as none exist.

What dose of berberine per day?

No reference dose is established in France. ANSES has proposed an indicative toxicological value of approximately 0.1 mg per day for 60 kg, Belgium a limit of 10 mg, and clinical studies use 400 to 1,500 mg. These three figures do not describe the same thing, and this is precisely what makes the subject difficult. Follow the manufacturer's dosage without exceeding it.

Is berberine suitable for diabetics?

Not without prior medical advice. ANSES recognizes berberine's hypoglycemic activity and cites an increased risk of hypoglycemia in association with antidiabetic treatment. This is a conversation to have with the doctor who manages your treatment.

What is the best source plant for berberine?

The question to ask is less about the "best" than about the one to be aware of: goldenseal (Hydrastis canadensis) has been classified as possibly carcinogenic to humans, group 2B, by IARC since 2016. Barberry (Berberis vulgaris) and coptis are the other common sources. The plant must appear on the label.

Is berberine banned in France?

No, berberine supplements are still marketed. No maximum content is set by French law to date, and ANSES specifically recommends establishing one, significantly lower than the Belgian 10 mg. No health claim is authorized for this molecule.

Does berberine have any interest in bodybuilding?

No claim recognizes any effect on performance, muscle mass, or recovery. It is not a sports nutrition product, and the ingredients that have claims in this area are proteins and creatine.

This is one of the rare ingredients in the section where we spend more time explaining contraindications than describing the product. If you hesitate, come to our store in Vendargues, about ten minutes from Montpellier, and bring a list of your treatments — that will provide the answer. The berberine section is online, and our article on coenzyme Q10 addresses the same questions about drug interactions.