Is berberine safe to use if you are taking medication?
Berberine can influence the blood levels of certain medications, although the clinical significance is unclear in most cases. If you are taking medication, discuss this with your doctor or pharmacist before using berberine.
Berberine inhibits two liver enzymes that break down many medications. At normally recommended doses this effect is weak, but it does exist. In theory, blood levels of certain medications could therefore rise slightly. How large that risk is in practice is not well understood: the evidence base is thin and the available studies sometimes contradict one another.
One clinical study in people with type 2 diabetes showed that goldenseal root (of which berberine is the active compound) can lower blood levels of metformin by around 20%, but only at low metformin doses (500 to 750 mg per day). At higher doses of 2000 mg or more this effect disappeared. Blood sugar values did not change on average. Doctors are advised to be alert to this, even though the practical significance appears limited. Animal research, incidentally, shows the opposite: in rats, metformin levels actually rose. That finding cannot simply be applied to humans.
Possible interactions between berberine and blood pressure medications have also been described, but how large these are and whether they make any clinical difference cannot be determined from the available evidence. Large, long-term safety studies are still entirely lacking. There is also limited indication that goldenseal root extract may potentially be harmful to nerves, the liver and the skin (when exposed to sunlight), but the evidence for this is too thin to draw firm conclusions.
If you are using berberine alongside medications, always discuss this with your doctor or pharmacist. This applies in particular if you are taking metformin, blood pressure medications, or medications that are sensitive to fluctuating levels. In research on blood sugar regulation in type 2 diabetes, participants were given 500 mg three times daily. This is something to do together with your doctor.
This answer is based on one independently funded study in people with type 2 diabetes (concerning the interaction with metformin), supplemented by animal research in rats and several review studies. The researchers themselves note that large, long-term clinical safety studies are lacking and that rare side effects and interactions have not yet been sufficiently mapped. The evidence is therefore narrow and the uncertainty substantial, particularly regarding interactions with medications other than metformin.
How much berberine do you need per day?
For blood sugar regulation in type 2 diabetes, 500 mg three times daily (1500 mg per day) for at least 8 to 12 weeks is the best-supported schedule; for cholesterol, 500 mg twice daily is the starting point. If you have a condition or use medication, always discuss this with your doctor.
What do we know about berberine patches?
Berberine patches show interesting results in laboratory and animal research for wounds, eczema, psoriasis and joint complaints, but no studies in humans have yet been conducted, so no clinical conclusions can currently be drawn from them.
Does metformin help you live longer in good health?
For people with diabetes, metformin has a reasonably well-supported health benefit, but as an anti-ageing agent for healthy people it has not yet been proven. Wait for the results of the TAME study before drawing conclusions.
What are the side effects of metformin?
Metformin causes gastrointestinal complaints such as diarrhoea, nausea and vomiting in a substantial proportion of users. Discuss with your doctor whether the dose can be built up gradually, or consider an alternative if the complaints persist.
Does berberine help with weight loss?
Berberine leads to modest weight loss in some studies, but a large, well-designed study found no effect on visceral abdominal fat. It is not a powerful slimming agent, but may offer additional benefits for people with elevated cholesterol.
Does berberine help against high blood sugar (the natural metformin)?
Approach this with caution. Berberine measurably lowers blood sugar, but EFSA was unable to establish a safe intake level due to indications of DNA damage and liver injury, an EU procedure is underway that could lead to restrictions, and it has strong interactions with medications. Do not use it on your own, especially not alongside diabetes medication or during pregnancy.