Can You Take Berberine With Metformin?

In our latest question and answer, the pharmacist discusses whether or not there is a drug interaction between berberine and metformin.

Question

Is it okay to start taking Berberine (500 mg/3x day) when also on extended-release metformin?

Asked by KassRD On Oct 10, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Oct 10, 2022
Last updated Apr 26, 2024

Key points

  • Both berberine and metformin cause lower blood glucose (i.e. blood sugar). While unlikely, there is a risk that taking both could drop your blood sugar too low, so be sure to let your doctor know before combining them.

Answer

Thanks for reaching out! While there isn't a drug interaction per se between metformin and berberine, multiple studies, such as this one from Metabolism Journal, show that berberine can significantly lower blood glucose levels. While this can certainly be of benefit to diabetics, there is the risk that berberine might have additive effects when taken with other antidiabetic drugs, increasing the risk of hypoglycemia (low blood sugar).

Symptoms of hypoglycemia include:

  • Confusion
  • Sweating
  • Fatigue
  • Excess hunger
  • Lightheadedness
  • Headache
  • Shakiness

The good news is that both metformin and berberine are very unlikely to cause hypoglycemia on there own, but before using them together, be sure to speak with your doctor so you can be monitored for side effects and so they know that changes in blood glucose levels may be attributable to the addition of berberine to your regimen.

Berberine With Metformin Details

Berberine is not a plant as is commonly thought, but an alkaloid that is found in the roots, rhizome, and bark of many different plants including:

  • Goldenseal
  • Goldthread
  • Oregon grape
  • Barberry species
  • Phellodendron

Berberine is used for a variety of indications including canker sores, high cholesterol, and polycystic ovary syndrome (PCOS). However, berberine may have the most evidence for the treatment of diabetes. One large meta-analysis concluded that berberine can significantly reduce:

  • HbA1c
  • Fasting blood glucose
  • Post-prandial glucose

The effective dose of berberine used in studies varies but is generally around 500 mg two to three times daily

While berberine may be effective in reducing glucose levels, care needs to be taken when used with other diabetic medications, especially ones that are known to cause hypoglycemia. Although metformin has a lower risk of hypoglycemia than other anti-diabetic agents such as sulfonylureas (e.g. glipizide), combining it with berberine still increases the risk. It would be prudent to discuss the use of berberine with your doctor if you take metformin or other antidiabetic drugs.

Having said the above, it should be noted that several studies have shown that berberine and metformin can safely be used together with good effects.. One such study reported:

The hypoglycemic effect of berberine alone is not better than metformin. But berberine combined with metformin has good efficacy and safety in the treatment of T2DM [type 2 diabetes mellitus). The current clinical studies are low in methodology and reporting quality, which needs to be further proved by more high quality, large sample size and multi-center RCTs.
Wang, L. , Liu, D. , Wei, G. and Ge, H. (2021) Berberine and Metformin in the Treatment of Type 2 Diabetes Mellitus: A Systemic Review and Meta-Analysis of Randomized Clinical Trials.

So, overall, it appears there could be a benefit in using berberine with metformin, but as there aren't many studies on the matter, it would be prudent to let your doctor know before starting both so you can be appropriately monitored.

Final Words

Thanks so much for your question and reach back out to us anytime!

References

  • Metformin and berberine, two versatile drugs in treatment of common metabolic diseases, PubMed
  • Combination of metformin and berberine represses the apoptosis of sebocytes in high-fat diet-induced diabetic hamsters and an insulin-treated human cell line, PubMed
  • Berberine and Metformin in the Treatment of Type 2 Diabetes Mellitus: A Systemic Review and Meta-Analysis of Randomized Clinical Trials, Health

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