Mebendazole: What is it? Drug Uses, Dosages, Interactions, Side Effects, and Investigations

Also known as MBZ, it is commonly used to treat tapeworms or tapeworms (parasites).

Like other benzimidazoles , Mebendazole causes parasite death by interfering with tubulin function (tubulin feeds parasites and is also vital for cell division; it is a common cancer target for widely used chemotherapy drugs , such as paclitaxel, colchicine and vincristine).

MBZ, like the other benzimidazoles, binds to the colchicine-binding domain of tubulin and prevents glucose uptake.

These two traits make Mebendazole an important drug to consider for treating cancer.

But there is also the fact that Mebendazole belongs to the benzimidazole class of drugs, which is currently being used to target androgen receptors (AR +) (they are in 50-70% of HER2 + breast cancer patients ).

As one report says, “It is also possible that MBZ’s anticancer activity is mediated by additional molecular targets that have yet to be elucidated.”

There is not as much evidence on Mebendazole as Metformin , on its potential against cancer, but some studies (referenced below) show that the survival rates of those who take it increase by more than 60%.

The main problem with Mebendazole is that all the studies seem to refer to changes in the liver after people have taken it.

There are two current clinical trials of Mebendazole in progress, both for brain tumors:

  1. P hase I test at John Hopkins (study to be completed in November 2014) to see how many doses of Mebendazole to administer.
  2. A trial at Cohen Children’s Medical Center in New York to see if the standard dose of 100 mg Mebendazole twice a day is well tolerated.

Recommended dose of Mebendazole

Recommended doses for parasites include 100 mg twice daily for 3 days for ringworm or tapeworm, and 100 mg as a single dose for treating roundworm.

According to a patent document dating back to 1998, and it appears to have originated in Procter and Gamble, in the use of benzimidazoles to treat cancer, a dose of between 2 mg per kg of body weight and approximately 4000 mg kg of body weight.

The 40-year-old man with adrenocortical carcinoma referred to in the following investigation was administered a dose of 100 mg twice daily.

On the Inspire website, there is talk of people receiving even higher doses of 2500mg in the morning and 3000mg in the afternoon and evening.

In a current clinical trial for brain cancer, patients are treated on a 28-day cycle of 500 mg tablets three times a day.

Interactions and side effects of Mebendazole

Hepatic toxicity was observed for the combined treatment with Mebendazole + manumycin A.

In fact, liver toxicity appears to be seen in all Mebendazole treatments, including this PHD dissertation study, focusing on how MDZ specifically affects HER2 + cancers.

Other side effects:

  • Abdominal pain.
  • Diarrhea.
  • Dizziness
  • Drowsiness.
  • Headache.
  • Vomiting
  • Shaking chills.
  • Itch.
  • Redness
  • Hipo.
  • Ringing in the ears
  • Low blood pressure.
  • Bloody urine
  • Decrease in blood cells.


There is not much research on mebendazole.

This report describes only 2 individual cases of effectiveness in cancer patients (none with breast cancer); both went into remission.

One (a 40-year-old man with adrenocortical carcinoma), for whom all other options had been exhausted, did very well for 19 months and then progressed.

The other one went into remission in 6 weeks and then halved the dose and then stopped taking mebendazole completely. After a month, brain metastases appeared and they chose not to resume treatment with mebendazole.

That same article points to 2 clinical trials currently underway (none related to breast cancer), but both are in phase 1.

Most of the information about the drug focuses on its promise of use against lung and brain cancers, for example, in a study by John Hopkins in 2010, Mebendazole was shown to extend median survival by up to 63 percent. percent in mice that get a type of brain cancer.

In a study conducted in Italy in 2007, in mice that received an adrenal gland tumor (adrenocortical carcinoma), Mebendazole was shown to create apoptosis.

Mebendazole inhibited cancer cell invasion and migration in vitro and metastasis formation in vivo

There is a note in this research article published in 2002 that says that Mebendazole also shows effectiveness against breast cancer cells – the growth inhibitory effect was not limited to lung cancer cells.

This was due to the fact that MBZ also profoundly inhibited the growth of breast, ovarian and colon carcinomas and osteosarcomas, which produce IC 50 s that ranged from 0.1 to 0.8 μM (data not shown).

Benzimidazole shows promise for HER2 + patients in the March 2015 study – not using Mebendazole, but one of its sisters, named 5a.

“These results suggest that EGFR and HER2 gene amplification and protein overexpression are consistent with the increased sensitivity to 5a in vitro in several cell lines tested.

In accordance with these results, we propose that the antitumor activity of 5a in breast cancer cells may result from the inhibition of EGFR and HER2 activity ”

In another 2013 test-tube study of benzidazole looking at breast cancer cells that are resistant to chemotherapy, a variety of benzimidazoles (including MBZ and albendazole) were tested

From these tests they were found to cause significant growth arrest and apoptosis, with flubendazole and MBZ showing the highest level of cytotoxic activity. MBZ reduced cell survival by 63.1% at a dose of 0.5 μM.