Key points from article :
There is a possible cancer-causing impurity in some brands of metformin available in the US market.
According to US FDA some brands of metformin show high levels of N-nitrosodimethylamine (NDMA).
FDA may recall these brands from the market as they are not suitable for use.
High levels are found in metformin brands produced by 11 pharmaceutical companies.
Last year some generics of ranitidine and Zantac were recalled due to NDMA contamination.
