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# CDER Touts Role in Metformin NDMA Studies
- URL: https://www.fdaweb.com/cder-touts-role-in-metformin-ndma-studies/
- Published: 2020-09-03T12:00:00.000Z
- Updated: 2026-09-14T16:27:37.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5147582

FDA says CDER’s use of multiple sophisticated testing methods enabled it to determine that only eight of 16 metformin products that were reported by a private laboratory as containing levels of N-nitrosodimethylamine (NDMA) above allowable intake levels contained higher levels of NDMA. The Center then ordered the recall of those eight products, leaving the other eight on the market for consumers to access.

In an online [post](https://www.fda.gov/drugs/news-events-human-drugs/rigorous-detection-nitrosamine-contaminants-metformin-products-balancing-product-safety-and-product?utm%5Fcampaign=New%20Spotlight%20on%20CDER%20Science%20-%20Rigorous%20Detection%20of%20Nitrosamine%20Contaminants%20in%20Metformin%20Products&utm%5Fmedium=email&utm%5Fsource=Eloqua), CDER says it moved quickly to determine the source of the discrepancy between the private laboratory results submitted in a citizen petition and those of FDA. It found that the private laboratory had relied on a single method that found the presence of NDMA above the allowable intake level in 16 of 38 metformin products it examined.

The CDER test results have been published in a peer-reviewed journal, the post says. It also notes that the CDER tests could have detected seven other nitrosamine compounds in addition to NDMA, but did not detect any.