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A New Carcinogen DMF Discovered in Valsartan BP Pills

It is hard to believe that yet another potential carcinogen has been found contaminating ARBs. The carcinogen DMF was detected in some valsartan BP pills.

And now there are FOUR potential carcinogens found in blood pressure medicines called ARBs (angiotensin receptor blockers). For almost a year, Americans have faced repeated recalls of BP pills like irbesartan, losartan and valsartan. These are among the most prescribed blood pressure medicines in the country. Nitrosamines, including NDEA, NDMA and NMBA, were found in tens of millions of pills. Now a fourth probable carcinogen–DMF–has been detected in some valsartan tablets. Are you getting fed up?

Is the Potential Carcinogen DMF in Your Valsartan?

Valisure is an online pharmacy in New Haven, CT. It has a laboratory that tests every batch of medicine the pharmacy sells. It discovered dimethylformamide or DMF in valsartan made by a number of different companies.

According to the CDC and the National Institute for Occupational Safety and Health (NIOSH) Publication Number 90-105

“Dimethylformamide (DMF) is a colorless, water-soluble liquid with a faint ammonia-like odor. This organic solvent is used in acrylic fiber spinning, chemical manufacturing, and pharmaceutical production; it is also present in textile dyes and pigments, paint stripping solvents, and coating, printing, and adhesive formulations [NIOSH/OSHA 1981].

DMF and Health Concerns:

The NIOSH report describes several potential problems with DMF:

  • Liver Injury
  • Cancer
  • Skin problems
  • Abdominal pain, constipation, nausea
  • Headache, weakness, dizziness

How did DMF Get into Valsartan?

In its Citizen Petition to the FDA, Valisure offered these disconcerting observations:

“Valisure has tested and detected high levels of N,N-Dimethylformamide (“DMF”) in specific lots of the drug valsartan, an angiotensin II receptor blocker (“ARB”). DMF is a chemical that was reclassified in 2018 as a Group 2A probable human carcinogen by the World Health Organization (“WHO”) and International Association for Research of Cancer (“IARC”).”

“In the recent wave of ARB recalls due to the discovery of probable human carcinogens, it has become apparent that the switch in the manufacturing industry to the use of the DMF solvent may be largely responsible for the formation of nitrosamine carcinogens such as N-nitrosodimethylamine (“NDMA”) and N-nitrosodiethylamine (“NDEA”). The carcinogenic nature of nitrosamines in general, and specifically NDMA and NDEA, has been well characterized in the scientific community since as early as the 1960s.

“Despite the very strict FDA recommendations for daily limits of NDMA and NDEA, the chemical DMF, which since 2018 has shared the same Group 2A carcinogenicity classification, currently has an FDA permitted daily exposure limit of 8,800,000 nanograms, which is 9,166,667% higher than the acceptable intake limit of NDMA. This disparity lacks a rational basis and is of significant concern, particularly because of Valisure’s recent findings that high levels of DMF exist in certain on-market lots of valsartan medication.”

What Can Patients Do About the Probable Carcinogen DMF?

Since the FDA allows drug companies to use DMF as a solvent in the production of valsartan, it is hard to know if your valsartan is “clean.” According to the petition to the FDA from Valisure, DMF was “not detected” in valsartan made by Alembic (160 and 320 mg pills) and most of the valsartan made by Cadista. You will find details about products that did appear to have DMF in the petition at this link.  

Can We Trust the FDA’s Oversight?

There have been so many recalls over the last several months that we wouldn’t blame you for tuning out. People can only take so much nasty news. After awhile it becomes overwhelming.

That said, we think our recent interview with Katherine Eban describes the many problems with FDA oversight in convincing detail. Here is a link:

Show 1169: What Are the Problems with Generic Drugs?

Mitch responded to an article we wrote titled “Why Aren’t Docs Outraged by Inadequate Generic Drug Approval?

“Greetings. I took the generic of valsartan from the now banned Zhejiang Huahai Pharmaceutical Co., Ltd. for several years. I took it because that’s what my pharmacy stocked. And this was a major chain. I trusted them. This was my first mistake.

“Since that time, I have become a reluctant expert in Indian and Chinese generics, thanks in part to People’s Pharmacy, Katherine Eban, and my own research. What I have found is shocking. I was prescribed a replacement – irbesartan, and went to pick it up and found it was also made by Zhejiang Huahai. Yep, after all the news was out, including the ban on imports, several major pharmacy chains were selling their remaining supply from this company.

“The irbesartan was recalled about a month or two later. Shocker. But I was aware it was made by them only after insisting to see the supplier’s bottle with the manufacturer on it. I refused it. I have tried to find the “cleanest” generic out there for an ARB, but they keep getting recalled.

“I have called the FDA and spoken to their pharmacists. I have asked why one year later they still haven’t finished testing these drugs for ‘impurities.’ I have learned that there are now five (5) known impurities in the ARBs, including the latest discovered by none other than Valisure – the online pharmacy that tests medication before selling it to consumers (what a novel concept huh?). They have found a new chemical called DMF or dimethylformamide (also a carcinogen) in valsartan. Apparently from cheap solvents.

“Valisure filed a Citizen Petition with the FDA you can find here
Good for them. Unfortunately, the FDA’s ‘safe’ ARB listing doesn’t take this DMF contamination into account. See the Bloomberg article here.

“The drugmakers questioned about this said:

“they don’t have complete visibility into their supply chain”

“Shocker. One also said the DMF was likely caused by the testing/analysis! Now that’s a good one.

“My god, folks. We’re in trouble here. I agree with this People’s Pharmacy article. Doctors don’t seem to be concerned about this. Or, they are concerned, but aren’t taking action. It baffles me. I read in the article I included above that Cleveland Clinic has pushed the American Medical Association to assess whether more needs to be done to protect the U.S. drug supply. Hey AMA, let me save you the time and effort. The answer is “YES!” Get on it and make a difference by getting out ahead of this. I predict it will get worse before it gets better.

“Please everyone, learn how to research your drug manufacturers. Read their FDA warning letters. Ask yourself whether your pharmacy is working for you, or for your insurance company. Do it like your life depends on it.

“A disclaimer – I have nothing to do with Valisure except that I have now become a loyal customer! Thanks People’s Pharmacy for mentioning them.”

What Can You Do?

To learn more about using generic drugs wisely, you may wish to read our eGuide to Saving Money on Medicine.  It describes our travails with the FDA and offers tips on how to get quality medications without paying an arm and a leg. You may also wish to check out Valisure’s testing process.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
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