The companies blamed the recall on the presence of N-nitrosodimethylamine (NDMA), an impurity thought to be produced because of changes in manufacturing that is classified as a probable cancer-causing agent.

The Food and Drug Administration issued an announcement about the voluntary recalls on July 13. Twenty-two other countries have also issued varlsartan recalls.

The specific products impacted are valsartan sold by Major Pharmaceuticals, Solco Healthcare, and Teva Pharmaceuticals Industries, along with valsartan/hydrochlorothiazide (HCTZ) sold by Solco Healthcare and Teva Pharmaceuticals.

“We have carefully assessed the valsartan-containing medications sold in the United States, and we’ve found that the valsartan sold by these specific companies does not meet our safety standards,” Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, said in a statement. “This is why we’ve asked these companies to take immediate action to protect patients.”

The FDA recommends that patients continue taking the medication until they can get a replacement, because it is used to treat “serious medical conditions.” The agency also recommends that consumers determine if they are taking a recalled product, find the company-specific recall instructions, and contact their pharmacy and physician.

A FDA spokesperson told Fortune that specific information including returns and dates of the impacted medication will be provided by the pharmaceutical companies and posted to the FDA’s website. Solco Healthcare’s information is already on the FDA’s website, information from Major Pharmaceuticals can be found on its website, and early Monday evening Teva Pharmaceuticals USA released a statement with information about the recall.

Prinston Pharmaceutical, doing business as Solco Healthcare, is recalling “all lots” of Valsartan tablets manufactured by Zhejiang Huahai Pharmaceutical.

Impacted medication includes, “40 mg, 80mg, 160mg, and 320mg; and Valsartan-HCTZ Tablets, 80mg/12.5mg, 160mg/12.5mg, 160mg/25mg, 320mg/12.5mg, and 320mg/25mg, within expiration dates from July 2018 to Jan. 2020,” according to a statement. The company is asking pharmacies to “immediately return the product.”

Major Pharmaceuticals said that the recalled products were distributed to “wholesale and retail facilities, including hospitals and pharmacies” nationwide. The impacted medications were supplied by Teva Pharmaceuticals, and include Valsartan 80mg tablets and Valsartan 160mg tablets with the expiration dates of July 2018, Feb. 2019, or May 2019. (A full list of lot numbers can be found here.)

Teva Pharmaceuticals USA also confirmed the recall, saying in a statement that “29 lots of single and 51 lots of combination valsartan medicines” which were manufactured by Zhejiang Huahai Pharmaceutical and distributed by the Actavis label, were being recalled due to the detection of NDMA. (A full list of recalled medications can be found here.)

So far, neither Prinston Pharmaceutical, Major Pharmaceuticals, nor Teva Pharmaceuticals has received any reports of adverse reactions to the recalled products. Consumers can report issues to the FDA through the agency’s MedWatch Adverse Event Reporting program, which can be reached via phone, fax, by regular mail, or online.

Updated 7/16/2018 at 5:30 p.m. PDT: This piece was updated to include information about Teva Pharmaceuticals USA’s recall of valsartan medication.