A multistate outbreak of infant botulism cases has been linked to ByHeart-brand powdered infant formula. A total of 15 ByHeart-associated cases, all of which required hospitalization, have been reported across 12 states. A broader set of infant botulism cases, totaling 84 cases nationwide (including the 15 ByHeart-associated cases), is under investigation by state and federal public health agencies. Aside from ByHeart, no other infant formula brands or shared exposures that pose a risk to infants have been identified.

ByHeart Whole Nutrition Infant Formula represents 1 percent of the U.S. infant formula market, per the U.S. Food and Drug Administration (FDA). The agency does not anticipate supply shortages for parents and caregivers.

The California Department of Public Health’s (CDPH’s) Infant Botulism Treatment and Prevention Program (IBTPP) first notified the U.S. Centers for Disease Control and Prevention (CDC) of the outbreak, after noticing a spike in cases of botulism type A infections. IBTPP operates the only global source of infant botulism treatment worldwide. 

FDA is investigating the outbreak in coordination with CDPH IBTPP and state and local partners.

Outbreak Details and Timeline

According to information shared with FDA by IBTPP, between August 1, 2025 and November 10, 2025, a total of 84 infants nationwide have received treatment for infant botulism. Notably, more than 40 percent of the 36 infants who had known powdered infant formula exposure consumed ByHeart Whole Nutrition infant formula. This information shows that ByHeart-brand formula is disproportionately represented among sick infants in this outbreak, especially given that ByHeart represents an estimated 1 percent of all infant formula sales in the U.S., says FDA.

On November 8, preliminary laboratory results reported by CDPH suggest the presence of Clostridium botulinum in a can of ByHeart infant formula (lot 206VABP/251131P2) that was fed to an infant with infant botulism.

As of November 11, a total 15 cases of outbreak-associated infant botulism with confirmed exposure to ByHeart formula have been reported across 12 states: Arizona (1), California (2), Illinois (2), Kentucky (1), Minnesota (1), New Jersey (1), North Carolina (1) Oregon (1), Pennsylvania (1), Rhode Island (1), Texas (2), and Washington (1). Laboratory confirmation is pending for some cases.

All affected infants consumed ByHeart Whole Nutrition Infant Formula prior to illness onset, per FDA and CDC. No fatalities have been reported, although all cases required hospitalization.

Investigators have collected leftover formula samples from affected households for laboratory testing. Results are expected in the coming weeks.

Recall Information

Originally, ByHeart initiated a voluntary recall of just two specific lots of its Whole Nutrition Infant Formula (Lot 206VABP/251261P2 and Lot 206VABP/251131P2, both with “Use by” date December 1, 2026). On November 11, ByHeart Inc. expanded its voluntary recall to include all ByHeart formula products nationwide.

The products were distributed online and through major retailers nationwide. The lot code and “Use by” date are printed on the bottom of the formula cans.

Ongoing Investigations by Public Health Officials and ByHeart

FDA is working with ByHeart to ensure all potentially impacted products are removed from the market. The agency is also working to identify the source of contamination and assess whether additional products may be affected. Public health agencies are monitoring for further cases and coordinating treatment availability, particularly in Los Angeles County, California.

ByHeart Inc. says it is also conducting its own testing on all ByHeart batches, and that the firm will share the results of its testing as they become available. Interestingly, the firm said in a statement issued November 11, "Neither [ByHeart], nor FDA or CDC, have found Clostridium botulinum spores or toxins in any unopened can of ByHeart formula." This claim follows a different statement issued on November 9, in which the firm said, "Today, we were made aware by CDPH that a single, previously-opened sample from one of the two recalled batches of ByHeart formula tested positive for Clostridium botulinum, the bacteria that causes infant botulism." The November 9 statement is in line with information released by FDA.

FDA's Efforts to Improve Safety of U.S. Infant Formula Supply

The outbreak is occurring despite FDA’s promise to improve the quality, safety, nutritional adequacy, and resilience of the U.S. infant formula supply through a series of actions under the “Operation Stork Speed” initiative, announced in May. At the time, advocacy groups expressed skepticism over the agency’s ability to deliver on Operation Stork Speed given the significant Trump Administration cuts to FDA’s budget and workforce.

On November 10, the Reagan-Udall Foundation for the FDA published a report that captures key insights from stakeholder discussions on ways to improve U.S. infant formula safety and regulation, which were held to support FDA’s “Operation Stork Speed” efforts. Microbiological contaminants such as Clostridium botulinum and Cronobacter sakazakii were not a focus of the roundtable discussions or the report, however. 

Update, November 11, 2025: The article has been edited to reflect newly released information from FDA and ByHeart Inc. 

Update, November 14, 2025: The number of infant botulism cases linked to consumption of ByHeart formula has grown to 23 across 13 states. Additionally, according to FDA inspection reports and warning letters, ByHeart Inc. a history of food safety and hygiene violations at its production facilities.

Update, November 19, 2025: The number of infant botulism cases linked to consumption of ByHeart formula has grown to 31 across 15 states. 

Update, November 26, 2025: ByHeart Inc. has found Clostridium botulinum Type A in five of 36 samples across three lots. “Based on these results, we cannot rule out the risk that all ByHeart formula across all product lots may have been contaminated,” said the company.

As of November 26, the number of infant botulism cases in the associated outbreak has grown to 37 across 17 states. Additionally, FDA has released ByHeart facility inspection reports from as early as 2022 showing a history of food safety breaches.

Update, December 3, 2025: A total of 39 infants with suspected or confirmed infant botulism and confirmed exposure to ByHeart Whole Nutrition infant formula (various lots) have been reported across 18 states. All 39 infants were hospitalized; no deaths have been reported.

Update, December 16, 2025: As of December 10, a total of 51 infants with suspected or confirmed infant botulism and confirmed exposure to ByHeart Whole Nutrition infant formula (various lots) have been reported across 19 states. All 51 infants were hospitalized; no deaths have been reported.

On December 15, FDA issued an open letter to all food industry stakeholders describing firms’ legal obligations in the case of a food safety incident and outlining best practices for effective recalls. Separately, FDA sent warning letters to four major retailers—Target, Walmart, Kroger, and Albertsons—for failing to remove recalled ByHeart infant formula from store shelves.