Perfect Day, a startup pioneering the production of whey proteins via precision fermentation, has been hit with a lawsuit alleging it is misleading consumers about its animal-free dairy products.
The complaint* focuses on beta-lactoglobulin, a whey protein (brand name ‘ProFerm’) that Perfect Day produces from a genetically engineered strain of the filamentous fungus Trichoderma reesei. The ingredient is the subject of an FDA no questions letter issued in 2020 affirming its GRAS (Generally Recognized as Safe) status.
In the lawsuit, filed in the District of Columbia, plaintiffs the Organic Consumers Association and Toxin Free USA argue that “Perfect Day markets ProFerm as safe, environmentally friendly, identical to cow-derived whey protein, capable of creating milk identical to cow’s milk—including its nutritional profile—and free from genetically modified organisms. The reality is markedly different.”
According to the plaintiffs, tests conducted by The Health Research Institute (HRI) show that ProFerm contains a significant amount of residual fungal protein from the genetically engineered host microbe.
Plaintiffs: Fungal protein levels are higher than stated
While Perfect Day’s GRAS notification claims that tests by the Food Allergy and Resource Program (FARRP) at the University of Nebraska-Lincoln indicate that ProFerm contains up to 6.7% fungal protein, the plaintiffs allege the figure is far higher.
“Advanced testing reveals that 86.6% of the product consists of fungal proteins,” a figure that some industry sources says seems unlikely given that such a high fungal protein content would have an obvious sensory impact.
Similarly, the wording of the lawsuit is inconsistent, as one section says “testing reveals that 86.6% of the product consists of fungal proteins,” implying that the bulk of the product by weight consists of fungal proteins, whereas another section says “86.6% of the proteins in ProFerm are fungal proteins” which could mean the fungal proteins’ percentage of the overall product by mass is much lower than 86.6%.
For example, if there are seven different kinds of proteins in ProFerm, and six of them are fungal, that might represent 86% of the proteins, but if the fungal proteins only account for a tiny fraction of the mass of the product, Perfect Day’s contention that fungal residues only account for up to 6.7% of the product (by weight) could be accurate.
However, HRI chief scientist John Fagan, PhD, told AgFunderNews that the testing showed that the product comprised primarily fungal proteins “by weight.”
Fungal metabolites
According to the lawsuit, “Another group of waste byproducts in ProFerm consists of fungal compounds… which are likely byproducts and metabolites produced by the GMO during fermentation,” adds the complaint.
Most of these fungal proteins and compounds “are not known in scientific literature and have never before been studied as part of the human diet,” claim the plaintiffs. “Their toxicity, allergenicity, effect on nutrition and microbiome function, and safety for human consumption are unknown.”
HRI’s analysis also highlights nutritional differences between cow’s milk and ‘animal-free milks’ on the market containing ProFerm, although the brands referenced in the lawsuit do not claim to have an identical composition to cow’s milk. Strive Freemilk, for example, spells out on the front of pack how it differs nutritionally from regular cow’s milk (more protein, less sugar).
Finally, the plaintiffs take issue with Perfect Day’s characterization of ProFerm as non-GMO as it is “the product of a GMO,” although US food labeling laws do not require products that contain no detectable GM material to be labeled as bioengineered, something Perfect Day notes on its website: “Genetic engineering is part of our process, but there’s no detectable genetic material present in our protein.”
Perfect Day GRAS notice: T.reesei has long history of safe use
Perfect Day did not respond to a request for comment from AgFunderNews, but has repeatedly explained that its host microbe is “completely filtered out” of the final beta lactoglobulin product, telling Green Queen last year that it questioned the “methods and materials” used by HRI to test samples of Bored Cow (an ‘animal-free’ milk containing Perfect Day’s protein).
In its GRAS notification to the FDA, Perfect Day notes that FARRP determined that the beta lactoglobulin samples it tested did not contain “sufficient residual fungal proteins to present allergenicity concerns.”
According to its GRAS notice, Perfect Day conducted a literature review and “found no reports that implicate T. reesei with human, animal, or plant disease or allergenicity among healthy adults. Perfect Day supports its conclusion using published scientific literature, the long history of safe use of T. reesei in industrial scale food enzyme production, and the results of bioinformatic analysis of T. reesei proteins conducted by the FARRP.”
Further, “FDA’s GRAS Notice Inventory lists 17 notices involving production of both endogenous and exogenous enzymes using fermentation of genetically modified T. reesei that have received no questions letters from the FDA,” added the startup.
The plaintiffs say they are not mounting a class action or seeking damages but seeking seeking declaratory relief and an injunction to “stop the deceptive marketing of ProFerm,” find Perfect Day “in violation of the D.C. Consumer Protection Procedures Act,” and to cover their legal costs.
Attorney: ‘This is the first lawsuit I’ve seen vs precision fermented animal protein’
Rebecca Cross, founding partner at law firm Greenfare Law, told AgFunderNews: “This is the first lawsuit I’ve seen targeting a precision-fermented animal-free protein, but it’s not surprising. Any time a company challenges conventional food categories, it faces resistance from food groups tied to more traditional narratives.”
She added: “Many of the claims in this suit seem disingenuous or selectively framed. For example, Perfect Day explains on its website that genetic engineering is part of its process. And the FDA requires companies using these proteins to disclose that they contain milk proteins because they’re allergenic.
“I was really disappointed to see Kim Richman’s firm file this lawsuit. They position themselves as supporting animal welfare and going after a mission-driven company like Perfect Day, whose purpose is to reduce reliance on animal agriculture, does just the opposite.”
Perfect Day in ‘active discussions with a number of key partners’
Perfect Day—a pioneer in the animal-free dairy space—launched a series of consumer brands via its subsidiary The Urgent Company including Brave Robot Ice Cream, Modern Kitchen, and California Performance Co.
Over time, however, the business became a costly distraction for Perfect Day, which was trying to forge partnerships with large CPG companies as part of a b2b strategy and did not want to devote resources to building its own consumer brands.
In 2023, these brands were sold to a newly-created company called Superlatus, which AgFunderNews has been unable to reach for comment. Tomorrow Farms, owner of the Bored Cow animal-free milk brand (which features Perfect Day’s protein) did not respond to a request for comment on the status of the brand.
Perfect Day announced a partnership with Unilever early last year to test a lactose-free frozen dairy dessert under the Breyers brand featuring Perfect Day’s whey protein, and told us earlier this year that it is “in active discussions with a number of key partners who will serve as anchor customers for our new plant [in India].”
A spokesperson added: “We have several LOIs for product offtake with existing and new customers.”
*The case is Organic Consumers Association et al. v. Perfect Day, Inc. Case Number: 2025-CAB-000032
