Walk into any U.S. grocery store and you’ll see an aisle of infant formula promising peace of mind in shiny cans. Labels boast “closest to breast milk,” “for brain development,” or “trusted by pediatricians.” The marketing makes formula sound like a scientific miracle—nutritionally perfect, rigorously tested, and tightly regulated. But peel back the label, and the reality is far more unsettling.
Formula is not the carefully vetted medical product many assume it to be. It’s a highly processed food, engineered in factories, tested mainly for short-term growth, and sold in a regulatory environment that prioritizes corporate convenience over infant safety. As lactation professionals, we need to understand what’s really in the can—and why families deserve full transparency.
What’s Actually in Infant Formula?
At its core, infant formula is a synthetic approximation of human milk—engineered to keep babies alive and growing when breast milk isn’t available. But what’s actually inside the can looks far more like a chemistry experiment than the biologically active fluid produced by human breasts.
The backbone of most formulas is protein. Manufacturers start with cow’s milk proteins—whey and casein—and tinker with the ratio to look more like human milk, which is naturally whey-dominant. For babies who can’t tolerate cow’s milk, soy protein isolate becomes the base. Some formulas take it further, breaking proteins into smaller fragments (“partially hydrolyzed” or “extensively hydrolyzed”) and marketing them as easier to digest for “sensitive tummies.” In extreme cases, formulas contain no whole proteins at all, relying instead on free amino acids to feed infants with severe allergies.
Next comes the carbohydrate—essentially the sugar that fuels growth. In nature, that’s lactose. In formula, it’s often replaced or supplemented with corn syrup solids, maltodextrin, or even sucrose, especially in so-called “gentle” or “lactose-free” blends. These substitutes may solve one problem but create others: sucrose, for instance, is far sweeter than lactose and may influence taste preferences, while maltodextrin alters fermentation in the gut.
For fat, companies blend industrial vegetable oils: palm olein, soy, coconut, sunflower. To bolster the mix, they add DHA and ARA—long-chain polyunsaturated fatty acids extracted from algae or fungus—promoted as essential for brain and eye development. Whether they actually deliver on that promise is still debated.
Every can is fortified with vitamins and minerals, because U.S. law requires formulas to contain 30 essential nutrients. Iron must be included unless the label explicitly warns parents that “additional iron may be necessary.” Vitamin D is mandatory to help prevent rickets. Calcium, phosphorus, zinc, iodine, and others are added in precise amounts to satisfy legal minimums and maximums.
And then there are the “value-adds.” Companies increasingly market probiotics and prebiotics, claiming to mimic the microbial ecosystem of breastfed infants. Some add synthetic human milk oligosaccharides (HMOs), lab-created replicas of complex sugars found in breast milk. The pitch is seductive: a powder that “acts like mom’s milk.” But the reality is more modest. Studies often show only minor effects from these additives, and they cannot replicate the symphony of immune factors, hormones, and living cells present in human milk.
Formula is designed to be nutritionally complete—but its completeness is defined by law, not by nature. It can meet nutrient checklists and support growth, but it will never replicate the biological, immunological, and developmental complexity of human milk. At best, it’s an engineered substitute that fills the gap; at worst, it’s marketed as something it can never truly be.
The Assembly Line
The making of infant formula doesn’t resemble anything natural. It unfolds like an industrial recipe in a chemistry lab. Proteins, fats, and sugars are first dumped into massive stainless steel vats, where they’re churned into a uniform slurry. The mixture is then pasteurized—heated high enough to kill most bacteria—before being forced through high-pressure nozzles to homogenize the fat. This step ensures that every scoop of powder or sip of ready-to-feed formula looks and tastes the same, no matter the batch.
For powdered formulas, the liquid is then blasted into hot air and spray-dried into a fine dust, a process that strips out moisture and leaves behind the powder that parents scoop into bottles. But because the intense heat destroys fragile nutrients, manufacturers must go back and add synthetic vitamins and minerals later, restoring the legal minimums required by law. Only then is the product funneled into cans or pouches under so-called “clean room” conditions—industrial spaces designed to reduce, but never eliminate, contamination.
Here’s the unsettling truth: powdered formula is not sterile. Bacteria like Cronobacter sakazakii can survive the entire process (Centers for Disease Control and Prevention [CDC], 2024). That’s why public health authorities recommend reconstituting formula with water hot enough—at least 70°C—to kill potential pathogens. Yet this warning is rarely emphasized on formula labels, and almost never in advertising. Parents are left with the impression that what they scoop from the can is as safe as breast milk, when in reality, the powder is a product of industrial compromise.
The Illusion of Testing
Most parents assume infant formula has passed the same kind of rigorous trials as vaccines or medications before it lands on a store shelf. The reality is far less reassuring.
The only real standard U.S. law demands is that a formula supports “normal physical growth” when used as the sole source of nutrition (Infant Formula Act, 1980/2019). In practice, that means a manufacturer recruits a small group of healthy, full-term infants—often fewer than fifty. For about fifteen weeks, the babies are fed the new formula. Researchers dutifully measure weight, length, and head circumference, charting their growth curves against accepted norms. If the numbers look acceptable, the formula is considered adequate (FDA, 2022a). Adequate—not optimal. No one asks whether the babies’ immune systems mature differently, whether their brains develop on par, or whether subtle metabolic shifts set the stage for problems later in life.
Protein quality gets its own box to tick. Here the FDA requires proof that the protein source is “biologically adequate.” That proof usually comes from laboratory tests such as nitrogen balance studies or a Protein Efficiency Ratio (PER) rat bioassay—yes, a rat feeding study used as a proxy for human infants (FDA, 2023). Again, the standard is the bare minimum: show that the protein sustains growth, not that it supports thriving.
Most trials stop after just a few months. No one is required to follow those infants into toddlerhood, school age, or adolescence. The result is a gaping unknown: we know formula supports weight gain, but we don’t know what it does to allergy risk, microbiome health, obesity, or chronic disease later in life (Greer et al., 2019).
When it comes to additives like DHA, probiotics, or synthetic human milk oligosaccharides, the oversight is even looser. Companies often declare these ingredients “Generally Recognized as Safe” (GRAS), a designation typically made by expert panels chosen by the companies themselves (GAO, 2023). FDA review is limited, and long-term studies are rarely conducted before these additives hit the market.
And here’s the most unsettling point: unlike drugs, which cannot be sold until proven safe and effective through multiple phases of clinical trials, infant formulas require only 90 days’ notice to the FDA before launch. The agency can object if nutrient levels or sanitation standards are off, but it does not issue a stamp of approval (FDA, 2022a). In fact, the FDA itself states plainly that it does not approve infant formula before sale. Parents see a can wrapped in medical-sounding claims, but behind the label lies a product that’s been tested only for short-term adequacy—not for long-term safety, and certainly not for equivalence to human milk.
Why This Matters
At first glance, it might not seem like a problem that formula is only tested for short-term growth. After all, weight gain is the most visible sign of health in an infant. But growth alone is a narrow lens, and it hides the bigger story.
A baby can gain weight on formula while missing out on the protective, developmental, and immunological factors that only human milk delivers. Human milk is not just calories and protein—it is alive. It carries antibodies, hormones, stem cells, enzymes, and microbes that shape the gut and train the immune system in ways no powder ever could (Victora et al., 2016). Formula testing doesn’t even attempt to measure these differences.
The risks go deeper. Because no one studies long-term outcomes before a new formula is sold, we have no idea what the newest “innovations” really mean for infants. Synthetic human milk oligosaccharides, for example, are added because they look promising on paper. But what happens when babies consume them in isolation, stripped from the complex ecosystem of breast milk? Do they change the microbiome in ways we don’t anticipate? We don’t know—because no one is required to find out.
Even more troubling is who decides what counts as “safe.” Under the GRAS system, companies can declare their own ingredients safe, file a notice with the FDA, and start selling. Independent trials aren’t required. FDA review is minimal. Yet parents looking at the can see bold claims that make the product appear science-backed, when in reality, the science may be little more than corporate assertion (GAO, 2023).
Here’s the unfortunate truth: formula isn’t tested to prove it’s safe in the long run. It’s tested to make sure babies don’t fail to grow in the short run. Everything else—the developmental trajectory, the subtle metabolic programming, the lifelong health impact—is ignored. Families are led to believe formula is the scientific twin of breast milk. In reality, it is the nutritional baseline for survival, engineered to meet minimum standards, not maximum potential.
Conclusion
The formula industry thrives on the illusion of equivalence. Slick labels and confident marketing persuade families that what’s inside the can has been thoroughly studied, proven, and regulated with infants’ best interests at heart. But the truth is starker: formula is tested only to ensure babies gain weight in the short term—not to guarantee long-term safety, not to prove equivalence to human milk, and certainly not to safeguard infants from risk.
This matters because parents deserve honesty. They deserve to know that powdered formula isn’t sterile, that ingredient safety is often self-certified by companies, and that regulators act only after crises—not before. They deserve to know that in many countries, formula is treated like a tightly controlled medical food, while in the United States, it’s marketed like a lifestyle product.
For lactation professionals, this is not about shaming families who use formula. It’s about cutting through the smoke and mirrors of corporate messaging so that when families make decisions about feeding their babies, they do so with eyes wide open. Formula may meet the minimum bar for survival, but it will never replicate the complexity and protection of human milk. Our role is to tell the truth about what’s really inside the can.
References
Centers for Disease Control and Prevention. (2024). Cronobacter infections in infants. U.S. Department of Health and Human Services. https://www.cdc.gov/cronobacter
Food and Drug Administration. (2022a). Infant formula: Guidance for industry—Quality factors, notification, and records. U.S. Department of Health and Human Services.
Food and Drug Administration. (2022b). Guidance for industry: Infant formula enforcement discretion policy. U.S. Department of Health and Human Services.
Food and Drug Administration. (2023a). Draft guidance for industry: Protein efficiency ratio (PER) rat bioassay studies to demonstrate that a new infant formula supports the quality factor of sufficient biological quality of protein. U.S. Department of Health and Human Services.
Food and Drug Administration. (2023b). Guidance for industry: Labeling of infant formula. U.S. Department of Health and Human Services.
Food and Drug Administration. (2016/2022). Guidance for industry: Substantiation for structure/function claims made in infant formula labels and labeling. U.S. Department of Health and Human Services. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-frequently-asked-questions-about-fdas-regulation-infant-formula
Food and Drug Administration. (2022c). Guidance for industry: Frequently asked questions about FDA’s regulation of infant formula. U.S. Department of Health and Human Services. https://www.gao.gov/products/gao-10-246
Government Accountability Office. (2023). Food safety: FDA should strengthen oversight of food ingredients determined to be generally recognized as safe (GAO-23-105708). U.S. Government Publishing Office. https://www.gao.gov/products/gao-23-10570
Greer, F. R., Sicherer, S. H., Burks, A. W., & Committee on Nutrition; Section on Allergy and Immunology. (2019). The effects of early nutritional interventions on the development of atopic disease in infants and children. Pediatrics, 143(4), e20190281. https://doi.org/10.1542/peds.2019-0281
U.S. Department of Health and Human Services, Office of Inspector General. (2023). FDA’s oversight of the infant formula supply and response to contamination complaints. https://www.fda.gov/food/hfp-constituent-updates/fda-issues-updated-compliance-program-infant-formula
Victora, C. G., Bahl, R., Barros, A. J., França, G. V., Horton, S., Krasevec, J., Murch, S., Sankar, M.J., Walker, N. & Rollins, N. C. (2016). Breastfeeding in the 21st century: Epidemiology, mechanisms, and lifelong effect. The Lancet, 387(10017), 475–490.
