Nonfat milk Straight cow milk is great for lil’ Bessie, but not for little Bradley. Human newborns can’t use that particular fat efficiently: Up to 50 percent goes right through them. What’s more, bovine proteins can wreak havoc in the infant gut, leading to allergies. Heat-treating these proteins is the first step in turning cow milk into faux human milk.
Lactose Human milk contains more natural sugar than cow milk. To sweeten the deal, formula makers add extra lactose, which breaks down into the simpler carbohydrates glucose and galactose.
Palm olein oil Palmitic acid makes up 20 to 24 percent of the fat in human milk, so Enfamil supplements its formula with palm olein oil. The slightly different arrangement of triglycerides causes constipation in many formula-fed babies. Palm olein also tends to produce the infamous yellow poop.
Mortierella alpina oil Extracted from Mortierella fungus, this oil supplies arachidonic acid. Bodybuilders use AA to bulk up their muscles. Infants use it to bulk up their neurons, because AA is the principal omega-6 fatty acid in the brain. It’s also a precursor of eicosanoids, hormones that play a role in numerous functions, including blood clotting.
Nucleotides When cells are damaged, they can release these compounds, cueing the immune system to start cleaning house. Adding them to infant formula jump-starts a baby’s antibody response to immunization. Plus, they may help put the kid to sleep.
Ferrous sulfate FeSO4 is among the best-absorbed iron compounds, but it has to be balanced precisely: Too much leads to the infamous green poop.
L-carnitine In adults, this nutrient shows potential to treat heart conditions and boost sperm count. In babies, it helps metabolize fats.
Crypthecodinium cohnii oil This oil is rich in docosahexaenoic acid, which until recently US infant formulas lacked. The long-chain fatty acid is essential to eyesight development and seems to increase information processing in infants.
Inositol It’s an enzyme activator, a cell growth factor, and a component of cell membranes. Breast milk is loaded with the stuff, so it makes sense to put inositol in formula. But studies of premies show that the formula version doesn’t last as long in the bloodstream.
Novelist Stephen King, writing as a book reviewer for the July 11, 2003 Entertainment Weekly, noted the success of any novel due to a great villain, with Professor Umbridge the "greatest make-believe villain to come along since Hannibal Lecter."
Camphor Originally derived from a type of laurel tree (Cinnamomum camphora), this waxy aromatic substance has been used as a drug since the Middle Ages. It’s absorbed quickly through the skin, where it activates the TRPV3 and TRPV1 nerve receptors, creating a cooling sensation followed by an analgesic—local anesthetic—effect. Camphor is also the active ingredient in Vicks VapoRub and some pest repellents—insects detest the smell. Nowadays, it’s synthesized from turpentine oil.
Menthol An extract of peppermint oil, menthol is often called peppermint camphor because the effects of the two are so similar (menthol triggers the TRPM8 nerve receptors). It adds a bracing, albeit fake, freshness to thousands of products, from cigarettes to mouthwashes to sunburn ointments.
Methyl Salicylate Another mild analgesic, this is synthesized oil of wintergreen. It also happens to be a cousin of aspirin, and it’s the spark-in-the-dark stuff in Wint-O-Green Life Savers. The substance’s dirty little secret? It’s toxic: Excessive use of topical methyl salicylate creams can be fatal, especially for teenagers, whose livers can’t break it down quickly.
Carbomer 940 This clear thickening agent is made from cross-linked polymers of acrylic acid (the stuff in Plexiglas and floor polish). In gel form, it’s used in hair styling products, and versions of it are present in “blue ice” cold packs. Ingestion or inhalation is hazardous, so don’t Bengay a sore tongue.
Polysorbate 80 A favorite food of Zippy the Pinhead, polysorbate 80 is used in Bengay as an emulsifier, keeping the ingredients mixed. In other contexts, it’s believed (by very desperate people) to halt hair loss by stripping away dihydrotestosterone from your scalp’s hair follicles. There’s somewhat stronger evidence that it causes infertility in rats—when lab technicians inject it directly into their little bodies.
Edetate Disodium In the event of a calcium or digitalis overdose, this microcrystalline powder can be injected as an emergency measure to restore the body’s calcium balance or heart rate. Here it acts as a preservative and stabilizer, preventing outside impurities from spoiling the contents.
Lanolin Purified wool grease (lana is Latin for “wool”). Lanolin is secreted by the sebaceous glands of sheep and goats, waterproofing their coats. It’s mostly cholesterol (lab-grade cholesterol is derived from lanolin) and other fatty acids, and it’s used in topical products like Bengay to prevent the skin from drying out. Ever shaken hands with a shepherd? Sssoffft.
Potassium Hydroxide Also known as caustic potash or lye. Naturally derived from wood ash, KOH is used to make liquid soaps and provides the “alkaline” in alkaline batteries. Concentrated KOH reacts violently with water (giving off tremendous heat) and with metals like zinc and copper (emitting potentially explosive hydrogen gas). Here it’s just a humble emulsion stabilizer—ensuring all the ingredients mingle properly.