Neither Enfamil nor Similac is categorically better. Both meet the same FDA nutritional standards required for all infant formulas sold in the United States, and both will safely nourish a healthy baby. The real differences show up in their ingredient strategies: Enfamil leans heavily into brain-development ingredients, while Similac focuses on gut health and immune support. Which one matters more depends on your baby’s needs, tolerance, and how they respond to each formula.
Where Enfamil Stands Out: Brain Development
Enfamil’s flagship product, NeuroPro, is built around two ingredients: DHA (an omega-3 fatty acid important for brain and eye development) and MFGM (milk fat globule membrane), a compound found naturally in breast milk. Enfamil markets these as clinically shown to support cognitive skills, with the company citing data suggesting that a year of feeding with both ingredients can produce measurable brain-development benefits through age five.
DHA is present in Similac formulas too, but Enfamil has historically included it at higher levels and made it the centerpiece of their product line. If brain development is your primary concern and your baby tolerates Enfamil well, NeuroPro is a strong option.
Where Similac Stands Out: Immune and Gut Health
Similac 360 Total Care uses an exclusive blend of five human milk oligosaccharides (HMOs), which are prebiotics structurally identical to those found in breast milk. These five specific HMOs (including 2′-fucosyllactose and lacto-N-tetraose) feed beneficial gut bacteria and support immune function. Most competing formulas include only one or two HMOs, so Similac’s blend of five is genuinely unusual in the market.
HMOs are one of the most studied components of breast milk, and they play a significant role in shaping a baby’s developing immune system and digestive tract. For babies prone to digestive issues or whose parents prioritize immune support, Similac’s HMO profile is a meaningful advantage.
The Palm Oil Difference
One of the most concrete nutritional differences between the two brands comes down to fat sources. Enfamil uses palm olein oil as a primary fat in many of its formulas. Similac does not, and this matters more than it sounds.
A review of clinical evidence published in the National Institutes of Health’s PubMed Central found that calcium and fat absorption are consistently lower in infants fed formulas containing palm olein oil compared to those without it. In one study, calcium absorption in a palm oil group was about 34%, compared to roughly 42-44% in groups using corn or sunflower oil. Another study showed fractional calcium absorption of around 57-59% with palm olein formulas versus 76% with breast milk. The pattern held across multiple trials: palm olein oil reduces how much calcium a baby actually absorbs from their formula.
Lower calcium absorption in the first year of life can affect bone mineral content. Some parents also report firmer, harder stools with palm olein-based formulas, which aligns with the reduced fat absorption the research describes. This is one area where Similac has a clear, evidence-backed edge over standard Enfamil products.
Sensitive Stomachs and Spit-Up
Both brands offer “gentle” or “sensitive” versions for babies with fussiness, gas, or mild lactose sensitivity. Enfamil Gentlease and Similac Total Care Sensitive both use partially broken-down proteins to ease digestion. In practice, some babies do better on one than the other, and there’s no reliable way to predict which without trying. If your baby is uncomfortable on a standard formula, switching to the gentle version of the same brand is a reasonable first step before jumping to the other brand entirely.
For reflux specifically, both brands make thickened formulas designed to reduce spit-up. These work similarly and the choice between them is mostly a matter of availability and your baby’s preference.
Cow’s Milk Protein Allergy
If your baby has a true cow’s milk protein allergy, you’re looking at Enfamil Nutramigen versus Similac Alimentum. Both use extensively broken-down (hydrolyzed) casein protein, and both claim colic relief within 24 hours when the colic is caused by cow’s milk protein allergy. In practice, most babies show improvement within three to five days, with full resolution of symptoms like bloody stools, skin reactions, and severe gas typically taking one to two weeks.
Nutramigen includes a probiotic strain (LGG) that some clinical research suggests may help babies develop tolerance to cow’s milk protein faster, potentially shortening the overall duration of the allergy. Alimentum does not include this probiotic. If symptoms don’t improve within two weeks on either formula, the next step is usually an amino acid-based formula like EleCare or Neocate.
Safety and Recall History
Both Enfamil and Similac have strong safety records overall, but recalls do happen in the formula industry. The most notable recent event was a 2022 recall and production shutdown at a major Similac manufacturing plant linked to bacterial contamination concerns, which contributed to a nationwide formula shortage. Enfamil was not affected by a similar large-scale recall during that period.
It’s worth noting that the most serious recent formula safety event, a 2025 infant botulism outbreak, involved a different brand entirely (ByHeart), not Enfamil or Similac. No formula brand is immune to safety issues, but both major brands have extensive quality-control infrastructure.
Price and Availability
Similac tends to be slightly less expensive per ounce than Enfamil for comparable products, though prices vary by retailer and format. Both brands are widely available at grocery stores, pharmacies, and online. Both are covered by WIC in most states, though which specific products qualify varies by state. If cost is a significant factor, store-brand formulas made by the same manufacturers often contain very similar ingredients at a lower price point.
How to Choose
Start with what your baby tolerates. A formula that your baby drinks happily, digests comfortably, and grows well on is the right formula, regardless of brand. If you’re choosing before your baby is born or before you’ve tried either, here’s a practical framework:
- Choose Enfamil NeuroPro if brain development ingredients (higher DHA, MFGM) are your priority and your baby doesn’t have digestive sensitivities.
- Choose Similac 360 Total Care if immune support (5 HMOs) and calcium absorption (no palm olein oil) matter more to you, or if your baby has harder stools on other formulas.
- For milk protein allergy, Nutramigen’s added probiotic gives it a slight edge over Alimentum, but both resolve symptoms on similar timelines.
Your pediatrician can help narrow the choice if your baby has specific risk factors, but for most healthy infants, both brands will support normal growth and development equally well.