Enfamil Reguline vs ByHeart Formula (2026): Which Formula Is Better?

🍼 Two Formulas, Two Completely Different Goals

Enfamil Reguline (~$30/12.4 oz) exists for one reason: to help constipation-prone babies have softer, more comfortable bowel movements. It does this through a specific combination of prebiotics (2'-FL HMO + polydextrose/GOS blend) and partially hydrolyzed nonfat milk protein. Everything in Reguline is calibrated to promote digestive regularity.

ByHeart (~$36/24 oz) is a premium everyday formula that approaches infant nutrition differently than any other US brand. Its core innovation is a proprietary protein processing method that keeps whole milk protein closer to its natural, undenatured state. ByHeart also uses organic lactose, a fat blend containing MFGM (milk fat globule membrane), and avoids palm oil — all designed to create a formula that mimics breast milk more closely than conventional options.

• Reguline's focus: Constipation relief through dual-prebiotic fiber system and easy-to-digest hydrolyzed protein
• ByHeart's focus: Premium everyday nutrition through minimally processed whole protein, organic lactose, and MFGM-containing fat
• Protein approach: Reguline breaks protein down (partial hydrolysis) for faster absorption; ByHeart preserves protein structure (minimal processing) for more natural digestion
• Prebiotic system: Reguline includes a targeted polydextrose/GOS/HMO system; ByHeart relies on organic lactose's natural prebiotic properties

🔬 Protein Science: Hydrolyzed vs Whole

The protein philosophy is where these formulas diverge most dramatically. Reguline partially hydrolyzes its nonfat milk protein, meaning enzymes break the protein into smaller peptides before it reaches your baby. This makes it faster to digest and less likely to cause gas or bloating, but the protein loses its natural three-dimensional structure in the process.

ByHeart takes the opposite approach. Its patented processing method heats milk protein as little as possible, preserving its natural folded structure. ByHeart's research suggests that less-denatured protein is recognized by the infant gut more naturally, potentially reducing gas and spit-up while maintaining better amino acid bioavailability. Their clinical trial showed less gas, fussiness, and spit-up compared to a leading US formula.

• Reguline protein: Partially hydrolyzed nonfat milk — smaller peptide fragments that skip some digestive steps, absorbed faster but less structurally intact
• ByHeart protein: Minimally processed whole milk protein — natural structure preserved, designed to be digested the way an infant gut evolved to handle milk protein
• For constipation: Reguline's hydrolyzed protein is specifically easier on a struggling gut; ByHeart's intact protein is gentler than standard formulas but not specifically optimized for constipation
• Whey-to-casein: ByHeart maintains a breast-milk-like whey-to-casein ratio; Reguline's hydrolysis process blurs this ratio since the proteins are fragmented

🧪 Ingredient Comparison: Functional vs Premium

ByHeart's ingredient list reflects a premium formula philosophy: organic lactose (sole carb), proprietary fat blend with MFGM, no palm oil, no corn syrup, no maltodextrin. Reguline's ingredients are chosen for function over form: corn syrup solids for easy calories, palm olein for palmitic acid, and prebiotics for stool softening.

• Carbohydrate: ByHeart uses organic lactose exclusively; Reguline blends lactose with corn syrup solids
• Fat blend: ByHeart includes a proprietary blend with MFGM from milk fat (a component of breast milk linked to cognitive development); Reguline uses palm olein, coconut, soy, and sunflower oils
• Palm oil: ByHeart excludes it; Reguline contains palm olein — notable because palm oil can contribute to harder stools, the very problem Reguline is meant to solve (its prebiotics are designed to counteract this)
• MFGM: Present in ByHeart (from cream processing); not present in Reguline. MFGM contains sphingomyelin and phospholipids that support brain development and gut barrier function
• Prebiotics: Reguline has a robust dual-prebiotic system (polydextrose + GOS + 2'-FL HMO); ByHeart relies on organic lactose as a natural prebiotic without added fibers
• DHA: Both include DHA; ByHeart sources from algal oil, Reguline from standard algal/fungal oils

💰 Price, Value, and Availability

Reguline costs ~$30 for a 12.4 oz can and is available at most US retailers — Walmart, Target, Amazon, CVS, and grocery stores. ByHeart costs ~$36 for a 24 oz can, available through ByHeart.com, Amazon, Target, and select retailers. Despite the higher per-can price, ByHeart actually delivers more formula per dollar due to its larger can size.

• Per-ounce cost: Reguline is ~$2.42/oz; ByHeart is ~$1.50/oz — ByHeart is significantly cheaper per ounce despite the higher sticker price
• Monthly estimate: Reguline ~$175–210/month; ByHeart ~$150–200/month depending on intake
• Subscription: ByHeart offers a direct subscription at byheart.com with savings; Reguline is available via Amazon Subscribe & Save
• WIC coverage: Reguline may qualify with medical documentation; ByHeart is not WIC-eligible
• In-store access: Reguline has wider in-store availability; ByHeart's brick-and-mortar presence is growing but still more limited

✅ Choose Enfamil Reguline If

Reguline is a purpose-built formula for a specific digestive problem. It earns its place when constipation is the primary issue.

• Your baby has persistent constipation — hard, pellet-like stools, straining and crying during bowel movements, or bowel movements less than once every 3 days
• You've already tried a clean formula without palm oil (like ByHeart or Bobbie) and constipation persisted
• Your pediatrician recommended a prebiotic-enriched formula specifically to address stool consistency
• You need a formula available at any pharmacy or retailer today, without waiting for shipping
• You need potential WIC coverage with medical documentation

✅ Choose ByHeart If

ByHeart is the better choice when your baby doesn't have constipation and you want cutting-edge nutritional science in an everyday formula.

• Your baby doesn't have persistent constipation — digestion is normal or has mild gas/fussiness/spit-up
• You want a formula with minimally processed whole protein that preserves natural protein structure
• MFGM (milk fat globule membrane) for brain and gut development matters to you — Reguline doesn't include it
• You prefer organic lactose as the sole carbohydrate with no corn syrup solids
• You want a palm-oil-free formula — ByHeart's fat blend may naturally support softer stools
• Better per-ounce value matters — ByHeart delivers more formula per dollar than Reguline

⚖️ The Bottom Line

For most healthy babies without constipation, ByHeart is the superior formula. Its minimally processed protein, organic lactose, MFGM-enriched fat blend, and palm-oil-free formulation represent a more modern, science-driven approach to everyday infant nutrition. It also costs less per ounce than Reguline despite the higher sticker price.

Reguline is the right choice only when persistent constipation is the primary problem. Its dual-prebiotic system (polydextrose/GOS + 2'-FL HMO) actively draws water into the intestines to soften stools — a mechanism that ByHeart's formula doesn't replicate. If your baby strains painfully during most bowel movements and other formula changes haven't helped, Reguline's targeted approach justifies its specialty positioning. For everything else, ByHeart is the stronger everyday formula.