Enfamil Reguline vs Gerber Good Start SoothePro (2026): Which Formula Is Better?

Constipation vs Colic: Two Different Problems, Two Different Formulas

Enfamil Reguline and Gerber Good Start SoothePro are both specialty formulas, but they solve fundamentally different digestive issues. Reguline is built around a dual-prebiotic system designed to produce soft, comfortable stools. SoothePro uses partially hydrolyzed whey protein and the probiotic L. reuteri to calm colic, reduce gas, and ease fussiness. Choosing between them depends entirely on which GI symptom your baby is actually experiencing.

• Enfamil Reguline: ~$30/12.4 oz — designed specifically for constipation with a dual-prebiotic blend of polydextrose and galactooligosaccharides (GOS)
• Gerber Good Start SoothePro: ~$32/12.4 oz — designed for colic and fussiness with 100% partially hydrolyzed whey protein and L. reuteri probiotic
• Both are milk-based, iron-fortified, and nutritionally complete for infants 0-12 months
• Neither is hypoallergenic — babies with confirmed cow's milk protein allergy need a different formula entirely
• Both are widely available at Target, Walmart, Amazon, and major pharmacies

Ingredient Breakdown: What's Actually Inside

The ingredient profiles reveal how differently these formulas approach infant digestion. Reguline's standout feature is its prebiotic fiber blend — polydextrose and GOS work together to draw water into the intestines and feed beneficial gut bacteria, producing softer stools naturally. The protein is a standard nonfat milk and whey protein concentrate blend. SoothePro's defining ingredient is its 100% partially hydrolyzed whey protein, which breaks casein out of the equation entirely. Smaller protein fragments are easier for immature guts to process, reducing the fermentation that causes gas and colic symptoms.

• Reguline protein: nonfat milk + whey protein concentrate (60:40 whey-to-casein) — standard intact proteins, not hydrolyzed
• SoothePro protein: 100% partially hydrolyzed whey — no casein, proteins pre-broken into smaller peptides for easier digestion
• Reguline prebiotics: polydextrose + GOS — clinically shown to promote softer stools within days of use
• SoothePro probiotic: L. reuteri — a well-studied strain shown to reduce crying time in colicky infants by up to 50% in clinical trials
• Fat blend: both use palm olein, soy, coconut, and high oleic sunflower oils. Reguline also includes DHA and ARA from single-cell sources
• Carbohydrate: both use lactose as the primary carb, plus corn maltodextrin. SoothePro includes a small amount of corn syrup solids

Nutritional Comparison Per 5 fl oz Serving

Both formulas meet FDA requirements for infant nutrition and deliver 20 calories per fluid ounce. The macronutrient profiles are nearly identical, with the key differences being in the type of protein and the prebiotic/probiotic additions rather than raw nutrition numbers.

• Calories: Reguline 100 kcal vs SoothePro 100 kcal — identical energy density
• Protein: Reguline 2.1g (intact whey/casein) vs SoothePro 2.2g (hydrolyzed whey only)
• Fat: Reguline 5.3g vs SoothePro 5.1g — both include DHA and ARA for brain development
• Carbohydrate: Reguline 11.0g (lactose + maltodextrin) vs SoothePro 10.9g (lactose + maltodextrin + corn syrup solids)
• Iron: both provide approximately 1.8 mg per serving, meeting the AAP recommendation for iron-fortified formula
• DHA: Reguline 17 mg vs SoothePro 16 mg per serving — negligible difference

How Each Formula Works: Mechanism of Action

Reguline's dual-prebiotic approach works osmotically and biologically. Polydextrose is a soluble fiber that draws water into the intestinal lumen, making stools softer and easier to pass. GOS feeds beneficial Bifidobacteria in the colon, which produce short-chain fatty acids that further promote healthy motility. Most parents report softer stools within 2-4 days of starting Reguline.

SoothePro attacks colic from two angles. The partially hydrolyzed whey protein is pre-broken into smaller peptides, reducing the digestive workload on the baby's immature gut and producing less gas during fermentation. The L. reuteri probiotic colonizes the intestinal lining and has been shown in multiple randomized trials to reduce daily crying time by 50+ minutes in colicky infants. Results typically appear within 1-2 weeks.

• Reguline: prebiotic fibers soften stool + promote beneficial gut bacteria growth — addresses the root cause of formula-related constipation
• SoothePro: hydrolyzed protein reduces gas production + L. reuteri calms intestinal inflammation — addresses the root cause of colic
• Neither formula works as a crossover solution — Reguline won't fix colic, and SoothePro won't reliably soften hard stools

Taste, Mixing, and Practical Feeding Considerations

From a day-to-day feeding perspective, both formulas are powder-based and mix with water. Reguline dissolves easily and has a mild, slightly sweet taste that most babies accept without resistance. SoothePro can have a slightly bitter edge due to the hydrolyzed protein — this is common with all comfort/hydrolyzed formulas and some babies need a gradual transition period to accept the taste.

• Reguline mixes smoothly with minimal clumping — standard powder scoop measures 8.7g for 2 fl oz of water
• SoothePro produces a slightly frothier mixture — let the bottle sit for a minute after shaking to reduce air bubbles that can worsen gas
• SoothePro's hydrolyzed protein may cause a slight sulfur smell in stools, which is normal and not a sign of intolerance
• Reguline stools tend to be softer and more frequent — expect 2-4 soft bowel movements per day once established
• Both formulas should be used within one month of opening the can and prepared bottles should be used within one hour or refrigerated for up to 24 hours

Price and Availability Comparison

Both formulas are priced in the specialty formula range, costing more than standard Enfamil or Gerber options. The price difference between them is minimal, so cost shouldn't drive the decision — symptom matching should.

• Enfamil Reguline: ~$30 for 12.4 oz (approximately $2.42/oz) — available at Walmart, Target, Amazon, CVS, Walgreens
• Gerber Good Start SoothePro: ~$32 for 12.4 oz (approximately $2.58/oz) — same retailer availability plus many grocery stores
• Both are available through Amazon Subscribe & Save for 5-15% off recurring orders
• No generic or store-brand equivalent exists for either formula — their specialty prebiotic/probiotic blends are proprietary
• Monthly cost at typical newborn intake (25 oz/day): Reguline ~$180/month vs SoothePro ~$195/month

The Verdict: Match the Formula to the Symptom

This comparison isn't about which formula is "better" overall — it's about which one matches your baby's specific digestive issue. Reguline and SoothePro are both well-designed specialty formulas, but they target completely different problems.

• Choose Enfamil Reguline if: your baby has hard, infrequent, or pellet-like stools, strains visibly during bowel movements, or has been diagnosed with formula-related constipation
• Choose Gerber SoothePro if: your baby has excessive crying, visible gas, a distended belly, or has been diagnosed with colic or general fussiness after feeding
• If symptoms overlap or you're unsure: consult your pediatrician for a specific diagnosis before choosing a specialty formula
• Give either formula a full 1-2 week trial before judging effectiveness — specialty formulas need time to produce measurable results
• Neither formula is intended for babies with confirmed cow's milk protein allergy — those babies need an extensively hydrolyzed or amino acid-based formula