How to Switch Baby Formula Safely: A Parent’s Guide

You can usually switch your baby’s formula safely, especially when moving between comparable standard formulas. A direct change is often possible, though a gradual transition may help some babies accept a different taste. Gas, spit-up, and fussiness are common during infancy, so these behaviors do not always mean that a formula change is needed. 

Talk to your pediatrician first if you suspect an allergy or intolerance, or if your baby uses a specialized formula. This guide explains how to change formula brands safely, what to expect during the transition, and when to seek medical guidance.

Quick Answer: Can You Switch Baby Formula Safely?

The right approach depends on why you are changing formula and whether the new product serves the same general feeding need.

Situation	General approach
Switching between comparable standard formulas for cost, availability, or preference	A direct switch is often possible
Your baby resists the new taste	A gradual transition may help
Switching to a different formula type	Ask your pediatrician how to transition
You suspect an allergy or intolerance	Speak with your pediatrician before switching
Gas, spit-up, or fussiness is the only concern	First consider whether a switch is necessary
Your baby was born prematurely or has a health condition	Follow your healthcare team's instructions

Standard infant formulas sold in the United States must meet FDA requirements for nutrient content, manufacturing, and quality control. Formulas can still differ in their ingredients, taste, preparation instructions, and intended use.

How Do You Switch Baby Formula Step by Step?

For a simple change between comparable standard formulas, you can usually switch directly or introduce the new formula gradually. Before choosing either method, confirm that both products serve the same general feeding need. 

Changes involving a specialized formula, suspected allergy, prematurity, or another medical concern should follow your pediatrician’s guidance.

Step 1: Confirm Why You Are Switching

First, identify why you are switching. Cost, availability, and family preference may support a routine switch between similar standard formulas. 

Persistent symptoms, feeding difficulty, poor growth, or a suspected allergy or intolerance require pediatrician guidance.

Step 2: Check Whether the Formulas Serve the Same Feeding Need

Review both formula labels before making the change. Confirm that each product is appropriate for your baby’s age and that neither is intended for a specialized medical need.

Most healthy, full-term infants can generally switch between comparable standard infant formulas. CDC instructs caregivers to follow the container directions and use the stated water amount. 

A switch requires more caution when the new product is:

• Extensively hydrolyzed or amino acid-based
• Designed for premature babies or metabolic conditions
• Recommended for another diagnosed medical need

Do not substitute a standard formula for a specialized formula without guidance from your baby’s healthcare team.

Step 3: Decide Between a Direct and Gradual Switch

The right approach depends on the formulas involved and the reason for the change. A direct switch is often reasonable between comparable standard formulas. A slower transition may be considered if your baby resists the new taste or if your pediatrician recommends one.

Can You Switch Formula Immediately?

A direct switch may be reasonable when:

• Both products are comparable standard formulas.
• You are switching because of cost, availability, or preference.
• Your baby does not use a medically indicated formula.
• You do not suspect an allergy or intolerance.
• Your pediatrician has not recommended another approach.

To make a direct switch:

1. Prepare the new formula according to its label.
2. Offer it at your baby’s next regular feeding.
3. Follow your baby’s hunger and fullness cues.
4. Observe feeding, wet diapers, stools, and general comfort.

A different taste may affect how readily your baby accepts the new formula.

When Might a Gradual Transition Be Considered?

A gradual transition may help if your baby resists the new taste or if your pediatrician recommends a slower change. There is no standard staged mixing ratio published by US public health agencies, so do not create your own formula-mixing schedule.

If your pediatrician recommends a gradual transition, follow the specific preparation and feeding instructions they provide.

Step 4: Prepare Each Formula According to Its Own Label

Correct preparation takes priority during any formula change. Measure the required water first, then add the powder exactly as directed on the product label.

The CDC and FDA advise caregivers to use the exact amount of water and powder stated on each formula label. The FDA also recommends using the scoop supplied with the product.

Powdered infant formula is not sterile and can sometimes contain germs such as Cronobacter. For babies younger than 2 months, babies born prematurely, or babies with weakened immune systems, the CDC recommends extra precautions when preparing powdered formula. These may include preparing powdered formula with very hot water, around 158°F (70°C), to help kill germs. Ready-to-feed liquid formula is another option to discuss with your baby’s healthcare professional for infants at higher risk.

Never:

• Use one formula’s scoop to measure another formula
• Estimate partial scoops
• Add more or less water than the label directs
• Combine formula powders using preparation directions intended for only one product

If your pediatrician recommends a gradual transition involving more than one formula, follow their specific preparation and feeding instructions.

Using too much or too little water can change the concentration of nutrients and fluids your baby receives.

For more bottle-preparation guidance, see All of Your Formula Prep Questions Answered. 

Step 5: Change One Feeding Variable at a Time

Keep the rest of your feeding routine consistent when possible. Continue using the same bottle, nipple flow, feeding position, and general schedule during the transition.

Changing several feeding variables at once can make it harder to identify what affected your baby’s feeding behavior. A nipple with a different flow rate, for instance, may affect feeding comfort or spit-up independently of the formula.

Keep standard bottle-feeding safety practices the same during the transition. The CDC advises caregivers to hold the bottle during feeds, never prop it, and never put a baby to bed with a bottle. Bottle propping can increase the risk of choking, ear infections, and tooth decay.

Step 6: Watch the Overall Feeding Pattern

One bottle does not show how your baby will respond to a new formula. Look at the overall feeding and hydration pattern.

Pay attention to:

• Willingness to feed
• Usual feeding amount
• Wet diaper patterns
• Stool consistency
• Spit-up
• Comfort during and after feeds
• Alertness during normal awake periods

Minor changes do not automatically mean the switch has failed. Contact your pediatrician if your baby feeds poorly, has fewer wet diapers, develops worsening symptoms, or appears unwell.

When Should You Switch Your Baby’s Formula, and When Should You Not?

A formula switch may be reasonable because of cost, availability, family preference, or pediatrician advice. A diagnosed allergy, intolerance, or medical feeding need may also require a different formula, but the new product should be selected with your baby’s healthcare professional.

When Might a Formula Switch Be Unnecessary?

Gas, small spit-ups, crying, and unsettled periods do not automatically mean that your baby is sensitive to formula. These behaviors are common during infancy and can occur as the digestive system develops.

The American Academy of Pediatrics states that switching formulas for frequent crying, spit-up, or gas is rarely helpful. Small spit-ups can also occur because babies have small stomachs or swallow air during feeding.

For broader feeding guidance, Munchkin’s Feeding Without Frustration episode features pediatrician and board-certified lactation consultant Dr. Mona Amin discussing common feeding challenges from breastfeeding through the toddler years. 

The episode offers practical, evidence-based reassurance for parents managing feeding changes and concerns.

Can You Switch Formula Brands Safely?

Most healthy, full-term babies can move between comparable standard formulas without a lengthy transition. HealthyChildren states that switching from one milk-based formula to another is not harmful, although changing formulas is rarely helpful for frequent crying, spit-up, or gas.

Products may still differ in taste, protein composition, carbohydrate source, fat blend, and added ingredients. These differences may affect how readily your baby accepts the taste or may temporarily change stool patterns.

What Is the Difference Between Switching Brands and Switching Formula Types?

A brand switch usually means moving between two formulas designed for the same general feeding need. A formula-type switch may change the protein source, degree of protein breakdown, carbohydrate source, or medical purpose.

The distinction affects how carefully the change should be managed.

Type of switch	Example	General approach
Comparable brand switch	One comparable standard cow's milk-based formula to another	A direct or gradual switch may be possible
Formula-type switch	Standard formula to extensively hydrolyzed formula	Ask your pediatrician how to transition
Specialized formula switch	Premature, amino acid-based, or metabolic formula change	Follow your healthcare team's instructions

A change between comparable standard formulas is usually simpler than a move to a specialized product. Speak with your pediatrician before changing formula types because specialized formulas are intended for particular nutritional or medical needs.

What Should You Expect After Switching Formula?

A different taste may affect how readily your baby accepts the new formula. You may also notice temporary changes in stool color, smell, frequency, or consistency. Gas and spit-up patterns may change as well. These differences do not automatically mean that the new formula is unsuitable.

Minor changes may settle over several days. For a routine switch between comparable standard formulas, assess the overall feeding pattern rather than relying on a fixed timeline.

Do not wait through an adjustment period if symptoms worsen or affect feeding, hydration, breathing, or alertness.

The transition is generally going well when your baby:

• Continues feeding regularly
• Has their usual wet diaper pattern
• Remains alert during normal awake periods
• Passes stools without ongoing difficulty

Contact your pediatrician if your baby has:

• Poor or declining intake
• Fewer wet diapers
• Repeated forceful vomiting
• Blood in the stool
• Persistent watery or hard stools
• Unusual sleepiness

For more details on stool color, consistency, and frequency after a formula change, read Formula-Fed Baby Poop: What Is Normal?. If you are concerned that your baby may be reacting to the new formula, review Signs Your Baby May Be Sensitive to Formula.

How Should You Switch Formula for a Suspected Allergy or Intolerance?

Do not diagnose or treat a suspected allergy or intolerance by switching formulas on your own. Speak with your baby’s pediatrician before choosing a specialized formula.

Cow’s milk protein allergy and lactose intolerance are not the same condition. A milk allergy involves an immune reaction to milk protein. Lactose intolerance involves difficulty digesting lactose, the natural sugar in milk. A lactose-free cow’s milk-based formula may still contain cow’s milk protein, so it is not automatically suitable for a baby with a milk protein allergy.

If cow’s milk protein allergy is confirmed, your pediatrician may recommend an extensively hydrolyzed or amino acid-based formula, depending on your baby’s needs.

Can You Switch to Goat Milk Formula for Cow’s Milk Protein Allergy?

Goat milk formula is not an appropriate alternative for a baby with cow’s milk protein allergy. Cow’s milk and goat milk contain similar proteins, so a baby may react to both. The American Academy of Pediatrics advises against using goat milk or other mammalian milk formulas for babies who are allergic to cow’s milk formula.

For a broader comparison of protein sources, digestion, and suitability, check out Goat Milk Formula vs. Cow Milk Formula.

When Should You Call Your Baby’s Pediatrician?

Contact your baby’s pediatrician before switching formula if you suspect an allergy or intolerance, your baby was born prematurely, or your baby uses a specialized formula. You should also call if feeding, hydration, or behavior worsens after the change.

Seek urgent medical care if your baby develops:

• Trouble breathing or swallowing
• Swelling of the face, lips, mouth, or tongue
• Widespread hives with another symptom
• Repeated forceful vomiting
• Unusual limpness or difficulty waking
• Signs of serious dehydration

“Minor changes in taste preference, stool pattern, gas, or spit-up can happen after a formula change. Focus on your baby’s overall feeding, wet diapers, alertness, and comfort, and contact your pediatrician if you notice persistent or concerning changes."

- Dayna Landry, MS, MPH, RD

Do not wait for these symptoms to resolve as part of a normal adjustment period.

Considering a Standard Infant Formula?

If you are switching between standard formulas for a nonmedical reason, such as availability, cost, or family preference, Munchkin Infant Formula is an iron-fortified, cow’s milk-based option for infants from birth through 12 months, with lactose as its primary carbohydrate.

For help comparing standard formula types and ingredients, see How to Choose a Baby Formula and What Is Baby Formula Made Of?

Frequently Asked Questions

Can You Mix Two Different Formulas in the Same Bottle?

Do not create your own formula-mixing ratio. If your pediatrician recommends using both formulas during a transition, follow their specific instructions, if one has been provided, and prepare each product exactly as directed on its label.

Can You Use the Old Formula Scoop With the New Formula?

No. Scoop sizes and preparation ratios may differ between products. Use the scoop packaged with each formula and follow the instructions on that container.

What Should You Do If Your Baby Refuses the New Formula?

Do not force your baby to finish the bottle. Confirm that the formula was prepared correctly and that the nipple flow has not changed. A gradual transition may help when the formulas serve the same feeding need. Contact your pediatrician if refusal affects intake or leads to fewer wet diapers.

Can You Switch Back to the Previous Formula?

You can usually return to a previously tolerated standard formula when the original switch was made for cost, availability, or preference. Speak with your pediatrician before switching back if the change involved an allergy, specialized formula, prematurity, or another medical need.

This article is for general informational and educational purposes only and is not intended as medical advice. Many of the symptoms that lead parents to consider switching formula are common and not necessarily caused by the formula. Do not diagnose an allergy or intolerance, or switch to a specialized formula, on your own; talk to your pediatrician, especially if your baby was born prematurely or has any health condition. Breastfeeding is recommended as the best source of nutrition for most infants.

References

• American Academy of Pediatrics, HealthyChildren.org, Why Babies Spit Up - https://www.healthychildren.org/English/ages-stages/baby/feeding-nutrition/Pages/Why-Babies-Spit-Up.aspx
• U.S. Food and Drug Administration, Infant Formula Homepage - https://www.fda.gov/food/resources-you-food/infant-formula-homepage
• Centers for Disease Control and Prevention, Infant Formula Preparation and Storage - https://www.cdc.gov/infant-toddler-nutrition/formula-feeding/preparation-and-storage.html
• U.S. Food and Drug Administration, Infant Formula: Safety Do’s and Don’ts - https://www.fda.gov/consumers/consumer-updates/infant-formula-safety-dos-and-donts
• American Academy of Pediatrics, HealthyChildren.org, Bottle-Feeding (Formula) Questions - https://www.healthychildren.org/English/tips-tools/symptom-checker/Pages/symptomviewer.aspx?symptom=Bottle-Feeding+(Formula)+Questions
• American Academy of Pediatrics, HealthyChildren.org, What Should I Know About Recalled Baby Formula? - https://www.healthychildren.org/English/tips-tools/ask-the-pediatrician/Pages/What-should-I-know-about-the-infant-formula-recall.aspx
• American Academy of Pediatrics, HealthyChildren.org, Gastroesophageal Reflux and Gastroesophageal Reflux Disease - https://www.healthychildren.org/English/health-issues/conditions/abdominal/Pages/GERD-Reflux.aspx
• American Academy of Pediatrics, HealthyChildren.org, Choosing a Baby Formula - https://www.healthychildren.org/English/ages-stages/baby/formula-feeding/Pages/choosing-an-infant-formula.aspx
• American Academy of Pediatrics, HealthyChildren.org, Hives in Children: Causes, Symptoms and Treatment - https://www.healthychildren.org/English/health-issues/conditions/skin/Pages/hives.aspx
• American Academy of Pediatrics, HealthyChildren.org, Hypertrophic Pyloric Stenosis: Help for Babies With Forceful Vomiting - https://www.healthychildren.org/English/health-issues/conditions/abdominal/Pages/Hypertrophic-Pyloric-Stenosis-HPS-Babies-Forceful-Vomiting.aspx
• Children’s Hospital of Philadelphia, Cow-milk Formula vs. Goat-milk Formula - https://www.chop.edu/pediatric-health-chat/cow-milk-versus-goat-milk-formula
• Centers for Disease Control and Prevention, Preventing Cronobacter in Infants - https://www.cdc.gov/cronobacter/prevention/index.html