Whatever the reason your baby is receiving formula, you can relax: infant formula is safe, nutritious, and tightly regulated. It's designed to resemble breast milk as closely as possible, and covers all of your baby's nutritional needs in the first year of life.

This guide gives you an overview of types, preparation, and guidelines from leading health authorities — so you can feel confident in the choices you make for your child.

What Is Baby Formula?

Baby formula is an industrially produced milk mixture that can be given to infants as a substitute for, or supplement to, breast milk. It is sold in grocery stores and pharmacies in both powder and ready-to-feed form.

According to the WHO, infant formula is made to have approximately the same nutritional content as breast milk. All products sold in regulated markets must meet strict requirements for composition and labeling, enforced by authorities such as the FDA in the United States.

Three Main Types

Standard cow's milk-based: The most common type. Suitable for the vast majority of babies. Products labeled "Stage 1" are designed from birth
Follow-on formula (Stage 2, 3, or 4): For older babies. Children under six months should not have follow-on formula
Specialized (hydrolyzed): For babies with confirmed cow's milk protein allergy, only on medical recommendation

Soy-based and goat's milk-based formulas are also available. Soy-based formula should not be given to premature babies, according to the AAP.

Never make homemade formula from regular milk, goat's milk, or plant-based drinks. According to the WHO and AAP, incorrect composition can damage a baby's kidneys and lead to serious malnutrition.

When to Use Baby Formula?

There are many reasons families use formula. Some combine it with breastfeeding, others use it as the sole source of nutrition. Both approaches are completely fine.

Common Situations

Supplement to breastfeeding: When breast milk supply doesn't meet needs, or mom needs a break
Full replacement: When breastfeeding is not possible or desired
Medical need: With illness in mom or baby, medications incompatible with breastfeeding, or premature birth
After weaning: When the family is ready to stop breastfeeding

Combining breastfeeding and bottle? Offer breast milk first, then formula. It's beneficial to offer the breast first so that milk production is maintained.

Health Authority Guidelines

The WHO and AAP recommend exclusive breastfeeding for the first six months when possible. But they are clear: if the baby is not receiving breast milk, infant formula is the safe alternative.

For the first four to six months, breast milk or formula should be the only thing the baby has — no other food or drink. After around four to six months, introducing solid foods can begin gradually.

Vitamin D

Breastfed babies need vitamin D drops from approximately one week of age. Babies who receive only formula do not need extra vitamin D, as it is already added to the formula. Check with your pediatrician for specific guidance.

Choosing the Right Formula

Most babies do well with standard cow's milk-based formula. You don't need the most expensive option — all approved products meet regulatory requirements.

Standard Cow's Milk-Based

Suitable for the vast majority of babies. You can use Stage 1 formula throughout the entire first year. There are many brands available, and all approved options are safe choices.

For Allergies — Only on Medical Recommendation

Health authority guidelines are clear on this:

Partially hydrolyzed (HA): Not recommended for allergy prevention, even for high-risk children. Research does not show a preventive effect — the AAP and WHO advise against this
Fully hydrolyzed: Only for confirmed cow's milk protein allergy, in consultation with a doctor
Soy-based: May be chosen by vegan families, but speak with your pediatrician first

Children with a strong family history of allergies can still receive standard formula. The AAP states that standard formula is safe even for children at high risk of allergy.

Lactose Intolerance

Lactose intolerance is very rare in children under one year, even in children whose parents come from populations where the condition is common. Standard formula can be used.

Preparation — Step by Step

Good hygiene and correct temperature are essential to prevent your baby from getting sick. Powdered formula is not a sterile product and may contain bacteria.

How to Do It

Wash your hands thoroughly with soap and water
Sterilize bottles and equipment — bottles should be sterilized as long as the baby is bottle-fed. A sterilizer can also be used
Boil fresh cold tap water that has been running for a moment
Pour the water into the sterilized bottle — the water must be at least 70°C (158°F) when the powder is mixed in
Add the exact amount of powder with the measuring scoop. Fill loosely and level off with a knife
Shake gently so the formula reaches an even temperature throughout
Cool quickly under running cold water or in an ice bath — takes about 2 minutes
Test the temperature by dripping a few drops on the inside of your wrist. It should feel lukewarm (37°C / 98.6°F)

Manufacturer packaging often states 40–50°C, but the WHO recommends at least 70°C (158°F). This temperature kills bacteria that may be present in the powder. Always cool thoroughly before the baby drinks.

Amount per Feed

The amount increases with the baby's age. Here is a general guide:

1–2 weeks: approx. 70 ml (2.4 oz) per feed, 7–8 feeds
3–4 weeks: approx. 100 ml (3.4 oz), 5–7 feeds
1–2 months: approx. 135 ml (4.6 oz), 5–6 feeds
3–4 months: approx. 170 ml (5.8 oz), 5 feeds
5–6 months: approx. 200 ml (6.8 oz), 4–5 feeds

Follow the instructions on the packaging and speak with your pediatrician about your baby's weight gain.

Storage and Shelf Life

Correct storage prevents bacterial growth and keeps the formula safe.

Prepared formula in the refrigerator: Safe for up to 24 hours at a maximum of 4°C (39°F)
At room temperature: Use within 2 hours, then discard
On the go in a cooler bag: Use within 2 hours. For longer outings — bring powder and hot water in a thermos
Unopened powder: Store in a cool, dry place; check the expiry date
Opened powder: Follow the manufacturer's instructions, usually 3–4 weeks
Ready-to-feed carton: Sterile product, convenient for travel

You can prepare formula for the whole day in a large glass or stainless steel container. Cool quickly, divide into bottles, and store in the refrigerator. Discard anything unused after 24 hours.

Transitioning from Breastfeeding to Bottle

The transition doesn't need to happen abruptly. Many families combine breastfeeding and bottle feeding over time.

Practical Tips

Start with one bottle feed per day and increase gradually over 1–2 weeks
Have another caregiver offer the bottle the first few times, so the baby doesn't expect the breast
Try different nipple shapes — some babies are particular about the form
Hold the baby close to your body for warmth and security, just as with breastfeeding
Be patient — it's completely normal for the baby to need time to get used to a bottle

Thinking about stopping breastfeeding entirely? Read our guide on weaning from breastfeeding for a safe and gradual transition.

Struggling with breastfeeding and considering alternatives? We also have guides on breastfeeding positions and breastfeeding challenges.

Cost and Availability

Infant formula is available at grocery stores, pharmacies, and online retailers. You do not need a prescription for standard formula.

Standard powdered formula: Typically ranges from $20–$35 per can (lasting approximately 3–5 days for a newborn)
Ready-to-feed: More expensive per feed, but convenient for travel and night feeds
Hydrolyzed (specialty nutrition): Significantly more expensive. Speak with your doctor about possible insurance coverage or medical expense assistance programs

The monthly cost for a baby receiving only formula is typically $100–$200, depending on brand and the baby's age.

Use Babysential's SmartStart meal planner to keep track of your baby's feeds and amounts — whether you're breastfeeding, bottle-feeding, or combining.

You're Doing a Great Job

Let's say it plainly: there is no reason to feel guilty about giving your baby formula. The "breast is best" message can feel like pressure, but the most important thing is that your baby is fed, safe, and loved.

Formula is a safe, nutritious, and rigorously regulated product. Millions of children worldwide grow up on formula and develop perfectly well. Whatever your reason — medical, practical, or personal — your choice is valid.

The AAP itself says it: health professionals should adapt advice to each individual child and family. That means what works best for your family is the right choice.

Frequently Asked Questions

Can I switch between different formula brands?

Yes. All approved products meet the same nutritional requirements. Most babies tolerate switching brands without problems. Do it gradually if you're unsure.

Does my baby need water in addition to formula?

No, not for the first six months. Formula covers your baby's fluid needs. After the baby starts solid foods, you can offer a little water at mealtimes.

Is it safe to warm formula in the microwave?

The WHO advises against this. Microwaves can create uneven heating with "hot spots" that can burn your baby. Instead, warm the bottle in a water bath or under running warm water.

How long should my baby have formula?

Formula is recommended throughout the entire first year. From 12 months, the baby can gradually transition to regular whole milk, maximum about 16 oz (500 ml) per day including yogurt.

Can my baby have formula and breast milk at the same time?

Absolutely. Many families combine breastfeeding and bottle feeding. This is called mixed feeding and is completely safe. Offer breast milk first and formula after to help maintain milk production.

What's the difference between Stage 1 and Stage 2 formula?

Stage 1 formula is designed from birth and can be used throughout the entire first year. Stage 2 (follow-on formula) is designed for babies over six months and has a slightly different composition. It's completely fine to continue with Stage 1 all year — you don't need to switch to Stage 2.

Can my baby react to the formula?

Some babies may experience an unsettled stomach, more gas, or constipation when starting formula. Allow 1–2 weeks for adjustment. If the baby has ongoing problems, check with your pediatrician. Avoid switching frequently between brands.

How hot should the water actually be?

The WHO recommends that the water be at least 70°C (158°F) when the powder is mixed in. This temperature kills any bacteria that may be present in the powder. Always cool thoroughly to 37°C (98.6°F) — body temperature — before the baby drinks.

Comparison of Formula Types

Type	Suitable for	Contents	Availability
Standard cow's milk-based (Stage 1)	Most babies from birth	Matched to breast milk composition, with added vitamin D and iron	Grocery stores and pharmacies
Follow-on formula (Stage 2)	Babies over 6 months	Slightly more iron, possibly different fat content	Grocery stores and pharmacies
Partially hydrolyzed (HA)	Not recommended by WHO/AAP	Partially broken-down protein	Pharmacies
Fully hydrolyzed	Confirmed cow's milk protein allergy	Protein fully broken down	Pharmacies, doctor-prescribed
Amino acid-based	Severe cow's milk protein allergy	Free amino acids, no protein	Pharmacies, doctor-prescribed
Soy-based	Vegan families (after consultation)	Soy protein, not for premature babies	Pharmacies
Goat's milk-based	Alternative to cow's milk	Goat milk protein	Grocery stores and pharmacies

The AAP and WHO do NOT recommend partially hydrolyzed formula (HA types) to prevent allergy. Research does not show a preventive effect. Children at high risk of allergy can safely use standard cow's milk-based formula.

Sources and References

Last updated: March 2026

Baby Formula: Everything You Need to Know