Switching formula alone is unlikely to cure colic, but certain formula changes can reduce crying time in some infants. Colic affects roughly 24% of babies regardless of whether they’re breastfed or formula-fed, and it resolves on its own by 3 to 4 months in most cases. The type of formula matters less than many parents hope, though a few specific changes have shown modest benefits in clinical trials.
Colic Rates Are the Same Across Feeding Types
One of the most important things to know is that formula feeding doesn’t cause colic, and breastfeeding doesn’t prevent it. A study of over 700 mothers found that 23% of exclusively breastfed babies developed colic by six weeks, compared to 21% of exclusively formula-fed babies. The difference was not statistically significant. After adjusting for other factors, the type of milk an infant received in the first week of life had no measurable effect on whether colic developed.
This matters because parents often blame themselves or their feeding choices when colic strikes. The reality is that colic appears to involve multiple overlapping factors: an immature digestive system, gut inflammation (colicky babies have higher levels of an intestinal inflammation marker called fecal calprotectin), possible lactose processing difficulties, swallowed air, and the still-developing nervous system. No single dietary fix addresses all of these at once.
What “Comfort” and Sensitive Formulas Actually Do
Many formula brands market “gentle,” “comfort,” or “sensitive” versions that use partially broken-down (hydrolyzed) milk proteins. The idea is that smaller protein fragments are easier on a baby’s gut. In a randomized controlled trial comparing a partially hydrolyzed formula with added prebiotics against a standard intact-protein formula, parents reported no difference in overall fussiness between the two groups.
There was, however, a measurable reduction in crying. Babies on the hydrolyzed formula cried less over the four-week study period, and fewer of them met the threshold for excessive crying (three or more hours per day on three or more days per week). So the picture is mixed: these formulas may take the edge off intense crying episodes without eliminating the broader pattern of fussiness and irritability that defines colic for most parents. If you’re already using a standard formula, trying a partially hydrolyzed version for two to four weeks is reasonable, but set realistic expectations.
Lactose-Free Formula and Lactase Drops
Some colicky babies struggle to fully digest lactose, the main sugar in both breast milk and most formulas. When lactose passes through the gut undigested, bacteria ferment it into gas and acid, causing bloating and cramping. This is sometimes called transient lactose intolerance because it’s temporary, tied to the immaturity of a young infant’s digestive lining rather than a permanent condition.
Two randomized, double-blind trials found that adding lactase drops (the enzyme that breaks down lactose) to milk feeds significantly reduced crying time. For formula-fed babies, the protocol involved adding drops to a small amount of warm formula, waiting 30 minutes to let the enzyme work, and then feeding. Most infants in the study showed reduced crying duration. That said, researchers noted that in bottle-fed babies specifically, swallowed air may play a larger role than lactose, which could limit how well lactase alone works.
Lactose-free formulas take a different approach by removing lactose entirely. They can help if lactose digestion is truly the main driver of your baby’s discomfort, but since colic usually involves several factors working together, removing lactose may only partially improve things.
Probiotic-Containing Formulas Show Promise
Formulas containing the probiotic strain L. reuteri DSM 17938 have some of the more convincing evidence behind them. In a cross-sectional study comparing over 1,700 infants, babies drinking formula with this probiotic cried significantly less per day than babies on standard formula without any probiotic or prebiotic. Their crying levels were statistically comparable to breastfed babies. They also spit up less often, in smaller volumes, and showed less fussiness during spit-up episodes.
The benefit appears to come from how L. reuteri interacts with the developing gut. It may reduce intestinal inflammation and improve the balance of gut bacteria, both of which are thought to contribute to colic. If you’re considering a formula change, a version containing this probiotic is one of the better-supported options.
When the Problem Might Be Milk Allergy, Not Colic
About a subset of colicky-seeming babies, the real issue is an allergy to cow’s milk protein. The symptoms overlap significantly: both conditions cause intense crying, back arching, and leg-pulling. But cow’s milk allergy typically comes with additional signs that plain colic does not. These include skin rashes (present in 20 to 25% of allergic infants), blood-streaked stools (about 6%), frequent vomiting or heavy spitting up (around 30%), and sometimes nasal congestion that mimics a cold.
European pediatric guidelines are clear that crying and irritability alone are not enough to diagnose a milk allergy. If crying is the only symptom, an elimination diet is not recommended. But if your baby has those additional red flags, or if colic persists beyond 5 to 6 months (when typical colic should have long resolved), a time-limited trial of a specialized hypoallergenic formula for two to four weeks can help determine whether cow’s milk protein is the culprit. If symptoms improve and then return when regular formula is reintroduced, allergy is likely.
Bottle Design Matters Too
Before switching formulas, it’s worth considering how your baby is drinking. Aerophagia, or swallowing air during feeding, is one of the recognized contributors to colic symptoms in bottle-fed infants. Anti-colic bottles with venting systems are designed to keep the nipple full of milk rather than air, reducing how much a baby swallows during a feed.
Clinical testing on one widely available anti-colic bottle design showed a trend toward less colic at two weeks of age compared to conventional bottles, along with a 60% reduction in nighttime fussiness compared to a leading competitor’s vented bottle. These aren’t dramatic cure-all numbers, but they’re meaningful for a problem that has no single solution. Feeding position also plays a role. Bottles that allow a baby to drink in a more upright position can reduce reflux and aid digestion.
How Long to Wait After a Formula Change
If you do switch formulas, give it at least two weeks before deciding whether it’s working. Colic symptoms naturally fluctuate from day to day, so a single good or bad day doesn’t tell you much. Keeping a simple log of crying duration over two to four weeks gives you a much clearer picture. Note the time of day, how long each episode lasts, and any other symptoms like spitting up or gas.
It also helps to change only one thing at a time. If you switch to a hydrolyzed formula and a new bottle on the same day, you won’t know which change made the difference. Start with whichever seems most relevant to your baby’s pattern. If the crying is worst right after feeds and accompanied by visible gas, addressing air intake or lactose digestion is a logical first step. If the crying is more generalized and happens regardless of feeding, a probiotic-containing formula may be a better bet.
Perhaps most importantly, colic is defined as a self-limiting condition. It peaks around six weeks of age, and in the vast majority of infants, it resolves completely by three to four months. Formula changes can make those weeks more bearable, but no formula eliminates colic entirely.