For some newborns, thickened formula can be an important part of a healthy feeding plan. Parents who are pumping breast milk can also add thickeners to baby’s bottles. Whether your baby is experiencing reflux, swallowing difficulties, or other medical concerns, your pediatrician or feeding specialist may recommend using thickeners to help your little one feed more safely and comfortably.

As parents and caregivers, it’s natural to have questions: Will thickened formula work with my baby’s bottle? How will it impact baby’s feeding time? What’s the best way to prepare for a thickened feed?

At mōmi, we’re committed to supporting feeding journeys with high-quality tools and transparent guidance. That’s why we tested how different types of thickened formula impact flow rate using our nipples—and prepared this advice for how parents can adjust bottle preparation to help ensure smooth, stress-free feedings.

why some babies need thickeners

Thickened formulas, or the incorporation of thickeners into pumped milk, are often recommended for babies with:

• Reflux (GER or GERD): Thicker consistency helps formula stay in the stomach, reducing spit-up.
• Swallowing or aspiration concerns (such as infant dysphagia): Thickened feeds can help babies coordinate swallowing more safely and reduce the risk of formula entering the airway.
• Poor weight gain or feeding fatigue: Some babies benefit from slowed flow to manage suck-swallow-breathe patterns more effectively.

If your baby’s healthcare provider has advised using thickened feeds, you're not alone—and you’re making an important choice to support your baby’s health.

how to thicken bottle feeds

There are a variety of widely available thickening agents. (Always consult with your baby’s pediatrician or feeding specialist if you have questions about the safety of a thickening product.) 

Options include:

• rice cereal (not considered a viable thickener for breast milk, as the enzymes naturally present in the milk break down the rice starch)
• starch-based thickeners
• locust bean gum or carob bean
• gum alginate thickeners, which are derived from seaweed and thicken in baby’s stomach (most often recommended for reducing the symptoms and severity of infant reflux)
• commercial products like Gelmix and SimplyThick.

will thickener clog the nipple?

Here’s what we learned about formula thickness and mōmi nipple flow. To help families navigate bottle feeding with confidence, we tested how both regular and thickened formulas affect the flow of milk through mōmi bottle nipples. Here’s what we found:

regular formula:

Similac Advance Ready-to-Feed Liquid: Flows easily through mōmi nipples at the expected level, with no change to the expected flow rate.

all thickened formulas slow the flow:

Even when using a higher-flow nipple (like L2 or L3), thickened formulas reduce the rate of milk flow. The amount of reduction depends on the thickener used.

• Enfamil AR (liquid or powder): Decreases flow by about ½ level.
• Similac Advance Ready-to-Feed + SimplyThick (liquid) or GelMix (powder): Decreases flow by 1 full level.
• Similac Advance Ready-to-Feed + Gerber Rice Cereal (using 2 tsp per ounce): Decreases flow by 2 full levels.

So if your baby is using a Level 2 nipple, for example, and you're feeding with thickened formula, expect it to feel more like a Level 1 or slower. A level 3 nipple may flow more like a level 2 nipple when used with thickeners.

how to get the best performance from your mōmi nipple

Because our patented mōmi nipple features a longer internal duct to support natural oral mechanics, it's especially important to avoid clogs when using thicker liquids to feed. Here's how to keep things flowing smoothly:

best mixing practices:

• • Liquid-based thickeners (like SimplyThick or Enfamil AR liquid) work best and are least likely to clog.
  • Powdered formula or powdered thickeners can also work—but only if fully dissolved.

pro tips for mixing powdered thickeners:

1. Use warm liquid—just above body temperature—for best solubility.
2. Sprinkle powder slowly onto the surface of the liquid to avoid clumping.
3. Gently stir or swirl under the surface—don’t shake or beat the mixture, which can cause clumps.
4. Let the bottle rest for 10 minutes after mixing to allow any small particles to fully disperse.

If you do encounter a clog, simply remove the nipple and rinse or clear the duct with the included mōmi cleaning tool.

supporting your feeding goals

No two babies feed exactly alike, and needing thickeners in baby’s formula or breast milk doesn’t mean giving up on your feeding goals. At mōmi, our goal is to give parents tools that adapt to their baby's needs, whether that includes a variety of nipple flow rates and bottle sizes,  or science-backed tips for feeding success.

If you have any questions about using thickeners with your mōmi bottles, don’t hesitate to reach out. We’re here to help you and your baby thrive—one feed at a time.