6 Best Soy Formula for Constipation 2022

Is your baby having constipation because of their formula? We empathize with you because we have been there, and it’s no fun!

We ended up doing trial and error experimenting with different formulas until we finally switched to soy formula, and that is when the miracle happened. Like us, many parents have also seen improvements with gas, colic, and constipation when they introduced their babies to a soy formula.

In this article, we will be discussing the benefits and possible side effects of soy and how it can help with constipation. We will also be recommending some great soy formula brands that you can choose from. Just keep in mind that babies react to all formulas differently and that you might need to try a few to get the one that best works for your baby. Also, we recommend checking with your pediatrician before introducing your baby to soy formula in case constipation does not seem to improve.

Is soy formula good for constipation?

According to several studies, constipation in young children has been linked to intolerance to cow milk-based products, including formula. It is common for small babies with an immature digestive system not to be able to digest milk components, particularly proteins and lactose. This can cause many tummy problems, including constipation. 

For these children, switching to soy formula is recommended as an alternative, and experts say it can help clear up constipation. This is because soy formulas use different sources of carbohydrates instead of lactose and soy proteins. As a result, they are gentler and more tolerable by little tummies.

Reviews of the Best Soy Formula for Constipation

1. Gerber Good Start Soy Powder Infant Formula

This is one of the best soy-based formulas in the market. Unlike other soy-based formulas, Gerber Good Start Soy formula uses hydrolyzed soy proteins that are easy for little tummies to digest. Also, because it has no lactose, many parents have reported improvement with gas, fussiness, spit ups, rashes, and constipation when they switched their babies to this formula. 

Besides being gentle, this infant formula provides the wholesome nutrition of Gerber Good Start line to help with robust growth and development. It is fortified with essential minerals and vitamins such as Calcium and Vitamin D to build strong teeth and bones, and there is also DHA to support eye and brain development.


  • Non-GMO
  • The only formula with hydrolyzed soy proteins that are easy to digest
  • Does not contain unhealthy ingredients like corn syrup
  • Specially designed container to help prevent contamination and preserve the freshness of formula
  • Pleasant taste and flavor
  • Mixes well


  • Expensive

2. Enfamil Prosobee Soy Sensitive

ProSobee is a soy-based formula from one of the top baby formula brands. According to Enfamil, it is a great option if you think your little one’s tummy issues are contributed by taking a milk-based formula.

The formula is designed to be gentle on sensitive tummies and may help reduce fussiness, gas, colic, and constipation. Like other Enfamil baby formulas, it contains high amounts of DHA to help nourish and develop your baby’s brain, which is a plus.


  • Nutrients dense
  • Contains higher levels of brain nourishing DHA
  • Gentle on the stomach
  • Easy to mix


  • Some babies dislike the taste
  • May react differently to some babies
  • Expensive

3. Similac Soy Isomil

Soy Isomil by Similac is a great alternative for babies that have digestion problems like gas and constipation from taking milk-based formula with lactose. It uses soy proteins that are easier for your baby to digest and may help eliminate uncomfortable tummy problems, including constipation. 

The formula also contains Similac’s OptiGrow, a special blend of DHA, Lutein, and Vitamin E. This is a powerful combination of ingredients for the baby’s brain, eye, and immune system development.

One of the things we noted is that this formula contains less corn syrup than other soy-based formulas. Corn syrup is approved by the FDA as a safe source of energy and sweetener, but it is controversial within parents’ circles. That is why we were concerned to learn that the formula also adds in a bit of sugar.


  • Non-GMO
  • Contains essential nutrients for brain and eye development
  • Pleasant flavor
  • Less percentage of corn syrup


Contains high amounts of sweeteners that are unhealthy

4. Earth’s Best Non-GMO Plant Based Infant Formula

Earth’s Best Non-GMO plant Based Infant Formula is the only organic soy formula option we have in the market. It uses high-quality organic and non-GMO sourced ingredients and uses no artificial flavors, colors, or preservatives, making it a healthy choice for your baby. As a plant-based formula, it may be easier for your baby to digest than milk-based formulas and help to eliminate constipation.

Earth’s Best prides itself in providing the best nutrients for your baby. For example, it is the only formula that uses whole soy protein while others use soy isolate, which is usually soy that has been stripped of some nutrients. It also provides DHA, lutein, and ARA for brain development, prebiotics for immune support, and a long list of vitamins and minerals that keep your baby healthy.


  • Organic certified
  • Contains prebiotics for immune development


  • Pricey
  • Some babies dislike the taste, but this is common with soy formulas
  • Some babies experienced tummy problems, including hard poop

5. Mama Bear Soy-Based Powder Infant Formula

The Mama Bear offers soy-based infant formula without an expensive price tag. According to Amazon, its nutritional content is comparable to Similac Isomil and Enfamil Prosobee, and we love that it doesn’t have excess sugar like the two. As a soy-based formula, it can help babies who have constipation, gas, and fussiness from lactose intolerance. 

If you are on a budget, this formula has all the essential ingredients you would find in its expensive counterparts, including DHA, ARA, and lutein for eye, brain, and immune development. It also adds prebiotic FOS that provides a source of food for probiotics so your baby’s digestive system can stay top shape.

One thing you may need to worry about is that it’s not non-GMO or organic, so the quality of its ingredients is questionable.


  • Easy to mix
  • Tasty
  • Budget-friendly


  • May contain GMOs

6. Baby’s Only Organic Plant-Based Toddler Formula

This is the only organic soy toddler formula on the list. It is designed to be a supplement for older babies above 12 months who are sensitive to dairy protein and lactose. If your child is unable to digest milk protein and lactose they can have constipation, among other digestive problems. Baby’s Only Organic soy formula can help them get relief from these digestive problems. Furthermore, many parents are quite pleased with how the formula smells and say their kids enjoy taking it.

The formula is made using pure and high-quality organic ingredients that are safe and healthy. The company goes out of its way to ensure that the formula does not use GMOs or controversial ingredients such as corn syrup, palm oil, or hexane processed DHA. Instead, the formula provides high-quality soy protein, carbohydrates from brown rice syrup, vitamins, and minerals needed for growth and development.


  • Uses pure and high-quality organic ingredients
  • Gluten-free
  • Does not contain controversial ingredients such as corn syrup, palm oil, or hexane extracted DHA
  • Pleasant vanilla flavor and taste


  • Some babies have spit ups
  • Doesn’t have an option for infants below a year

Soy-Based Formula for Constipation Guide

How to relieve constipation from Soy formula

If your baby is suffering from constipation even after switching to soy formula, there are a few things you can do to help.

  • Consider a formula with probiotics. Probiotics are good bacteria that help maintain a healthy gut to eliminate constipation and other digestive issues.
  • Give your baby more fluids as dehydration also causes constipation. If it’s an infant you can give about 2 to 4 ounces of water or diluted prune juice one to two times daily. For bigger toddlers, a minimum of 2 to 3 glasses per day is recommended.
  • Give your baby more fiber-rich foods. If your baby is already 4 months old and is taking solid foods, you can try adding high fiber foods like cereal, soft fruits, and vegetables.
  • Use glycerin suppository or high mineral oil. If your baby has really bad constipation and is having serious pain when trying to pass stools, they will need stool softeners like glycerin or mineral oil to clear up the backed-up stool. But, you need to consult with your pediatrician to guide you on how to apply the treatment.

Benefits of soy formula

Soy formulas are made from soy proteins combined with plant-based carbs, fats, and essential vitamins and minerals necessary for infants’ growth and development. Therefore, they serve as a substitute for breast milk and cow milk-based formula and an ideal choice for families observing vegan or kosher diets.

Second, soy formula is better tolerated in babies who are unable to digest lactose, the main source of carbohydrate in milk-based formulas.

Some parents also believe soy formula helps relieve colic, gas, and fussiness. However, there is no scientific evidence, and experts warn against switching to soy formula from breast milk or milk-based formula unless you are advised to do so by your medical practitioner.

Soy formula issues/problems 

Soy formulas are approved for use by the FDA and do provide complete nutrition for infants and babies, but they also have some concerns.

Soy formula comes with several issues, the first one being that some babies are allergic to soy. And according to, about 20 percent of babies with cow milk allergies also tend to be allergic to soy. So giving these babies a soy formula could actually cause or worsen digestive problems such as gas, fussiness, and constipation. But the good thing is kids outgrow both of these allergies in their infancy and toddlerhood.

The second problem with soy-based formulas is that they can make stool harder, causing or worsening constipation in some babies. But soy has also been shown to reduce constipation in babies with cow milk intolerance. 

The third issue is that soy contains phytoestrogens, which trigger estrogen-like activities in the body. Some experts have raised concerns that phytoestrogens can affect immune, thyroid, and sexual development. Research is still ongoing on the health impact of phytoestrogens on infants and adults.

How to relieve constipation from soy formula

Soy formula can cause stools to be firmer and even cause constipation in some babies. If your baby is experiencing this, you can try giving them small amounts of water or diluted prune juice to increase hydration so stools can be softer according to the American Academy of Pediatrics. If the child is older, high-fiber foods like whole-grain cereals, veggies, and fruit can also help with constipation.

Remember, constipation is usually from mild dehydration, so dietary changes and watchful waiting are always the doctor’s advice. Furthermore, parents are also urged not to use interventions like enemas or suppositories unless advised to do so by their pediatrician.

Will soy formula help with constipation?

Yes, Pediatrics sometimes recommends a switch to soy formula to find relief from constipation.

Switching to a soy formula can help clear constipation because it contains different ingredients from milk-based products. Young children get constipation from not being able to digest lactose, which is a sweetener and a source of carbohydrate in the milk-based formula.

History of soy formula

The history of soy formula dates back to the 1920s when scientists began experimenting on non-milk-based formulas. The soy formula was the first to be developed by Hill, and according to studies, it became available in the United States in 1929. Originally, it was invented for babies who were allergic to cow milk, and not necessarily cow’s milk-based formula. But there were several problems. One was that the soy formula lacked many essential vitamins, fearing that adding vitamins for fortifying would also add in allergens. The result was reports of deficiencies diseases like goiter. Also, there were complaints of loose stools caused by the high amount of soy flour.

Over the years, these issues were resolved by fortifying the soy formula and using soy protein isolate, which removed excess fiber and better stools similar to those of infant-fed milk-based formulas. Today soy-based formulas account for about 12% of formula sales in the United States.