Key Differences Table Between Similac Isomil and Gerber Soy
| Features/Aspect | Similac Soy (Isomil) | Gerber Good Start Gentle Soy |
|---|---|---|
| Ideal For | Babies with lactose sensitivity or vegetarian diet | Babies with lactose sensitivity or vegetarian diet |
| Type | Soy-based formula | Soy-based formula with hydrolyzed protein |
| Primary Protein Source | Soy protein isolate | Hydrolyzed soy protein isolate |
| Carbohydrate Source | Corn syrup solids and sugar | Corn maltodextrin |
| Fats and Oils | Soy, coconut, high-oleic safflower oils | Palm olein, soy, coconut, high-oleic safflower oils |
| Nutritional Support | Fortified with DHA, lutein, vitamin E, minerals | Essential fatty acids, calcium, vitamin D |
| Ease of Digestion | Designed for easy digestion, suitable from birth to 12 months | Gentle on the stomach, suitable from 6 to 12 months |
| Non-GMO | Yes | Yes |
| Prebiotics | Short-Chain Fructooligosaccharides (scFOS) | None |
| Specific Benefits | Lactose-free, vegetarian-friendly, nutrient-rich | Gentle, hydrolyzed protein for easier digestion, non-GMO |
This article aims to compare two popular Soy formulas in the US: Similac Soy (Isomil) and Gerber Good Start Gentle Soy.
We will analyze their ingredients and nutritional information to give you the information you need to make the best decision for your baby.
Let’s get after it!
***Important: Soy formulas are not recommended for infants younger than six months of age due to estrogen content and should not be used to treat CMPA until a pediatrician gives the okay.
Related Read: Similac Soy vs Similac Sensitive
Our Short Answer
If we had to choose one, we would go for Gerber Soy for the following reasons:
- It has hydrolyzed protein, which means it’s easier to process by babies
- It has corn maltodextrin instead of corn syrup solids and sugar
Even though Similac is ahead in terms of the fat blend and prebiotics, Gerber’s pros outweigh Similac’s.
Remember that the introduction of a soy-based formula should be done after consulting with your pediatrician, to ensure it’s the right fit for your baby’s nutritional needs.
With over 100,000 orders delivered globally since 2019, Organic's Best offers clean, safe, and nutritionally rich formulas and snacks.
Free shipping over $100, commitment to freshness and authenticity.
- Express delivery in 2 to 5 business days
- Sourcing from European manufacturers
- Minimum shelf life of 6 months
- Climate-Controlled Warehouse
Give your little one the best start.
CODE 'BLW' for a 5% discount in all orders
Overview of the Two Formulas
Similac Soy Isomil and Gerber Good Start Soy are both designed for infants with lactose sensitivity or who need a milk-free diet.
They offer complete nutrition with soy protein isolate, are fortified with essential nutrients like DHA, and are gentle on digestion.
Both are suitable from 6 to 12 months.
Similac Soy
Similac Soy, also known as Similac Soy Isomil, is designed for fussiness and gas relief for infants sensitive to lactose. These are its key features:
- Composition: It is a complete nutrition formula with soy protein isolate as its primary source of protein, suitable from birth to 12 months.
- Nutrient Profile: Similac Soy is fortified with DHA for brain development, lutein for eye health, and vitamin E for growth. It is also enriched with minerals, such as calcium and iron, which are crucial for your baby’s development.
- Suitability: It can be a suitable option for babies with galactosemia, congenital lactase deficiency, or families seeking a vegetarian-based formula.
- Ease of Digestion: The soy protein in Similac Soy is designed to be easy on infants’ digestive systems, which can reduce discomfort from gas and fussiness.
Gerber Soy
Gerber’s Soy Formula, known as Gerber Good Start Soy, caters to infants needing an alternative to milk-based formulas. These are the features they sell:
- Composition: It provides a soy-based, milk-free formula that’s also lactose-free for babies with sensitivities.
- Nutritional Support: It includes essential fatty acids, similar to those found in breast milk, which promote brain and eye development. The formula is rich in calcium and vitamin D for bone health.
- Tailored for Digestion: Gerber Soy is gentle on the baby’s stomach and aims to provide comforting nutrition, especially for little ones who might experience minor digestive issues with cow’s milk-based formulas.
- Non-GMO: The formula is also non-GMO, reassuring parents who prefer to avoid genetically modified ingredients in their baby’s diet.
Nutritional Composition
Similac Soy and Gerber Soy both use soy protein isolate, suitable for lactose intolerance, with Gerber’s protein also hydrolyzed for easier digestion.
Gerber has a better carbohydrate source with maltodextrin, having fewer simple sugars than Similac’s corn syrup solids.
In fats, Similac Isomil is preferable as it doesn’t contain palm olein, linked to poor calcium absorption.
Protein Content
Protein is critical for the building blocks of life, essential in forming muscles, organs, and the immune system. In baby formula, the protein content must be sufficient to support rapid growth and development in the first year of life.
- Similac Soy and Gerber Soy: Both formulas use soy protein isolate as their primary source. This is because soy protein is plant-based and lactose-free, making it a suitable alternative for babies intolerant to cow’s milk protein or lactose. However, Gerber goes a bit further and the soy protein isolate is also hydrolyzed.
Gerber wins in protein content thanks to having enzyme-hydrolyzed soybean protein isolate. This means that apart from being isolated (lactose-free), it’s broken down, making it easier to digest.
Important: Soy formulas have higher protein content because plant-protein has less bioavailability, which means that it’s not as efficient as animal protein, and the organism does not process it the same way.
*Learn more: Soy in Formula
Carbohydrate Content
Carbohydrates are the primary energy source for babies and support the central nervous system’s development, including the brain. Quality baby formulas offer easily digestible and healthy carbohydrates for little systems.
- Similac Soy: The carbohydrate source in Isomil is corn syrup solids.
- Gerber Soy: The carbohydrate source in Gerber is corn maltodextrin.
Gerber wins the carb battle. This is because maltodextrin has fewer simple sugars and a more neutral flavor, which is better for babies in the long run. Corn syrup solids are the most common alternative to lactose in US-based formulas, but they are not ideal. In addition, Similac Isomil adds table sugar on top of the syrup solids.
*Learn more: Maltodextrin in Formula | Corn Syrup in Formula
Fats and Oils
Fats are crucial in baby formulas, as they provide essential fatty acids necessary for development, including brain development, and help absorb certain vitamins.
- Similac Soy has soy, coconut, and high-oleic safflower oils.
- Gerber Soy includes palm olein, soy, coconut, and high-oleic safflower oils.
On paper, Similac Isomil wins the fat battle because it does not add palm olein, an ingredient linked to poor calcium absorption.
*Learn more: Palm Oil in Formula
Prebiotics and Probiotics
Probiotics are the ‘good’ bacteria that live in our intestines, and prebiotics are non-digestible fibers that provide food for these beneficial bacteria. Together, they support a healthy digestive system, which can play a role in overall health and well-being. *Read: Prebiotics and Probiotics in formula
- Similac Soy: This formula contains short-chain fructooligosaccharides (scFOS), a prebiotic that nourishes beneficial gut bacteria. However, it does not have probiotics, the live cultures themselves.
- Gerber Soy: Gerber does not add any prebiotics or probiotics because it does not need them thanks to having hydrolyzed protein. The formula is already very easy to digest.
Best Places to Buy Similac Soy and Gerber Gentle Soy
Similac Isomil
Gerber Gentle Soy
What are the Best Alternatives to Similac Isomil and Gerber Gentle Soy?
Sometimes, after trying a formula, you find out your baby dislikes or manages it appropriately. Here, you have the alternatives to these two formulas, in case you need them.
- Enfamil ProSobee (Soy): As one of the most common alternatives, Enfamil ProSobee is a soy-based formula designed for sensitive bellies, aiming to reduce fussiness and gas. It is fortified with the necessary vitamins and minerals for infant development. *Read: Enfamil Soy vs Similac Soy
- Nutramigen: This hypoallergenic formula is designed for infants with cow’s milk protein allergies. It contains extensively hydrolyzed proteins, broken down into small pieces to reduce the risk of an allergic reaction. *Read: Similac Soy vs Nutramigen
- Alimentum: Similar to Nutramigen, Alimentum is a hypoallergenic formula. It’s designed for babies with a sensitivity or allergy to cow’s milk protein, offering a different brand option with similar benefits. *Read: Similac Soy vs Alimentum
- Our Favorite – Hipp HA: Hipp HA is prized for its blend of prebiotics and probiotics alongside its organic ingredients. It’s intended for babies with sensitivities but should be avoided by those with diagnosed cow’s milk protein allergy (CMPA). Hipp HA is often favored for its commitment to high-quality, organic ingredients, including prebiotics and probiotics. *Read: Hipp HA vs Alimentum | Hipp HA vs Nutramigen
Last Words
We hope this article helps you find the best formula for your baby.
Remember that Soy formulas should not be the first option and you should always check with a pediatrician before offering one.
If you have further questions, leave a comment or contact us through our homepage.
Happy feeding!
We’re Maria and Alberto, a married couple and educators who are nutrition enthusiasts. Even before we had kids, we were already crazy about nutrition.
We’d read scientific articles, watch videos from nutritionists, and spend hours listening to nutrition podcasts.
Today, we continue doing this, but in a different way, as we’ve learned to sift through the noise and trends. Nutrition, like any other field of knowledge, the more you read and learn, the more you develop a comprehensive understanding of reality, and that’s what has happened to us.
Before having our first child, we focused on learning everything we could about child nutrition, using the same techniques we had already employed, backed by our extensive knowledge in nutrition.
Our mission is to help other parents with their children’s nutrition, to help them become the best versions of themselves.
If we are what we eat and drink, which is absolutely true, let’s do it right!
