Key Differences Table Between Similac Soy and Alimentum
| Features/Aspect | Similac Soy (Isomil) | Similac Alimentum |
|---|---|---|
| Ideal For | Babies with lactose intolerance | Babies with severe cow’s milk protein sensitivities or allergies |
| Type | Soy-based formula | Hypoallergenic formula |
| Primary Protein Source | Soy protein isolate | Extensively hydrolyzed cow’s milk protein |
| Carbohydrate Source | Corn syrup solids | Corn syrup solids |
| Fats and Oils | High oleic safflower, soy, coconut oils | High oleic safflower oil, MCTs, soy oil |
| Nutritionally Complete | Yes, includes essential vitamins and minerals | Yes, includes essential vitamins and minerals |
| Ease of Digestion | Designed for easy digestion | Designed for easy digestion with fast relief for food allergies |
| Prebiotics | Short-Chain Fructooligosaccharides (scFOS) | 2’-FL HMO (Human Milk Oligosaccharide) |
| Specific Benefits | Lactose-free, suitable for plant-based diets | Alleviates colic symptoms due to protein sensitivity, hypoallergenic |
This article will compare two popular Similac formulas for babies with allergies and sensitivities: Similac Soy vs Similac Alimentum.
We will analyze their nutritional composition and ingredients to help you choose the best formula 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 OK.
Related read: Similac Soy vs Enfamil Gentlease
Our Short Answer
If you are hesitating between Similac Isomil (Soy) and Alimentum, it means that your baby has difficulty digesting cow’s milk protein, or is allergic.
If that is your case, we recommend Alimentum over Isomil.
This is due to the following factors:
- Cow’s milk protein has a higher bioavailability than soy protein. This means that it is more easily absorbed and utilized by the body.
- It has MCTs, fats that are easily absorbed by the body.
- It has a prebiotic that is highly beneficial for babies, and found in breast milk: 2′-FL HMO.
That said, if your baby’s difficulty is related to lactose and not cow’s milk protein, I would explore other alternatives such as the ones below in this article.
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 is a lactose-free, soy-based formula for babies with lactose intolerance, offering complete nutrition with plant-based proteins and ease of digestion.
Similac Alimentum is hypoallergenic, designed for babies with severe cow’s milk protein sensitivities or allergies, providing fast relief and a nutrient-rich profile.
Similac Soy
Similac Soy, also known as Similac Soy Isomil, is a soy-based formula designed for babies who have difficulties digesting lactose, the sugar found in cow’s milk. It is a lactose-free option that provides a complete nutritional profile to ensure your baby receives essential nutrients during their first year of life. Here are some of the noteworthy attributes of Similac Soy:
- Lactose-Free: An ideal choice for infants who are lactose intolerant or who experience fussiness and gas due to lactose sensitivity.
- Nutritionally Complete: Contains a blend of vitamins, minerals, and nutrients, such as DHA for brain development and Vitamin E for cellular health, which mimic the profile in human milk.
- Plant-Based Proteins: Utilizes high-quality protein from soy to provide a cow’s milk alternative for infants with dietary restrictions, allergies, or family preferences for plant-based nutrition.
- Ease of Digestion: The soy protein isolate in Similac Soy Isomil is designed to be easy for little tummies to digest.
Alimentum
Similac Alimentum is a hypoallergenic formula crafted for babies with a sensitivity or allergy to cow’s milk protein. It provides a specialized solution for parents dealing with these challenging feeding issues. Here’s what sets Alimentum apart:
- Hypoallergenic: Contains a predigested milk protein that reduces the potential for allergic reactions in sensitive babies.
- Fast Relief: Designed to alleviate common food allergy symptoms like colic due to protein sensitivity, often within 24 hours.
- Nutrient-Rich: Like all Similac products, Alimentum offers a complete range of nutrients, including DHA and ARA for eye and brain development.
- For Severe Sensitivities: It’s especially beneficial for babies with severe dairy allergies, multiple food protein intolerances, or other gastrointestinal conditions.
Nutritional Composition
Similac Soy uses soy protein isolate, suitable for lactose intolerance and those avoiding animal proteins. Alimentum features extensively hydrolyzed cow’s milk protein, ideal for babies with allergies, offering better bioavailability.
Both use corn syrup solids for carbohydrates, with Alimentum’s fats including easily digestible MCTs, offering a slight advantage.
Protein Content
Protein is essential for the growth and development of infants, serving as the building blocks for muscles, organs, and the immune system.
- Similac Soy: The protein content in Similac Soy comes from soy protein isolate, a high-quality plant-based protein. It’s an alternative for those avoiding animal-derived proteins, and it’s also the choice for infants with lactose intolerance. Soy protein isolate is processed to remove most of the fats and carbohydrates, leaving primarily a clean protein that’s suitable for babies.
- Alimentum: Alimentum features a hydrolyzed protein formula, which means that the cow’s milk protein has been broken down into smaller units, making it easier to digest and reducing the chance of allergic reactions. This process also helps provide quicker relief from symptoms associated with protein sensitivities, such as colic.
Both formulas will work if your baby can’t or has problems digesting cow’s milk protein. Similac Isomil uses soy protein, which makes the formula suitable for lactose sensitivities as well.
Alimentum uses extensively hydrolyzed protein, meaning it’s predigested and safe for allergic babies to consume. Hydrolyzing protein is difficult; that’s why Alimentum comes at a higher cost.
The protein from Alimentum (cow’s milk protein) has better bioavailability than soy protein, which means it’s used more efficiently by your baby’s organism.
*Learn more: Hydrolyzed formulas | Best hypoallergenic formulas
Carbohydrate Content
Carbohydrates are a critical energy source for infants, and it’s essential to select a formula that provides this macronutrient in an easily digestible form.
- Similac Soy: Instead of lactose, Similac Soy contains corn syrup solids as its primary carbohydrate source. Corn syrup solids are a modified form of cornstarch used in many lactose-free products to provide the necessary carbs for a baby’s energy needs.
- Alimentum: Alimentum’s carb source is also corn syrup, which acts as an alternative carbohydrate to lactose, reducing the risk of gastrointestinal discomfort in sensitive infants. The small size of the carbohydrate particles after hydrolysis also aids in digestibility and suits the metabolic requirements of infants who need hypoallergenic nutrition.
Both formulas have the exact same type of carbohydrates: Corn Syrup Solids. This ingredient is the standard alternative to lactose in US-based formulas. While it’s not the best option because of its high sugar content, it’s a safe and efficient alternative.
*Learn more: Corn Syrup in Formula
Fats and Oils
Fats are a concentrated energy source and are necessary for brain development, vitamin absorption, and maintaining body temperature.
- Similac Soy: The fat blend in Similac Soy combines high oleic safflower, soy, and coconut oil. This mixture aims to replicate the natural balance of fats in breast milk and support overall growth and development, including brain and eye development, due to essential fatty acids.
- Alimentum: Alimentum’s fat profile includes high oleic safflower oil, medium-chain triglycerides (MCTs), and soy oil. MCTs are more easily absorbed and digested fats, benefiting babies with fat absorption problems or certain gastrointestinal conditions.
On paper, the fat blends of both formulas are similar. However, Alimentum would technically be the winner due to its use of MCTs, which are easier to absorb and digest.
Prebiotics and Probiotics
Including probiotics and prebiotics in infant formulas is a nutritional advancement designed to support the development of a healthy gut microbiome in infants, which is crucial for their digestion and overall well-being. Probiotics are live beneficial bacteria, while prebiotics are food components that promote the growth of these helpful bacteria.
Similac Soy and Alimentum both contain prebiotics, albeit of different types, to aid in digestive health:
- Similac Soy: Similac Soy includes Short-Chain Fructooligosaccharides (scFOS), a prebiotic that helps support the growth of beneficial gut bacteria. Prebiotics like scFOS are similar to those found in breast milk and aid in developing a baby’s immune system by supporting a healthy balance of gut flora.
- Alimentum: Unlike Similac Soy, Alimentum contains 2’-FL HMO (2′-fucosyllactose Human Milk Oligosaccharide), structurally similar to the human milk oligosaccharides found in breast milk. 2’-FL HMO is a potent prebiotic that encourages the growth of good bacteria and supports your baby’s immune system, acting as a preventive against pathogens.
Best Places to Buy Similac Soy and Similac Alimentum
Similac Soy
Similac Alimentum
What are the Best Alternatives to Similac Soy and Alimentum?
If none of the two formulas work for your baby, there are other alternatives that you can look at:
- Nutramigen: Like Alimentum, Nutramigen is a hypoallergenic formula targeting infants with cow’s milk protein allergy. It offers a solution for allergic reaction babies and includes helpful probiotics to support immune health. *Read: Alimentum vs Nutramigen
- Hipp HA (Hypoallergenic): Our top choice for an alternative remains Hipp HA. This organic formula boasts an amazing blend of prebiotics and probiotics, although it is not suitable for babies with diagnosed cow’s milk protein allergy (CMPA). *Read: Hipp HA vs Alimentum
- Hipp Anti-Reflux: This special formula is designed for babies who experience regurgitation or reflux. It contains a natural locust bean gum, which helps the formula to thicken in the stomach, thereby reducing the incidence of reflux.
- Hipp Comfort: Tailored for infants who display symptoms of gastrointestinal discomfort like colic or constipation, Hipp Comfort helps to promote easy digestion. The reduced-lactose formula is enriched with hydrolyzed proteins, which makes it easier for a baby’s digestive system to process.
Important: Hipp Anti-Reflux and Comfort are not intended for babies with milk protein allergies but can be a suitable choice for those with sensitivities to lactose.
Last Words
We hope this comparison has helped you make an informed decision. If you have any other questions, feel free to contact us through our homepage, leave a comment or send us an email.
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!
