Similac® Soy Isomil®

Complete nutrition for sensitive tummies

Fussiness and gas can be a common part of feeding your baby.

Similac Soy Isomil is specially designed to comfort with the gentleness of soy to soothe the tummy.

Soy-based formulas have been clinically shown to help reduce feeding problems. No other soy-based formula has been studied more than Isomil.

Has OptiGRO to support your baby's brain and eye development.

If your baby’s fussiness or gas seems excessive, ask your physician about switching to Similac Soy Isomil.

Soy formulas are not recommended for premature infants with birth weights of less than 1800 g.

Similac Soy Isomil formula product for infants

Available In:

Similac Soy Isomil 1.45lb formula for infants 1.45-lb Powder

Similac Soy Isomil 12.4oz formula for infants 12.4-oz Powder

Similac Soy Isomil 32oz formula for infants 1-qt Ready to Feed

Nutrition Information

Powder / 1.45 lb

Serving size: 100 Cal (prepared as directed)*

Amount per serving

  • Calories:


  • Volume, mL:


  • Protein, g:


  • Fat, g:


  • Carbohydrate, g:


  • Water, g:


  • Linoleic Acid, mg:


Vitamins & Minerals

* Nutrient values are applicable when prepared as directed.

Similac® Soy Isomil®
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Rated 5 out of 5 by from Very helpful We started supplimenting with formula for my son at 5 days old. We tried the Pro-Advanced formula, but we soon discovered that with that aND breastmilk, he has awful reacoons to dairy. After cutting dairy and switching him to the Isamil formula and had no other problems so far. We had also used this formula for our other two children when they were infants with great results! It's a really great formula for infants with dairy problems.
Date published: 2017-10-28
Rated 5 out of 5 by from Amazing This formula helped tremendously. She went from constipated, fussy, and gassy to a happy healthy baby within 10 hours
Date published: 2017-10-18
Rated 5 out of 5 by from Very helpful for my son's twin boys I had always given my children soy formula after breastfeeding for a couple of months due to the amount of allergies in our families. It was the best formula for them. When my son & his wife recently had twins she decided to breastfeed and give formula to supplement. They tried one brand and then switched to Similac Pro Sensitive, but there were some issues. The twins were continuously spitting up and sometimes it would be chunky. From the beginning I had suggested they try the soy formula.They just turned 3 months and they finally decided to go with my suggestion. What a huge difference it has made with the babies. Less fussiness and way less spitting up. I think they wish they had taken my advice from the beginning.
Date published: 2017-10-08
Rated 5 out of 5 by from Only Formula we could use This is by far the best formula out there!
Date published: 2017-10-02
Rated 5 out of 5 by from Breast feeding life saver! My sweet little angel is 16 days old today. After a whole week of exclusively breast feeding and no sleep we figured out she has a dairy sensitivity. I've had to cut out all dairy from my diet to be able to continue feeding her partially. Similac soy has made it possible for me to feed her while my body is cleansing from all the dairy and is gentle enough for her to finally be able to sleep. We could not be happier with the results and the product.
Date published: 2017-09-30
Rated 4 out of 5 by from This product helped my baby We started off with regular similar formula but quickly learned our little princess has a lactose intolerance and switched to soy. It took over a week to finally get adjusted with her stool back to normal, less fussiness and trapped gas. But I’m so glad we figured the problem out so quickly and was able to fix it.
Date published: 2017-09-29
Rated 5 out of 5 by from Gentle on Baby's Stomach We tried all the samples our doctor gave us including the other brands, but found our baby has some milk sensitivity and switched to soy. She spits up less than before, and her fussiness is in check! My friend recommended it and I'm glad she did!
Date published: 2017-09-27
Rated 3 out of 5 by from This product is very good, but.... This product seems to be working as far as the frequent spiting up. However, every time I give my grandson a bottle, he has runny stool. What should I do?
Date published: 2017-09-22
Rated 5 out of 5 by from It is AMAZING. After, trying several different ones. This one is the ONLY one that been great. No spit up and NO diarrhea. GREAT PRODUCT! After trying several different Similac's and several different Geber and Enfamil. Similac Soy is amazing. She immediately started to feel better. She doesn't spit up at all and she doesn't have diarrhea at all like she was with all the rest. Similac has always been my brand but, I didnt know what to do when she couldn't keep down the Advance or the Sensitive.
Date published: 2017-09-18
Rated 5 out of 5 by from Love it Helped my twins with their reflux problems!
Date published: 2017-09-17
Rated 5 out of 5 by from Love this! We love the similac soy formula for our baby's sensitive belly!
Date published: 2017-09-09
Rated 5 out of 5 by from We love Similac! We started our new baby girl on Similac Advance but she was fussy and crying all the time, so we switched to Similac Soy Isomil and it was a godsend. She has been a completely different baby since we switched. She is such a happy baby & I am so thankful for Similac.
Date published: 2017-09-06
Rated 5 out of 5 by from I love it. When i had my son i strictly wanted to breast feed but after a while i started noticing that he would puke everything up with in minutes of being done eating or he would be so constipated he would scream in pain. No matter what i did to my diet nothing worked. Well our doctor found out he was lactose intolerant and allergic to my breast milk so the recommended that we try soy. Ever since i started him on soy formula he has been able to eat more and go better. Just wish i could by bulk in the similac formula he goes through a can of the powder ever 3 days and goes through the premade bottles every day . He eats so much of it.
Date published: 2017-08-28
Rated 5 out of 5 by from Similac soy saved our sleepness nights lol My grand baby had been through 4 formulas before we started similac soy the others did nothing just got worse symptoms now he is happy smiling cooing no more tummy aches no gas happy baby happy home...
Date published: 2017-08-25
Rated 5 out of 5 by from Love it Love this milk for my daughter I wish i could find the ready to use in the stores. They never have them where I stay.
Date published: 2017-08-25
Rated 5 out of 5 by from This product helped so much My daughter was developing a rash using regular formula and was always fussy also had a hard time pooping. We switch because the doctors recommended it and now we couldn't be happier.
Date published: 2017-08-24
Rated 5 out of 5 by from I love this product My daughter dont spit up as much as she was on simliac advance
Date published: 2017-08-17
Rated 5 out of 5 by from Love this Formula Both my boys have had a rough time with Formuals and when we switched to Similac Soy they were completely different babies and we couldn't be more happier ❤️
Date published: 2017-08-17
Rated 5 out of 5 by from Great product Definately recommend this formula
Date published: 2017-08-03
Rated 5 out of 5 by from Like day and night... Proud new Mom supplement feeding a beautiful baby girl, while in the hospital she was drinking Pro Sensitive Similac formula, we continued the regimen of every other feeding; changing between that and breastfeeding. Long story short my husband and I noticed she was fussy and constipated and had a terrible times with BM's when she was able to. We grew very concerned about the effects this had on her so we asked the doctor what we could do to help alleviate the situation. She recommended to switch to a soy based milk and gave us a few sample cans and within a day noticed a night and day difference with our babygirl. She was no longer fussy and has not been as gassy. Thank you.
Date published: 2017-07-29
Rated 5 out of 5 by from Happy Baby, Happy Life Changing my son's formula from Advance to Soy was like Night and Day with him. Lactose Allergies are quite common in his genetics. Love SIMILAC SOY
Date published: 2017-07-25
Rated 5 out of 5 by from It's AMAZING My son started out on Similac in the blue can which made him very constipated. So we switch him to Similac Soy and it is AMAZING! No more constipation.
Date published: 2017-07-22
Rated 5 out of 5 by from Best Option For Our Baby After 36 hours of our baby crying after taking each sip and then spitting up everything in his bottle at the hospital as a newborn, soy was a last resort for us (while in he hospital). With the first sip, we knew that this formula was going to be the one. Thank you Similac for creating such a great product and for making our baby boy happy!
Date published: 2017-07-21
Rated 3 out of 5 by from Gave my baby terrible gas and constipation My son is 3 weeks old and has colic due to milk allergies. I tried this formula to help relieve his tummy problems with feeding. It made him worst. The formula gave him terrible gas and made him constipated. Now I'm lost on what formula to try next.
Date published: 2017-06-29
Rated 2 out of 5 by from Did not work for my little one I've been breastfeeding my son since he was born. He's almost 5 months now and I'm slowly switching him to formula and I'm having a hard time looking for formula that works for him. The regular formula gave him hives and bloody stool. My pediatrician recommended soy and so I tried Similac Soy Isomil for about two weeks now. I give him 1 Similac Soy Milk (about 3.5 oz) per day just to start. Every time I give him Similac Soy Isomil, he will either have a projectile vomit or a major spit up after each feeding. He also gets super constipated. I switched him back to breastmilk full time and he tolerated breastmilk with no issues and pooped without straining. So I know it was the soy milk that was causing it. I don't have enough breastmilk for him and so I'm trying to figure out what other alternatives I have.
Date published: 2017-06-27
Rated 4 out of 5 by from Good but not great I have a 4 month old daughter and we have tried just about every Similac formula there is. We started with the supplementation formula while I was still breastfeeding, then switched to Similac Sensitive when I stopped breastfeeding due to excessive spit up and her being gassy all of the time. About the same time, her pediatrician prescribed Xantax for reflux. She was still very gassy and going through multiple changes of clothes each day from so much spit up, so we tried the Similac Total Comfort. No change. We then tried the Similac Soy Isomil. Drastic improvement for spit up, but now she is waking at around 2 am every morning grunting and crying as if her belly hurts and won't go back to sleep. On all of the other forumals we tried, she has slept through the night. So, we tried Similac Alimentum hoping that would do the trick - it would help with the spit up like the Soy formula did but also help her to start sleeping through the night again. No such luck, she refused to eat the Alimentum. About the only formula we haven't tried yet is the Similac Spit Up, but we aren't sure if it's even worth trying. It seems as though our choices are excessive gas and spit up or hardly any spit up at all but waking at 2 am every morning. Since you can't purchase sample sizes, we have been left with a huge hole in our wallet and a pantry full of partially used formulas! Offering sample sizes for purchase would be great for families like us who just can't seem to find the right formula for our daughter.
Date published: 2017-06-25
Rated 5 out of 5 by from this product is a lifesaver This Similac soy saved my baby's butt. My poor baby from the time he was born for the first three or four weeks of his life had a raw butt and we could not figure out what was causing it until his doctor switched him to Similac soy and as soon as we switchef him it went away
Date published: 2017-06-23
Rated 5 out of 5 by from This formula is a life saver!!! Oh wow, I don't even know where to begin. Our little boy was severe colic starting at 2 weeks old. Crying all day every day for 4 months straight, it was HORRIBLE.He was also having blood in his stool because he had a milk protein allergy that we didnt discover until he was about 4 months old. We tried 6 different formulas and Similac Soy was our seventh formula. And FINALLY the blood in his stool stopped and after a few days of being on it, he was SO much happier and actually sleeping. A completely different baby!!! I can't thank Similac enough for making this saved our sanity, which sounds dramatic, but if you've ever had a colicky baby you know what I'm talking about. If you're baby has a milk protein allergy, try this formula!! I know most babies allergic to milk are also allergic to soy, but not ours. In fact, he couldn't even tolerate all of the hypoallergenic formulas. This formula is a LIFE SAVER!!! We are happy and our baby is happy!!
Date published: 2017-06-17
Rated 5 out of 5 by from Love this formula My son is 4 weeks old and he was eating Gerber Goodstart Gentle and he was spitting up all of it half an hour after feedings. We switched to Similac Isomil and he didn't have any trouble! He loves it and he isn't fussy especially during the nighttime feedings. It's easy on his tummy as well.
Date published: 2017-06-15
Rated 5 out of 5 by from Finally a formula that worked for my daughter I try similac advance, total comfort, sensative. I got frustrated because nothing seem to in till ER recomended similac soy and thanks god it work. I will like some samples or coupons since im a single mother. Thank you similac soy.
Date published: 2017-06-06
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