Similac Soy Isomil, Ready to Feed Infant Formula with Iron, 32-Fluid Ounce

A soy-based, iron-fortified infant formula with special nutrients found in breast milk, DHA (docosahexaenoic acid) and ARA (arachidonic acid). A nutritionally complete formula for infants with feeding problems such as fussiness, gas, and spit-up; for infants whose parents choose a non-milk-based formula as a first feeding or as a supplement to breastfeeding. A complete formula for infants with allergy or sensitivity to cow’s-milk protein. A feeding for patients with disorders for which lactose should be avoided, including lactase deficiency, lactose intolerance, and galactosemia (Powder preferred).

Quick facts

  • Contains DHA and ARA, two nutrients found in breast milk important for mental and visual development.
  • For common feeding problems such as fussiness, gas and spit-up
  • Soy protein isolate to avoid symptoms of cow’s-milk-protein allergy or sensitivity.
  • Lactose-free to avoid lactose-associated symptoms (eg, diarrhea).

Top reviews

great product, fast shipping, price increase next day….

the product is great and the fast shipping (free 2nd day) is wonderful. I was hoping to make this my routine purchase, but the price was increased next day! From $30.99 to $40.99, a whopping 32% increase! Now I will have to go to stores to get this….
AntoinetteFranklin, GA

Works for us!!

After being on the regular Similac and having the reaction our daughter had with it, we were glad to find that the first alternative worked for us! The soy formula smells a little worse than the original but I’ve definitely had some worse smelling formula than this! I like the subscribe and save option and the packaging started off a little questionable but has gotten so much better over the past two months. Pricing is great, shipping is great and all in all a great product for us.
IngePark Ridge, NJ

Great so far!!!

After exclusively breastfeeding my daughter for 4 months, I had to switch birth control and started losing my milk. I’m doing a fairly good job and keeping up enough that I can nurse her sometimes, so we are supplementing. I started with the Similac Sensitive for spit up, because she has acid reflux that we have not found any medicene to help. My mom recommended to me trying Gerber GoodStart. I noticed it was a complete milk-based formula and the one I had been using was atleast lactose-free. She threw up over and over again and had the diarrhea with it and that was only one feeding. So that was a waste of $15 on my part. I went back to the Similac for spit up, but noticed she was having green stools. After doing my research, I am thinking she has a milk allergy or sensitivity which would be causing so many of her problems in an otherwise completely healthy baby. I bought the Similac Soy Isomil because it is completely cow’s-milk free. I personally think it smells better than any other formula I’ve ever smelled. It doesn’t seem to stain though I haven’t been using it for a long time. I love that it’s ready to feed as it makes it so much easier for me and I think the powder isn’t so great on her stomach. So far she’s doing really well on this formula, and surprisingly hasn’t spit up since she started it, which is a relief as her doctor was planning on sending us to Primary Children’s Hospital to meet with a specialist about her reflux that keeps getting worse. I’m crossing my fingers this works. It’s also nice that at Walmart, where I bought my first bottle, this is the cheapest kind of formula other than the store brand. I love that there are the ready to feed bottles as well, since I hate carrying a bottle warmer everywhere I go because my little girl will not take it cold. On the bottle, it says to discard the formula 1 hour after each feeding has started. Being tight on money, I find this a waste, so when she is done, I simply put it back in the fridge and it is perfectly fine. However, if it’s been sitting there for too long(4-6 hours), I discard it and clean out the bottle before refilling it. She’s been perfectly fine so I’m not worried. I signed up for Similac online so I’m hoping to get some coupons in the mail soon 🙂 Overall, I’m very pleased and would highly recommend.
TisaLake View, IA

on time

I have been getting Similac Soy Isomil from It’s a soy base ready to feed fomula which my 10 month baby boy has been on since 1 month old. He started on milk-base fomula but had lots of gas and tummy problem. We tried another milk-base fomula but it didn’t work neither. The price is good from Amazon. Sometime, when the store has it on sale then the price may be a bit lower than Amazon. So far, we have always get the formula delivery on time.
MervinDurant, FL

Readat made Similac

This product was considerably less on Amazon than in the store to buy, even with shipping costs so my husband and I grabbed a case to have on hand. The product is easy to use and great to have on hand when in need of a quick bottle for our 7 month old son. We also use the ready mades for mixing our rice cereal meals.
ColbyRebuck, PA


about same price, however no tax and comes to your door, which is extremely convenient with 2 small kids
LincolnPhillipsville, CA

Works wonders on babies with lactose intolerance

My son was found to have lactose intolerance when he was 4 weeks old. The doctor switched us to Similac Sensitive Fussiness and Gas (the orange bottle) which helped a little but didn’t help him completely. I then switched to Similac Sensitive Isomil Soy and he was like a whole new baby! The constipation quit and the unstoppable crying stopped all together. I would definitely recommend this product to anyone! I got a great deal on it and love the fact that it was ready to feed, no more mixing!
EtheleneErbacon, WV

Great Product… interesting pricing!

We have been using this formula for years (currently using for our third child). As far as the product goes we have no complaints. We even loved Amazon’s pricing, although find it “ironic” that they rose the price significantly after our first purchace. The new price is very competitive, but the original was of course outstanding. Hard to complain when you are not being overcharged, but I can’t help being a little dissapointed with sudden increase.
GlyndaHooper Bay, AK

Great price, best I found anywhere when you order auto shipping

This is great stuff. Have baby that cannot use anything else and this price is great and I love auto shipping. I never have to worry about running out.
ElainaNewberg, OR

A Mothers delight and Baby’s aide to a sensitive tummy.

A great aide for baby’s sensitive tummy to milk and a delight for mommy to see her child not getting upset. Price is GOOD TOO!
MelvinDepue, IL


We tried this after the type the hospital gave us gave her fussiness and gas. This formula gave her painful constipation, I can’t put her down because of crying. Hoping new formula clears this up soon. She does get breastmilk but I have supply issues so we supplement.
AraRison, AR

Best thing for early morning feedings

I wish these would last longer than 3 days but they are worth the purchase especially when you can’t keep your eyes open long enough to mix formula with one hand while carrying a crying infant in your other hand! You don’t need to mix water, just shake well and pour. I have the Dr. Brown’s Bottle Warmer and for a 4oz bottle with refrigerated formula, it takes about 3mins to warm up. I spoke to customer service at Similac and they said, although not recommended and should be done only when absolutely necessary, you can keep a prepared bottle out for up to 2 hours if needed.
MaricaBeech Island, SC

Great Product / Bad Design

This product is competitively priced on Amazon — it’s even a little bit cheaper than ordering from the Similac website directly, even with their 15% off discount for first-time orders. Overall, I think the product is great; my son seems to digest it better than the regular milk-based Similac. However, my BIGGEST complaint is that the design of these bottles really really SUCK! First of all, the foil — once it opens, it leaves behind jagged edges (if you use the cap to open the foil). This causes the soy milk to pour unevenly out of the bottle, and creating a huge mess. And…since the foil is sealed so tightly around the mouth of the bottle, it’s impossible to remove it completely. (Once I did try removing the foil completely… only to have foil bits fall into the soy milk. I was lucky to have seen the bits when I poured it into the baby bottle, otherwise it would’ve ended up in my baby’s feed!!) So… instead of using the cap to open the foil, I’ve started using a sharp knife to cut a homemade spout into it – for easier pouring. Unfortunately, this method doesn’t work either, since the milk has to travel over the lip of the bottle, and thus, it spills out all over the place. Again, huge mess. And especially since you’re supposed to shake well before each use, there is milk all over the foil spout as you’re pouring each feed. So yeah…BIG OL’ HUGE MESS!!! Why are these bottles so difficult to pour?!?! Since we’ve started on Similac a few weeks ago, I have NOT had a good pour. With each feeding, enough of milk comes down the side of the baby bottle and the Similac bottle that I’m losing a whole ounce or two every time. Such a waste!! I hope Similac realizes what a horrible design they’ve created and improve the way it pours!!
FloSimpson, KS

great formula

my lil one is lactose and i thought i’d try a different formula. she had not probably adjusting to the taste and i love that it is “ready to feed” and in a bottle that i can reclose. Will buy again if price drops.
KimberliBoothville, LA

Good formula at a great price!

Similac Soy Isomil turned out to be the answer to my son’s eczema…and Amazon had the best price when I needed it!
MaybellBuena Vista, NM

Soy formula

Good for allergic baby as we wean off breastfeeding. Very convenient delivery and pretty good price. Occassionaly you can get it cheaper, on sale at Toys R US, but, Amazon (subscribe and save) has been cheaper than walmart and our local grocery store.
DorianOttawa, IL

Love the product but not Amazons lack of package labels

I love that Amazon has the ship and save option for the Similac Soy. It’s so conveinent and really reduces the stress of having to purchase the formula at the store. However, I am not a fan that the shipping carton doesnt indicate anywhere that the item shouldn’t be left in extreme heat. I had 6 cases of formula delivered to our apartment, just like I do every month. This past month the temperature was 90 degrees or higher, not accounting for the humidity. What I think is unfortunate is that in order to determine if the formula was safe for my baby to drink, due to being left in 90+ degree heat for several hours, I had to call the similac hotline. I didn’t want to take the chance that the formula was bad because then I would have wasted well over a hundred dollars and possibly made my baby sick. As it turns out the formula can be kept at temperatures of 100+ degrees for 24 hours. My ups man had no idea not to leave the shipments on the doorstep instead of checking back the next day or even having me pick up the boxes from their local warehouse because there is no type of warning or notice on the packaging.
MeaganZalma, MO

Formula that works

My son had to switch to the soy due to an intolerance to the regular Similac. He instantly took to this one. Ready to pour could not be any easier- plus the travel size ones are perfect for diaper bag. This is comparable to pricing in the store. You can occasionally find cheaper, but free shipping is so much easier!
KiraBennington, KS