How Do I Know If My Baby Needs Similac Alimentum?

Learn how to figure out if your baby would benefit from Alimentum, plus everything you need to know about switching formulas.

Similac Alimentum is a special type of baby formula found in the purple can. If traditional formula causes baby to develop GI symptoms because of an allergy or intolerance to milk, Alimentum may help bring relief, while still supplying all of the vitamins and proteins baby needs. It is one of the specialty formulas most commonly recommended by doctors.

Today, we’ll cover how to figure out if your baby would benefit from Alimentum, plus everything you need to know about switching formulas.

What is Alimentum used for?

Similac Alimentum is a specialty formula (or hypoallergenic formula) designed for babies who have trouble digesting traditional cow's milk-based formula.

It is meant to help babies who have a milk allergy, milk intolerance, reflux, or colic --- all conditions that make it harder for baby to digest the cow's milk proteins.

Alimentum still contains cow's milk proteins, but these proteins are broken down so they're easier to digest. Plus, Alimentum is also lactose-free.

This way, the formula won't cause a milk-sensitive baby to develop GI symptoms like regular formula does. The formula is also meant to help build up baby's tolerance of cow's milk proteins.

Once baby switches from a standard formula to Alimentum, the symptoms that the standard formula caused should go away within 24-48 hours.

Baby Formula Expert Dr. Bridget Young compares Alimentum to Nutramigen and two other hydrolyzed formulas:

How can I tell if Alimentum would help my baby?

If they show symptoms of a milk allergy while consuming formula

Milk allergies always involve the immune system. Normally, our immune systems protect our bodies from foreign invaders like bacteria and viruses. But when a baby has a milk allergy, their immune system treats the proteins in milk like foreign invaders to the body, and triggers symptoms of an allergic reaction to defend the body against these proteins.

There are two types of milk allergies --- immediate-type and delayed-type.

Symptoms of immediate-type milk allergies develop seconds to hours after milk is consumed. The most common of these symptoms include hives, vomiting, congestion, and swelling. (For more, read our complete guide to allergic reaction symptoms).

Symptoms of delayed-type milk allergies develop hours to days after milk is consumed. These symptoms almost always involve the GI tract, and may include diarrhea, loose or abnormal stools, vomiting, stomach and abdominal pain, reflux-like symptoms, and colicky (inconsolable) crying. (For more, read our guide to delayed-type food allergies.)

If they show symptoms of a milk intolerance while consuming formula

Milk intolerances don't involve the immune system, but are digestive-based. They happen when baby's digestive system has trouble breaking down parts of cow's milk.

  • The most common is lactose intolerance, which happens when baby doesn't have enough of the lactase enzyme to digest lactose (the sugar in milk).
  • Baby could also have an intolerance to the proteins in milk.

Milk intolerances produce GI symptoms that may include:

  • Diarrhea
  • Loose stools
  • Gas
  • Colic
  • Bloating
  • Stomach aches and pains
  • Constipation
  • Abdominal pain/cramps
  • Nausea
  • Vomiting
  • Bloody or mucousy stools
  • Excessive spitting up
  • Irritability after having dairy

The symptoms are similar to those of delayed-type milk allergies, but milk intolerances are far more common than delayed-type allergies.

If you think your baby has a milk allergy or intolerance, talk to your pediatrician about possibly switching baby's formula to Alimentum.

Will Alimentum help with colic or reflux?

Yes, Alimentum is designed for babies with colic or acid reflux. In fact, reflux-like symptoms and colicky crying can often be symptoms of a milk allergy or intolerance, and Alimentum is helpful for babies with these sensitivities.

Alimentum isn't necessary if baby has normal reflux (aka normal patterns of spit-up). But if baby has acid reflux (also known as gastroesophageal reflux disease or GERD), Alimentum is beneficial.

For more on identifying if your baby has acid reflux or colic, please read our linked articles.

What else should you know before choosing Alimentum?

Although Alimentum is very beneficial for cow's milk-sensitive babies, it is also very expensive --- at least double, or triple, the price of standard formula.

Since there are other specialty formulas available (including generic versions), it might be worth it to try a less expensive specialty formula before trying Alimentum.

Still, insurance may be able to help you afford Alimentum. Your pediatrician may be able to help you determine if your health insurance will cover the cost of Alimentum. If your insurance company is only willing to pay for formula that’s deemed medically necessary, your pediatrician may also write baby a prescription for Alimentum. That way, insurance can tell the Alimentum is medically necessary for baby, and will pay for the formula.

Alimentum is also approved for the WIC program, so be sure to look into this if you're eligible (or think you may be eligible).

Trying to decide whether Alimentum or Nutramigen is the best choice for baby? Our comparison will help you decide.

Can I mix Alimentum with standard formula?

It is perfectly safe to mix Alimentum with standard formula, and it's even necessary to do so when you first switch over baby's formula to Alimentum. (This will help get baby used to the formula; more on this below.)

But once the formula switch is complete, if you are considering mixing, you'll need to give baby enough Alimentum to relieve their symptoms. Mixing in regular formula might make this tougher.

After all, while Alimentum has the milk proteins broken down, standard formula has the proteins still intact. And the intact proteins in the standard formula might lessen (or possibly remove) the benefits of the Alimentum.

How to switch formulas: Switching to Alimentum

When switching baby’s formula, it's important to remember that Alimentum tastes different than traditional formula or breastmilk. Alimentum is not as sweet, so it may take some time for baby to get used to the new taste.

So, if you've decided to switch over to Alimentum, you'll want to introduce it gradually.

That way, baby gets used to the new taste (and is less likely to refuse the bottle).

You'll do this by mixing Alimentum with baby's current formula for a few days.

Try this sample schedule:

  • Day One: 75% previous formula, 25% Alimentum
  • Day Two: 50% previous formula, 50% Alimentum
  • Day Three: 25% previous formula, 75% Alimentum
  • Day Four: 100% Alimentum

If baby still refuses the bottle as you switch to Alimentum, our article on bottle refusal offers useful tips for overcoming this.

When can I switch back to a standard formula? 

Can you successfully switch back to standard formula after using Alimentum? If so, when? The answer depends on what your doctor recommends and what type of sensitivity your baby has to milk.

Many babies with suspected milk allergies really only have milk intolerances. And it's safe to reintroduce a standard formula to a baby with a milk intolerance.

Given this, doctors typically recommend reintroducing cow's milk to babies with milk intolerance at some point. The same goes for reintroducing formula where the cow's milk protein is not broken down. So, ask your doctor about when you should reintroduce baby to regular milk-based formula.

Usually, babies with delayed-type milk allergies can be safely reintroduced to regular formula as well, so talk to your doctor about when to switch back if your baby only has GI symptoms from milk.

But if your baby has a confirmed, immediate-type milk allergy, they cannot be safely introduced to standard formula that contains intact milk proteins --- they’re still very much at risk for an allergic reaction from this type of formula. (If you think your baby has an immediate type milk allergy, you will need allergy testing to confirm this.)

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All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.  If your infant has severe eczema, check with your infant’s healthcare provider before feeding foods containing ground peanuts.