Similac 360 vs. Kirkland ProCare

Not identical, but nutritionally very close. Kirkland Signature ProCare and Similac 360 Total Care both meet the same FDA nutritional requirements under 21 CFR 107, contain the same core ingredients (nonfat milk, whey, lactose, DHA, ARA), and support healthy growth. The main differences are Similac's proprietary 2'-FL HMO, its palm-olein-free fat blend, and brand marketing — not the base nutrition.

The FDA requires every infant formula sold in the U.S. to meet minimum and maximum levels for 29 nutrients. Kirkland ProCare passes the same regulatory bar as Similac 360 Total Care. The genuine differences come down to Similac's 2'-FL HMO prebiotic, its palm-free fat source, and its brand ecosystem (hospital samples, pediatrician relationships, marketing). Whether those extras are worth the 40–50% price premium is the real question this guide addresses.

Kirkland Signature ProCare infant formula is manufactured by Perrigo Company, the largest store-brand infant formula producer in the United States. Perrigo makes formula in FDA-inspected U.S. facilities and also manufactures Parent's Choice (Walmart), Up & Up (Target), and Member's Mark (Sam's Club) — meaning Kirkland shares its production lineage with most major store-brand formulas.

This is not a discount knock-off. Perrigo has been making infant formula for decades and produces more store-brand infant formula cans than any other U.S. manufacturer. Every can of Kirkland ProCare is made to the same FDA requirements as every can of Similac 360 Total Care. The difference you're paying for with the name-brand isn't safety or manufacturing rigor — it's the 2'-FL HMO, the palm-free fat blend, and marketing overhead.

For a broader look at how formula fits into feeding at every age, see our baby feeding chart.

There are two genuine differences worth understanding: the proprietary additions and the fat source.

2'-FL HMO: Similac's headline ingredient

Similac 360 Total Care includes 2'-FL HMO (2'-fucosyllactose), a human milk oligosaccharide that acts as a prebiotic supporting gut health and immune function. This is a real component of breast milk, and early research is promising. However, the evidence that adding isolated HMO to formula produces measurable long-term benefits in healthy babies is still limited — most studies are short-term and manufacturer-funded.

Kirkland's formula does not include HMO. This does not mean it is nutritionally incomplete — it means it lacks one specific bioactive addition that Similac markets heavily.

Fat source: palm olein vs. no palm olein

Kirkland uses palm olein oil in its fat blend. Similac does not, and markets this distinction prominently. Some research suggests palm olein can form calcium soaps in the gut, potentially leading to firmer stools and slightly reduced calcium absorption. A meta-analysis in Food and Nutrition Research found a modest effect on stool consistency. However, no major health organization has recommended against palm olein in infant formula.

If your baby tends toward constipation, the fat source difference may be worth considering. For most babies, it will not be noticeable.

Here is what the formula industry does not advertise: the FDA requires every infant formula sold in the United States to meet identical base nutritional standards. The $15-per-can difference between Similac and Kirkland is not a safety gap — it is a branding gap.

Similac spends hundreds of millions of dollars annually on marketing, hospital distribution contracts, and pediatrician relationships. When you received a Similac sample at the hospital, that was a business deal between Abbott and the hospital — not a clinical recommendation. Kirkland does not have hospital contracts or television commercials. Those costs are not in your can.

The proprietary ingredients Similac adds (2'-FL HMO) represent a small fraction of the overall formulation. The base nutrition — the protein, fat, carbohydrates, vitamins, and minerals that actually feed your baby — is equivalent. The AAP does not recommend name-brand formula over store-brand formula.

None of this means Similac is a bad choice. It is an excellent formula. It means Kirkland is also an excellent formula, and you should not feel guilty about choosing the cheaper option.

Beyond the ingredient label, there are practical differences parents notice.

Taste: Similac and Kirkland taste slightly different. Babies can have a preference, especially if they have been on one brand for weeks. If you are switching, most babies adjust within a few days.

Mixing: Both dissolve reasonably well in room-temperature water. Some parents report Kirkland powder is slightly grainier, though this varies by batch. A formula pitcher or vigorous shaking resolves any clumping.

Packaging: Kirkland comes in larger tubs (34 oz vs. Similac's 20.6 oz), which means fewer trips to the store. The larger format also contributes to the lower per-ounce cost.

Availability: The main trade-off with Kirkland is that you need a Costco membership and access to a Costco store or Costco.com. If your nearest Costco is an hour away, the convenience factor may not work for your family. Similac is available at virtually every grocery store and pharmacy.

If you are doing combination feeding with breast milk and formula, either brand works equally well.

Switching from Similac to Kirkland (or vice versa) should not require a doctor's visit for most healthy babies. However, contact your pediatrician if your baby shows signs of formula intolerance after switching.

Kirkland Signature ProCare meets the same FDA nutritional standards as Similac 360 Total Care and costs 40–50% less. The base nutrition is equivalent. The main things you give up are Similac's 2'-FL HMO and the palm-olein-free fat blend — neither of which has been shown to produce meaningfully different outcomes in healthy babies.

Choose Similac if: you want the HMO prebiotic addition, your baby has been doing well on it and you see no reason to switch, you prefer a palm-olein-free formula, or you do not have convenient access to Costco.

Choose Kirkland if: you want to save $60–80 per month without compromising on FDA-regulated nutrition, you have a Costco membership, and your baby has no specific tolerance issues that require a specialty formula.

Either works well if: your baby is healthy, full-term, and growing normally. The AAP does not recommend one over the other.

If you switch to Kirkland, give it 1–2 weeks and track what you see. Most babies adjust without any issues — but if something changes, you'll want a record. Tinylog lets you log bottles, note fussiness or stool changes, and see the full picture in one place. Free to try, takes about 10 seconds per feed.

Once you've chosen your formula, sign up for free recall alerts so you'll know immediately if it's ever recalled.

If you decide to stick with the name brands, Similac 360 Total Care Baby Formula and Enfamil NeuroPro Baby Formula are both available on Amazon — Kirkland remains exclusive to Costco members.

For more store-brand comparisons, see our guides on Enfamil vs. Kirkland and cheapest baby formulas. For the name-brand head-to-head, see Enfamil vs. Similac.

• Best Baby Formulas 2026 — An evidence-based guide

• Kirkland vs. Name Brand — Is generic formula really the same

• Cheapest Formulas — Options that meet every nutritional standard

• U.S. Food and Drug Administration. "21 CFR Part 107 — Infant Formula." Code of Federal Regulations.
• American Academy of Pediatrics. "Choosing an Infant Formula." HealthyChildren.org, 2024.
• Alarcon PA, et al. "Effect of individual fatty acids on calcium absorption in infant formulas." Food and Nutrition Research, 2017.
• Marriage BJ, et al. "Infants fed a lower calorie formula with 2'-FL show growth and 2'-FL uptake similar to breastfed infants." Journal of Pediatric Gastroenterology and Nutrition, 2015.
• U.S. FDA. "Infant Formula Guidance Documents and Regulatory Information." fda.gov, 2023.
• Perrigo Company. "Infant Formula Manufacturing." perrigo.com, 2025.

This guide is for informational purposes only and is not a substitute for professional medical advice. Formula recommendations should be discussed with your pediatrician, especially for babies with allergies, reflux, or other medical conditions.