Formula Basics
[Check out Options for Feeding Baby for the pros and cons of breastfeeding, pumping and formula]
Picking a Brand
I reccomend Kendamil and Bobbie, which follow the more organic, European style of having fewer artificial ingredients, but are available here in the US (including at Target)
Don’t bother with the “Organic” version of Kendamil - it’s not meaningfully better, and the can it comes in is way harder to open than the normal version (which actually matters a lot if you are holding a baby in one hand and prepping formula with the other)
HiPP and Holle are popular European brands that you can get shipped to the US; people say they are great for babies with sensitivities to other brands
Personally, I chose a brand (Kendamil) that I knew I could easily get via Instacart pretty much anywhere I traveled in the US, in case something went wrong and I didn’t have enough (flight delay, luggage lost, spilled tin, etc)
Comprehensive comparison spreadsheet with main ingredients here
Some formula brands (HIPP, Similac) also make liquid “ready to feed” bottles in addition to the powder form. This can be useful for travel so you don’t have to worry about prepping a bottle on the go. But for your primary source of formula, powder takes up much less storage space.
Whatever formula you choose, it may take a week or two for baby to adjust - this might manifest as extra irritability
You might be tempted to try a different brand, but give it a little more time and they will likely get used to it
Obviously if they are having more of an allergic reaction (e.g. itchiness, swelling, vomiting, diarrhea), that’s a different scenario and you should stop using that formula!
Introducing Formula
As discussed in Options for Feeding Baby, while some people do exclusive breastfeeding or exclusive formula, many others do “combination feeding” - feeding both breastmilk and formula, and over time phasing out of breastmilk (e.g. once back at work).
Even just doing one formula bottle a day can really take the pressure off you to be their sole source of nutrition - and it means less stress if you’re not home in time to nurse, pumped milk spills, etc since you have an alternative
The biggest downside of formula is it doesn’t contain the antibodies that help babies fight illness. So if you’re able, try keeping up at least one nursing/pumping session to continue to get some of the immune benefits of breastmilk (especially if baby is under 6 months).
Introducing formula to a breastfed baby can sometimes cause gas, so do it gradually starting with just one feed each day. You can even split that feed in half and give a breastmilk bottle first and then a formula bottle.
For the very first introduction, do it during the daytime so you can monitor for an allergic reaction.
Guidelines for Serving
In choosing which bottles to use, I’d strongly consider glass or silicone bottles over plastic - recent research suggests that an unhealthy amount of microplastics are released when babies are fed formula in plastic bottles, due to the hot water added, the shaking to mix, and the sterilizing of bottles (paper)
You can add a silicone sleeve to prevent glass bottles from breaking
In March 2025, the Chicco Duo bottles should be back in stock - these brilliantly use glass on the inside and plastic on the outside
Every formula brand has its own directions and “scoops to water” proportions so read it carefully
I recommend mixing formula with fluoride-free water, as there is some evidence that fluoride intake during infancy can have a negative impact on neurodevelopment. Most tap water systems in the US add fluoride to the water (especially in cities), so look up your county’s fluoridation status. You can read more about this issue here.
You can buy bottled water, or for a longer-term solution, have a plumber install a reverse osmosis filter under your sink. Fluoridated water may also have a small, negative impact during pregnancy, so if you plan to have more babies, it might be a worthwhile investment.
Regular water filters don’t remove fluoride, and neither does boiling the water
If it’s a European brand, such as Kendamil or HiPP, they are legally required to say that the water must be boiled and cooled before use. You don’t actually have to follow that extremely inconvenient instruction if you have clean water and a generally healthy baby.
As your baby grows, the amount of formula they need per feeding will increase by about 1 oz per month, until leveling off around 6 months at 6-8 oz per feeding
This is different than breastmilk, where babies often maintain a similar serving size even as they grow, the milk composition just gets more protein rich
According to the official guidelines, you should use a bottle within 2 hours of preparing it and 1 hour after feeding begins. I don’t think you need to follow these rules super strictly - research actually suggests the concerns about bacteria growth are overblown, and you’ll avoid wasting lots of milk. If you refrigerate formula immediately upon preparation, it’s good for 24 hours.
The ledge on the formula tin is for resting the scooper so that you don’t have to reach in and potentially contaminate the formula. Use this ledge to level off your formula scoop before putting in the bottle (instead of having to use a separate knife). This may be obvious to some, but I didn’t realize it immediately!
Formula smell on clothes can really stink, so invest in many bibs and be prepared to do lots of laundry
I also recommend quickly rinsing used bottles out immediately, even you don’t fully wash the bottles until many hours later, because it helps prevent the bottles from acquiring a gross smell
Helpful Gear
Formula dispenser (with up to 4 servings) - useful for a long travel day, or could just use a subset for a shorter excursion or to have a night feed already measured out
Baby Brew: portable, battery-powered bottle warmer if baby needs it warm while you’re out or traveling
Prepare a whole day’s batch in a pitcher in the morning, so you don’t have to continue to measure out throughout the day (it’s good for 24 hours in the fridge)
Baby Brezza is formula prep machine that automatically dispenses and mixes the right amount of water and formula and warms it to the right temperature. Some people swear by it, especially for night feeds, others don’t think it’s worth the cost/counterspace (and it takes some effort to clean).
