The Eufy S1 Pro Breast Pump Increased My Milk Supply, But Is It Actually Worth It?

At this point in my breastfeeding journey, I feel like I’ve become a breast pump connoisseur. It helps that I exclusively pump, so finding the best breast pump is crucial for me. What does that consist of? It needs to be comfortable, portable, and most importantly, effective. At the beginning of my journey, I used the Momcozy M5 Wearable Pump, and I truly believed there couldn’t possibly be a better pump out there. However, when I discovered the unique features of the eufy S1 Pro and its claim to increase your milk output, I was intrigued. As a new mother who miraculously managed to pump just enough milk to sustain my daughter every day, I wanted to boost my supply slightly so I could build a conservative stash in our freezer. So I tested the eufy S1 Pro Breast Pump for two months before writing this review.

What’s in the box?

Before we get into the nitty-gritty of how the pump worked for me, let’s talk unboxing. As soon as I opened the box, both pumps greeted me, sitting right on top, assembled. However, they did have stickers, so you have to disassemble the pumps to take them off (and wash the parts before use). Underneath all of that was, well, everything else.

The eufy Wearable Breast Pump S1 Pro comes with:

• 3 extra flange sizes in sizes 17 millimeters, 19 millimeters, and 21 millimeters.
• A carrying case with charging port.
• 2 milk collectors.
• 2 built-in heating flanges.
• 2 motors.
• 2 valves.
• Charging cables and manual.

My first impression of the eufy Wearable Breast Pump S1 Pro was that it’s very sleek and surprisingly smaller than the Momcozy I had been using, but holds the same capacity in the milk collectors. I love that it comes with a carrying case that doubles as a charger, which made it easy for me to store and charge on the go. In fact, it proved itself to be incredibly helpful during a four-hour road trip.

Product Features

After already having experience with a portable breast pump, I naturally found myself constantly comparing this breast pump with the Momcozy. While they have similar features, I was thoroughly impressed with the thoughtfulness behind the eufy Breast Pump’s design and features.

Suction levels: The eufy breast pump offers seven suction modes, but, like the Momcozy, you’ll find you only need a couple and will likely stick with that. However, it’s nice to have options. I found my sweet spot is between three and five.

Suction speeds: The pump features three speed modes, slow, medium, and fast.

Rhythm modes: Using the app, you can set specific modes on your pumps. The options are max output, standard, gentle, and natural. Here’s what these options mean in real life:

• Max: This is great for moms who want, well, the max output. This is the one I used every single time. Why wouldn’t I? Gimme that milk. The app shows you that this mode switches between stimulation and expression throughout the session. It will do 1.5 minutes of stimulation, 7 minutes of expression, 1.5 minutes of stimulation, 7 minutes of expression, 1.5 minutes of stimulation, and end with 11.5 minutes of expression.
• Standard: This is ideal for moms who prefer a traditional pump’s rhythm. It does 2 minutes of stimulation and 28 minutes of expression.
• Gentle: For moms who have sensitive nipples. It does 2 minutes of stimulation, 13 minutes of expression, 2 minutes of stimulation, and 13 minutes of expression.
• Natural: This mode will mimic the natural sucking rhythm of a baby. It will do 5 minutes each between stimulation and expression for 30 whole minutes.

Auto shut-off: Like most breast pumps, the eufy is set up to shut off automatically after 30 minutes. However, with the app, you can set a timer as low as 5 minutes up to 30 minutes.

App: While products that use apps are typically the bane of my existence, I did love seeing all the options available. On the app, you can customize your pump’s name (mine is called Beatrice), set up the rhythm, suction, speed, and heating. You can choose one of the specific rhythm modes, and it will use the designated presets for each one, but you can adjust any of the options to tailor your pumps to you. The best part is that it saves your setup, so you never have to go in and change anything if you have one specific preference for your pump sessions.

Heating: This is the most unique feature of the eufy S1 Pro Breast Pump and the entire reason I wanted to test it out. The heating element is what is marketed to help increase your output when using the pump. 

• Temperature: Using the app, you can set the temperature as low as 95ºF and as high as 105ºF. 
• Timer: It also includes a separate timer that ranges from 5 to 20 minutes. However, you can turn it back on after the timer ends if you want.

Testing 

Since my goal with this pump was to increase my output, I decided I needed to use it for a longer period of time than I did with the Momcozy. I wanted to test the eufy S1 Breast Pump in several factors, such as ease of use, comfort, and overall performance. After eight weeks, here are my results.

Ease of Use

Let’s talk about assembling the pump. There are four parts for each pump: the motor, the collector, the silicone suction, and the valve. Easy peasy. Except it’s not. This pump has a pretty impressive seal, but that means it can be a pain to pry open. There are particular instructions on how to remove the motor from the assembled pump, which was a learning curve for me, as the Momcozy had a straightforward method. I also constantly found the valves to be tricky to put in due to the design of the inside of the milk collector. If you have big fingers or limited hand mobility, it may be difficult to assemble your pump. 

Positioning the pump on my breasts was easy—simply align the flange with the center of your nipple to ensure a proper fit. If it feels weird when you turn it on, simply pull the side of your breast to release the suction and readjust. 

Using the pump is another significant learning curve to ensure you are giving it a fair chance at helping increase your output. The app will help you tailor each session to your specific needs. You can use the provided presets (max, standard, natural, and gentle) or create your own based on what works for you. This is also where you will adjust the speed, strength, time, and heat.

The app is very user-friendly once you get your pumps connected. You have the option to label a pump left or right, but I found this unnecessary. Since I have to pump for longer than 30 minutes, it was difficult to track what my output was for each separate breast. Additionally, I follow the pitcher method, which means I dump all of my pumped milk for the day in one jar, so I didn’t track individual pump sessions. I used the max output preset, and the only thing I adjusted was the strength of the suction slightly for the stimulation and expression. 

Cleaning the pumps was an absolute nightmare for me. The valve, suction, and flange are fine—typical of any other pump in my opinion. But the milk collector was another story. It has so many nooks and crannies that it’s truly the worst to clean. I had to use several different tools to ensure it was properly cleaned, or my old milk would get stuck on the walls of the collector. I had used a toothbrush, a bottle brush, and a straw cleaner. At one point, I tried just to use my fingernail. I found that I could never get it completely clean.

Lastly, I tested the wearability and portability of the breast pump. This pump wore well. It’s slightly smaller than the Momcozy, so it’s more discreet. Sometimes my husband couldn’t even tell I was wearing the pumps. The portability is excellent, thanks to its convenient charging case.

Comfort and Fit

Like all pumps, if it’s not comfortable, it’s just not working out. Comfort is a crucial factor in your breast pump because it can help you relax and support your letdown. If you’re uncomfortable in your pump, it could increase your stress and overall milk output for that session. So I had to test not just the comfort while wearing the overall pump, but the comfort of the suction and the overall fit of the standard flange size of 24 millimeters.

Suction Comfort

Comparing again to the Momcozy, the suction comfort was night and day. I wish I could express how much more comfortable the suction was with the eufy than the Momcozy. I found the Momcozy to be very rough on my nipples, even on the lightest settings. There were times I had to actually stop the pump to give my breasts a break from the excessive pulling of my nipples. The eufy was a breath of fresh air. The suction was so gentle that I had forgotten I was wearing the pump on several occasions, and my milk had overflowed. There had never been a time when I dreaded using the eufy because it felt so good to use it. This level of comfort could have been a massive factor in the quality of my output per session.

Wearability Design

As I mentioned already, the wearability of this pump was fantastic. It’s much more discreet, but it also just felt exceptionally comfortable to wear for my uniquely long pumping sessions. For reference, I have to pump for at least an hour due to my very slow letdown. However, since the pump was so comfortable to have on, I didn’t mind. The only thing I will note as a con is that the flange would get a bit slippery from my milk, and if I moved around too much, I found that my milk tends to leak or spill easily.

Flange Fit

I wear the very standard 24-millimeter flange size, which is the one that comes with the eufy. However, it also has three other flange sizes you can place inside the hole of the flange to make it fit your specific nipple size better. I used the 21-millimeter once, not realizing that the actual flange itself was the 24-millimeter I needed. I found it to be comfortable, although it was the wrong size for me.

Performance

Like all pumps, performance will make or break it. It doesn’t matter how comfortable or uncomfortable a pump is; if we can get a good performance, we might just endure anything for that sweet, sweet, liquid gold.

Suction

As I mentioned earlier, the suction of the pump was very gentle on my nipples, despite the power. I love that there are different strengths to choose from, which help make it a very personalized experience. The three and five strength levels worked best for me. There was effective pulling without any pain. In fact, I found most of my nipple soreness from using the Momcozy was healed after switching to just the eufy breast pump.

Noise Level

The Momcozy had a noise level of under 50dB, but I still found it to be jarringly loud. Sometimes I couldn’t even hear my husband speak because it was louder closer to my ears. Comparatively, the eufy is under 46dB, making it much quieter, and you can tell immediately. There were times that the pump was so quiet, I forgot I was wearing it, and other moments when my husband had to confirm they were even on. For reference, 46dB is the equivalent sound comparison to a refrigeration hum or a quiet library. While they are both technically under the same comparison range, I still found the eufy to be significantly quieter than the Momcozy.

Heating

Okay, let’s talk about it. I absolutely love the heating feature…now. But I need to be completely honest here. After the first session using this pump, I was cursing its existence and swore never to use it again. Why? Because I experienced pretty wicked burns on my areola from the heating. It was harrowing, and I could see my raw skin underneath. This was an absolute major concern. I was ready to write an extensive take-down piece on this pump because of this. 

However, once the pain of the burns subsided, I realized it was entirely my fault. The brand warns you not to choose a temperature that is too hot, as there is a risk of burns. In my head, I believed that the hotter it was, the better the output. Since I couldn’t really tell it was burning me, I didn’t realize it was hotter than my skin needed. Once I adjusted it from a balmy 104ºF to a cozy 97ºF, it was a completely different experience. I never dealt with a burn again and still received all the benefits of warming my breasts during each session, which may help with your letdown and overall output.

Milk Output

The pièce de résistance of the performance test: did I see an increase in my output using the eufy S1 Pro Breast Pump? The answer is undoubtedly and unequivocally yes. I could not be any more shocked than I was when I started to see my jar of milk get fuller each day. For reference, before I started using the eufy breast pump, my daily output held very steady around thirty ounces. Considering that’s exactly what my daughter drank a day, I labeled myself a “just enougher.” After using the eufy pump for just a couple of weeks, my supply jumped to a whopping 40-42 ounces a day, with one day as high as 47 ounces. This is an impressive 40% increase in my output. My supply did end up stabilizing around 40 ounces a day for the following six weeks, which would make the output increase 33.3%. This all means that the advertised amount of 30% as a potential milk output increase was successful for me. 

Final Thoughts

While there were a few hiccups in my journey using this pump (sorry, burnt nipples), I couldn’t possibly recommend this pump more. It successfully increased my output, was incredibly comfortable to wear, very quiet, and of course, conveniently portable. The cleaning is a pain, but a price I’m willing to pay to see my milketh overfloweth. I’ve tested over six different pumps now, and this is by far a clear winner for me. If you’re looking for a pump that works with your breasts and stops treating them like every other mom’s chest out there, then this is an investment you won’t regret. Just don’t burn your nipples.