When to pump (and for how long): what the experts really say

Why pump your milk: the "why" defines the "when"

You’ve decided to pump your milk, or you’re thinking about it. And you’re hitting a wall of conflicting information: some say start at 3 weeks, others at 6; some recommend 6 sessions a day, others 10. Forums, websites, apps, advice from friends and family... everyone has an opinion, and they often contradict each other.

What we’re going to do here is different. We’re going to rely on two experts Reflet has worked with directly: Lauriane Emond, an IBCLC-certified lactation consultant who supports mothers daily through the most complex breastfeeding situations, and Marion, product manager at Fizimed, a doctor in neuroscience with training in breastfeeding, who has breastfed for a total of four years and tested dozens of breast pump models.

Before even talking about timing, Lauriane is clear: the first question to ask isn't "when should I pump?" but "why am I pumping?". Because the answer changes everything.

The situations that lead to pumping are all very different:

• Separation from your newborn right from the start (NICU hospitalization, prematurity, inability to nurse in the first few days): this is a lactation emergency. You need to start pumping immediately, using the most effective equipment available.
• Relactation or low milk supply : you want to boost a supply that has dwindled. This is also a situation that requires a very different approach than for a mother who is just pumping to build a stash.
• Induced lactation : mothers who haven't given birth but wish to breastfeed their child (adoption, surrogacy) will induce lactation solely through pumping.
• Returning to work : you want to maintain your milk supply during your hours away and provide your breast milk to your baby during that time.
• Building a stash : breastfeeding is going well, everything is fine, and you just want to have a reserve of breast milk for an outing, an event, or to be prepared.

These five situations call for very different recommendations. That is why there is no universal answer to "when to pump": there is an answer tailored to each context.

First, the hospital-grade breast pump: why it changes everything

Before discussing timing, Lauriane emphasizes a point that dictates everything else: the choice of breast pump.

For starting breastfeeding with a pump, relactation, kickstarting a milk supply, or boosting a supply that is dropping, a hospital-grade breast pump is the only truly effective option. Why? Because its suction power (300 mmHg and above) and cycles (60 to 120 per minute) allow for truly effective drainage, comparable to what a baby does when nursing well at the breast.

A portable, wearable breast pump, even an excellent one like the Emy Pump from Fizimed, is not the tool for starting out. It is a mobility tool, one you use when you need to move around, return to work, or travel. Marion confirms this clearly: Fizimed developed the Emy Pump with power equivalent to hospital models and constant suction for 30 minutes, precisely because the portable pumps on the market did not reach that level. But even then, Lauriane is clear: during the starting or relactation phase, the hospital-grade pump remains the gold standard.

The practical rule they both recommend: start with the hospital-grade pump at home, and use the portable pump when you have no other choice (traveling, working, going out). Many moms have both and combine them intelligently.

How many times to pump per day: Lauriane's number

Lauriane provides a clear benchmark, rooted in the physiology of breastfeeding: 8 times per 24 hours. This number is not arbitrary. It replicates the frequency at which a healthy breastfed baby would nurse. A newborn nurses on average 8 times a day. The breast pump must replicate these 8 stimulations to send the same signal to the brain: "there is a demand, let's produce milk."

This is the fundamental principle of lactation that Marion also reiterates: it is a supply and demand mechanism. The more you stimulate, the more the brain understands that it needs to produce. The less you stimulate, the less it produces. It is as simple and as precise as that. This is why moms who increase the intensity of their pump hoping to get more milk are on the wrong track: it is not intensity that increases production, it is the frequency of stimulation.

Regarding the upper limit, Lauriane clarifies: beyond 9 to 10 sessions, you risk exhausting the mother without any proportional gain in milk production. 8 is therefore the optimal benchmark.

This figure of 8 applies particularly when starting to pump, relactating, or exclusively pumping. For a mother who is breastfeeding well and pumping to build a stash, the frequency is naturally different: the baby's feedings count as stimulation, and pumping is in addition to that.

How long should a pumping session last

Lauriane provides a precise range: 15 to 30 minutes, depending on the mother's let-down reflexes.

The let-down reflex is the moment when the milk "releases" and begins to flow. Some mothers have only one let-down per session, while others have several in succession. When you have multiple let-downs, the session will naturally be longer and more productive. The optimal duration is therefore not fixed: it is based on what the body does.

Marion confirms this from a hardware perspective: the Emy Pump by Fizimed maintains constant power for 30 minutes, precisely because that is the relevant duration for a complete session. She points out that this is an often-overlooked quality criterion: some breast pumps, including hospital-grade models, do not maintain their suction power for 30 minutes. Yet, power that drops mid-session makes the session less effective exactly when the second or third let-down reflex might occur.

Double pumping: the recommended method

Lauriane is very clear on this point: pumping both breasts simultaneously (double pumping) is more effective than pumping one breast after the other.

The biological reason: when a baby nurses on one breast, it triggers the let-down reflex in the other. By pumping both at the same time, you replicate this mechanism. The result: you drain more milk in less time. In practice, a 20-minute double pumping session yields better results than a 20-minute session on each breast separately.

Marion confirms the benefits of double pumping and explains that Fizimed offers its breast pumps at half price when purchasing a second one, precisely because double pumping is the recommended method.

For mothers using a hospital-grade breast pump with an external motor and separate flanges, Lauriane also recommends breast compression during the session : gently massage the breast while the pump is suctioning, alternating in 5-minute phases, to replicate the compression a baby uses with their hands while nursing. This significantly improves drainage.

A second advantage of portable breast pumps for double pumping that Marion highlights: with two portable pumps, you can adjust each side independently. About 75% of women have different milk production levels between their left and right breasts. With a standard hospital-grade pump, the settings are the same for both breasts. With two portable pumps, you can adapt the intensity and mode for each breast separately.

What time of day should you pump

On this point, Lauriane is honest: there is no universally perfect time. Consistency is what matters most. A mother who pumps 8 times a day at times that work for her will get much better results than a mother who tries to optimize every session but misses half of them.

Marion confirms this from her experience with the mothers she supports at Fizimed: the main obstacle isn't finding the optimal time, it's organization. When mothers have the right equipment and a clear pumping schedule, they succeed. When they imagine it's an insurmountable mountain, they give up before even trying. As Marion says: "I thought it was truly insurmountable. And once they're in it, perhaps because they've been supported, because they have the right equipment, because they have their pumping schedule, it actually goes fine."

The only practical nuance both experts highlight: avoid pumping when you are stressed or tense, because stress directly impacts the let-down reflex. Settling into a quiet place, even briefly, makes a real difference in the amount you get.

Pain while pumping: it is never normal

This is a message that both Lauriane and Marion repeat in the Reflet series, and it deserves to be stated clearly: if pumping is painful, it is not normal and you should not have to endure it. We explain all these elements in our series dedicated to breastfeeding Milky Adventure.

The most common cause of pain while pumping: the wrong breast shield size. A breast shield that is too large pulls part of the areola inside, which causes pain and can eventually lead to edema. A breast shield that is too small rubs against the nipple and causes cracks. In both cases, the solution is to change the size, not to grit your teeth.

Lauriane goes even further: the standard breast shield sizes offered in maternity wards (24 mm on average) are often too large for most women, whose nipples are usually around 13 to 15 mm. She recommends measuring your nipple even before giving birth, ideally during the prenatal period, so you arrive at the maternity ward with the right sizes.

Marion confirms the importance of this aspect at Fizimed: the Emy Pump offers six sizes of soft silicone breast shields precisely because one size cannot fit every woman, and may not even fit both breasts of the same woman.

Key takeaways

The Reflet experts' recommendations in summary:

• The "when" depends primarily on the "why": separation, relactation, returning to work, or building a stash. Each situation has its own protocol
• To start or boost milk supply: hospital-grade breast pump, not the portable one
• 8 pumping sessions per 24 hours for starting, relactation, or exclusive pumping, by mimicking the frequency of a baby's feedings
• 15 to 30 minutes per session, depending on your let-down reflexes
• Double pumping (both breasts at the same time) is the most effective method
• Breast compression while pumping improves drainage
• Consistency is more important than perfect timing
• If you feel pain while pumping, seek advice : it is never normal, and the cause is often an ill-fitting breast shield
• To learn more, watch Milky Adventure by creating a free account on Reflet. We share over 2.5 hours of breastfeeding content with concrete, actionable advice