One of the most common concerns nurses hear from breastfeeding patients is, “I think my milk supply is dropping.”
Sometimes those concerns are well founded. Other times, what appears to be a sudden decline in milk production reflects a normal change in lactation or a shift in feeding patterns, pumping routines, maternal health, or medication use.
Distinguishing perceived low milk supply from clinically significant reductions in milk production is an important part of breastfeeding assessment. Early evaluation can identify modifiable factors, reassure families experiencing normal changes, and help ensure that infants with inadequate milk intake receive timely support.
Milk production is a complex physiologic process influenced by frequent and effective milk removal, hormonal regulation, maternal health, medications, and breastfeeding management. The Academy of Breastfeeding Medicine recommends identifying and addressing underlying causes before turning to medications or herbal products intended to increase milk production.
For nurses, who often serve as a first point of contact for breastfeeding concerns in hospitals, pediatric and obstetric practices, outpatient clinics, and community settings, understanding those potential causes can help guide assessment and determine when additional evaluation is needed.
Is It Really Low Milk Supply?
Before investigating why milk production may be declining, nurses should first determine whether it has actually decreased.
Many breastfeeding parents interpret softer breasts, shorter feeding sessions, or lower pumping volumes as signs that their milk is “drying up.” As lactation becomes established, effective and regular milk removal plays an increasingly important role in maintaining production. Breasts may feel less full, while infants often become more efficient at feeding and can remove adequate milk in less time.
Pumping output can also fluctuate based on the time of day, recent feedings, pump performance, flange fit, and the individual response to pumping. An infant may remove milk more effectively than a breast pump, making the amount expressed during a single pumping session an imperfect measure of overall supply.
What matters more is the broader clinical picture.
Signs that an infant may not be receiving adequate milk include:
- Poor or slowed weight gain
- Fewer wet or dirty diapers than expected for age
- Persistent signs of hunger after most feedings
- Lethargy or excessive sleepiness during feeds
- Difficulty maintaining effective feeding sessions
When these signs are present, breastfeeding effectiveness and infant growth warrant further assessment. If an infant is gaining weight appropriately, producing adequate wet and dirty diapers, and appears satisfied after feedings, reassurance and education about normal lactation changes may be all that is needed.
Less Frequent or Ineffective Milk Removal
When milk supply has truly declined, one of the first places to look is how often and how effectively milk is being removed.
Milk production largely responds to demand. Frequent, effective milk removal supports continued production, while longer or more frequent periods of milk remaining in the breast can gradually signal the body to produce less.
Changes can occur for ordinary reasons. A patient returns to work. An infant begins sleeping longer overnight. Pumping sessions are missed. Family schedules change. Complementary foods are introduced. Over time, fewer opportunities for milk removal may translate into lower production.
Effectiveness matters as much as frequency. A baby may nurse regularly without transferring milk efficiently. Poor latch, shallow attachment, ineffective suckling, or positioning challenges can limit milk transfer even when the infant spends considerable time at the breast.
Nurses should therefore consider what happens during a feeding, not simply how often or how long the infant nurses.
Pump Problems Can Look Like Supply Problems
For patients who pump regularly, declining output may originate with the equipment rather than milk production.
Potential problems include:
- Incorrect flange size
- Worn valves, membranes, or tubing
- Inadequate suction
- A malfunctioning pump
- Pump settings that do not effectively stimulate milk ejection
Patients may assume their bodies are producing less milk when worn components or poor pump fit are actually reducing the amount expressed. Reviewing pump fit, function, and maintenance can therefore be an important part of assessing an apparent decline.
Supplementation and Schedule Changes
Formula or donor milk may be medically necessary in some circumstances, but when supplementation replaces breastfeeding without corresponding pumping or breast stimulation, milk production may decrease.
Abrupt schedule changes can have a similar effect. Returning to work without a pumping plan, extended separation from the infant, maternal or infant illness, hospitalization, or rapid weaning can all reduce opportunities for milk removal.
If continued breastfeeding is a goal, nurses can help patients understand how these changes may affect production and identify strategies for maintaining appropriate breast stimulation.
A Nursing Assessment Should Look Beyond Milk Volume
When a patient reports declining milk supply, the amount collected during a pumping session is only one piece of information.
A useful lactation history should consider:
- Feeding frequency over 24 hoursP
- Pumping frequency and duration
- Recent changes in work, sleep, or feeding schedules
- Changes in overnight feedings or pumping
- Latch and effectiveness of milk transfer
- Formula or donor milk supplementation
- Pump type, flange fit, and equipment performance
- Infant weight trajectory
- Wet and dirty diaper output
- Infant behavior during and after feeding
This assessment can help distinguish true low milk production from problems involving milk transfer, pumping, or normal changes in lactation.
Maternal Health and Hormonal Changes Can Affect Milk Production
If feeding and milk removal appear adequate, maternal health deserves closer attention.
Acute illness, hormonal changes, underlying medical conditions, and postpartum complications may affect lactation directly or make it more difficult to maintain a consistent feeding or pumping routine.
Illness, Fatigue, and Recovery
Patients who develop an illness, require hospitalization, experience significant pain, or recover from surgery may nurse or pump less frequently because they feel unwell. Hospitalization may also separate a breastfeeding parent from the infant and interrupt regular milk removal.
Severe sleep deprivation, physical exhaustion, and difficult postpartum recovery can create similar challenges. These factors do not necessarily suppress milk production directly, but they may make the routines necessary to maintain supply harder to sustain.
Nutrition and Hydration Matter, but More Isn’t Always Better
Patients frequently ask whether drinking more water or eating certain foods will increase milk production.
Adequate nutrition and hydration are important to maternal health during breastfeeding, and significant caloric restriction, dehydration, or poor nutritional intake may create problems. But consuming excessive amounts of water or particular foods has not been shown to increase milk production in otherwise healthy, well-nourished individuals reliably.
Nurses can help patients focus on adequate nutrition and hydration while avoiding common myths that promise a simple dietary solution to low supply.
Stress and Milk Ejection
Stress is also frequently blamed for declining milk supply, but the relationship is more nuanced.
Stress, anxiety, pain, and emotional distress may temporarily interfere with the milk ejection reflex, making milk more difficult to express during nursing or pumping. Patients may interpret lower pumping volumes or an infant’s frustration at the breast as evidence that production has suddenly fallen.
Stress may also contribute indirectly through missed feedings, shorter pumping sessions, fatigue, or disrupted routines. Helping patients understand that distinction can reduce unnecessary guilt while directing attention toward practical factors that may be addressed.
Hormonal and Medical Conditions May Require Evaluation
Persistent low milk supply despite frequent and effective milk removal may point to an underlying medical issue.
Potential contributing factors include:
- Thyroid disorders, particularly untreated hypothyroidism
- Polycystic ovary syndrome (PCOS)
- Diabetes or insulin resistance
- Significant postpartum hemorrhage
- Retained placental tissue
- Anemia
- Previous breast surgery affecting milk-producing tissue or nerves
- Insufficient glandular tissue
- Pregnancy during an ongoing breastfeeding relationship
- Mastitis or other inflammatory breast conditions
Some patients also report temporary fluctuations in milk production around the return of menstruation.
When milk production remains low despite appropriate breastfeeding management, nurses should consider whether symptoms or history warrant evaluation by an obstetric provider, primary care clinician, pediatric clinician, or International Board Certified Lactation Consultant (IBCLC).
Could a Medication Be Affecting Milk Supply?
When feeding patterns and maternal health do not fully explain a change in milk supply, medication use is another important part of the assessment. A new prescription, over-the-counter medication, hormonal contraceptive, or other product may coincide with a change in milk production.
Certain medications have been associated with reduced milk production or changes in lactation, but the relationship is rarely straightforward. Effects can depend on the specific drug, dose, timing postpartum, duration of treatment, stage of lactation, and individual response. The condition being treated may also influence breastfeeding.
For nurses, the question is not simply whether a medication appears on a list of drugs associated with decreased supply. The larger clinical question is whether medication use may be contributing to the change and how the patient’s treatment needs can be supported alongside breastfeeding goals.
Oral Decongestants
Products containing pseudoephedrine, a common oral decongestant, may reduce milk production in some breastfeeding patients. In a small study cited by LactMed, a single 60-mg dose was associated with a mean 24% decrease in milk production over the following 24 hours. Individual responses vary, but recent pseudoephedrine use is worth considering when evaluating an unexpected decline in supply.
Hormonal Contraception
Birth control is another frequent source of questions during the postpartum period.
Combined hormonal contraceptives containing estrogen and progestin have raised concerns about possible effects on lactation, particularly when initiated early postpartum. Evidence regarding their effect on breastfeeding outcomes is mixed, and postpartum timing is also important because of other maternal safety considerations. Progestin-only methods are generally more compatible with early postpartum breastfeeding, although contraceptive decisions should be individualized.
Contraceptive counseling should therefore consider breastfeeding goals alongside medical history, postpartum timing, and the need for effective contraception.
Certain Psychiatric Medications
Medications that reduce prolactin may interfere with milk production in some patients.
LactMed, for example, notes that aripiprazole can lower serum prolactin in a dose-related manner and has been associated with reports of decreased milk supply or lactation cessation.
That does not mean patients should stop psychiatric treatment because they are breastfeeding. Untreated mental health conditions can carry significant risks for both parent and infant, making coordination with the prescribing clinician essential.
Diuretics and Hormonal Therapies
Intense diuresis with high-dose diuretic therapy has historically been used as part of regimens intended to suppress lactation, although the contribution of the diuretic itself is uncertain. Effects vary by medication and dose, and lower therapeutic doses of some diuretics have not been shown to suppress lactation.
Some hormonal treatments and medications intentionally used to suppress lactation may also decrease milk production. As with other drugs, the potential effect depends on the medication, dose, treatment duration, timing, and individual patient.
Look Beyond the Medication
Timing alone does not prove that a medication caused a change in milk supply.
A patient taking an over-the-counter cold medication, for example, may also be ill, sleeping poorly, dehydrated, or nursing less frequently. Someone beginning contraception may simultaneously be returning to work or changing feeding schedules.
Examining the entire clinical picture helps nurses avoid attributing every change in milk production to a medication while still recognizing medication effects when they are plausible.
Most importantly, a possible effect on milk supply does not automatically make a medication inappropriate.
Treatment for depression, hypertension, thyroid disease, asthma, or another medical condition may be essential. Alternative therapies may sometimes be available, but medication changes should be made in collaboration with the prescribing clinician rather than by stopping treatment without guidance.
Herbs and Supplements Are Not Automatically Harmless
Patients concerned about low supply may also turn to teas, cookies, powders, gummies, and herbal supplements marketed to increase milk production.
Common ingredients include:
- Fenugreek
- Blessed thistle
- Fennel
- Goat’s rue
- Combination herbal blends
Although some herbal galactagogues have a long history of traditional use, evidence supporting their effectiveness remains limited. The Academy of Breastfeeding Medicine recommends evaluating modifiable causes of low supply and relevant medical factors before turning to herbal or prescription galactagogues.
“Natural” also does not mean risk-free. Herbal products can cause side effects or allergic reactions, interact with medications, and vary in quality and concentration. Unlike prescription drugs, dietary supplements generally do not undergo FDA premarket approval for safety and effectiveness.
For nurses, asking specifically about supplements is therefore an important part of medication reconciliation and lactation assessment.
When Patients Should Seek Additional Evaluation
Many milk-supply concerns can be addressed by identifying normal lactation changes or correcting problems with feeding, milk transfer, or pumping. Others require additional clinical evaluation.
Patients should be referred or evaluated when:
- The infant is not gaining weight appropriately.
- Wet or dirty diaper output declines.
- The infant is unusually sleepy, difficult to wake for feedings, or consistently appears unsatisfied after nursing.
- Breastfeeding is persistently painful or milk transfer appears ineffective.
- Milk supply drops sharply and remains low despite frequent and effective milk removal.
- Fever, breast redness, swelling, or worsening pain develops.
- A significant decline follows a medication or hormonal contraceptive change.
- Symptoms suggest thyroid disease, anemia, pregnancy, retained placental tissue, or another underlying condition.
- The patient is considering stopping medically necessary treatment because of concerns about breastfeeding.
Depending on the circumstances, care may involve the patient’s obstetric or primary care clinician, the infant’s pediatric clinician, a pharmacist, and an IBCLC.
Nurses Can Help Find the Cause Before Reaching for a Solution
When patients ask how to increase breast milk supply, the most useful first step may not be recommending a food, supplement, medication, or more aggressive pumping schedule. It may be determining why milk production appears to have changed in the first place.
That requires looking at the infant’s growth and intake, feeding effectiveness, pumping patterns, maternal health, hormonal factors, medications, supplements, and recent changes in routine.
For nurses, that broader assessment can help separate normal lactation changes from problems that require intervention while preventing patients from abandoning breastfeeding or medically necessary treatment based on incomplete information.
Clinical Resource for Medication and Lactation Questions
Medication-related lactation questions can be particularly challenging because determining whether a drug is compatible with breastfeeding is not always the same as determining whether it could affect milk production.
Hale’s Medications & Mothers’ Milk 2025-2026 provides evidence-based information on 1,300 drugs, diseases, vaccines, and syndromes encountered during breastfeeding. The reference includes lactation risk categories, pharmacology information, and clinical guidance to help nurses and other healthcare professionals evaluate medication use while balancing maternal treatment needs, infant exposure, and breastfeeding goals.
Whether assessing a new prescription, answering questions about birth control or cold medicine, or considering whether a medication could be contributing to declining milk supply, nurses can use Hale’s to review the available evidence and support informed clinical decision-making.
Before recommending that a patient discontinue a medication or begin a product intended to increase milk supply, review the available lactation evidence and coordinate care with the prescribing clinician.
Explore Hale’s Medications & Mothers’ Milk 2025-2026 for current, evidence-based guidance on medication use during breastfeeding.
