Reglan (metoclopramide) typically begins increasing milk production within 2 to 5 days, with most mothers noticing a meaningful difference within the first week. The medication can boost milk volume by 66 to 100 percent at its peak, though individual results vary considerably.
How Quickly Reglan Works
Reglan increases milk supply by blocking dopamine, a brain chemical that normally keeps the milk-producing hormone prolactin in check. When dopamine is suppressed, prolactin levels rise, and the breasts respond by making more milk. This process starts relatively quickly compared to herbal galactagogues.
Most mothers see results within 2 to 5 days of starting treatment, taken three times daily. In one study of 32 mothers, daily milk production rose by an average of 28.5 percent, going from roughly 380 mL to 690 mL per day. About 78 percent of mothers in that study produced enough milk to fully meet their infant’s calorie and fluid needs. The remaining 22 percent saw some improvement but not enough to eliminate supplementation entirely.
If you haven’t noticed any change after a full week, that’s worth discussing with your prescriber. The medication either works relatively fast or it doesn’t work well for a given individual.
What Affects Your Results
Reglan works best when paired with frequent milk removal, whether through breastfeeding or pumping. The medication raises your prolactin levels, but your body still needs the physical signal of milk being drawn from the breast to sustain and build supply. Taking Reglan while pumping infrequently is like pressing the gas pedal without releasing the brake.
Timing also matters. Mothers who start the medication earlier in the postpartum period, while prolactin receptors are still highly active, tend to see stronger responses than those who begin weeks or months after delivery. That said, even late starters can benefit. The consistency of dosing matters too: taking it three times a day at regular intervals keeps prolactin levels elevated rather than letting them spike and dip.
How Long You Can Safely Take It
The FDA places a boxed warning on Reglan, its strongest safety alert, advising against use beyond 12 weeks. The concern is tardive dyskinesia, a movement disorder involving involuntary muscle movements of the face, tongue, or limbs. This condition can be irreversible, and the risk increases with longer treatment and higher total doses. There is no established treatment for tardive dyskinesia once it develops.
Most prescribers keep courses significantly shorter than 12 weeks, often in the range of 2 to 4 weeks. The goal is to use the medication as a jumpstart while you build supply through breastfeeding or pumping, then taper off gradually. Stopping abruptly can cause a sudden drop in milk production, so a slow step-down over several days helps your body adjust and maintain the gains you’ve made.
Side Effects to Watch For
Reglan crosses into the central nervous system, which is why its side effect profile extends well beyond the digestive symptoms it was originally designed to treat. The most important risk for postpartum mothers involves mood changes. Depressive symptoms, anxiety, panic attacks, agitation, and restlessness have all been reported. Data from a Dutch national reporting database found that pregnant and postpartum women reported depressive symptoms with metoclopramide at a significantly higher rate than non-pregnant women. In one-third of those pregnancy-related cases, suicidal thoughts were also reported.
This doesn’t mean depression is inevitable, but it does mean you should pay close attention to your mood while taking Reglan, especially since the postpartum period already carries elevated risk for mood disorders. Fatigue, headache, and restlessness are more common, less severe side effects. If you notice a shift in your emotional state, even a subtle one, bring it up with your provider promptly rather than waiting to see if it passes.
Is It Safe for Your Baby?
Metoclopramide does pass into breast milk, but in small amounts. It rarely causes problems in nursing infants. Occasional mild effects have been reported, including trapped gas, loose stools, or unusual sleepiness. If your baby suddenly feeds poorly, seems excessively drowsy, or develops digestive changes after you start the medication, that’s worth flagging to your pediatrician or midwife.
How Reglan Compares to Domperidone
Domperidone is the other commonly prescribed medication for low milk supply. In a randomized trial comparing the two at the same dose (10 mg three times daily for 10 days), domperidone produced a 96.3 percent increase in milk volume versus 93.7 percent for metoclopramide. The difference in milk output was not statistically significant, meaning both medications work about equally well.
Where they do differ is side effects. Seven mothers on metoclopramide reported side effects compared to three on domperidone, and eight additional women who continued metoclopramide on a follow-up prescription also reported problems. Domperidone doesn’t cross into the brain as readily, which is why it causes fewer mood-related and neurological side effects. It’s widely available in Canada, Australia, and Europe but is not FDA-approved in the United States, which is why American mothers are more commonly prescribed Reglan.
Making the Most of a Short Course
Think of Reglan as a window of opportunity rather than a long-term solution. During the days you’re on it, maximize milk removal: pump after nursing sessions, add a middle-of-the-night pump if you can manage it, and ensure proper flange fit so you’re draining the breast effectively. The more milk you remove while prolactin is artificially elevated, the more your body calibrates to a higher production level that can persist after you stop the medication.
Skin-to-skin contact, adequate hydration, and caloric intake all support the process. Some mothers also use herbal options like fenugreek alongside Reglan, though the evidence for herbal galactagogues is much weaker. The single most effective thing you can do during treatment is remove milk frequently and completely. When it’s time to taper, your prescriber will typically reduce the dose over 5 to 7 days to give your body time to maintain supply on its own.