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glossary

What is letdown?

Pumping glossary; plain language, no fluff · Updated July 2026

Quick answer: Letdown (milk ejection reflex) is the hormone-triggered release that pushes milk from the glands into the ducts: oxytocin contracts tiny muscles and milk begins to flow, often felt as tingling or pressure, sometimes felt not at all.

In practice

Pumping letdowns respond to cues: warmth, massage, baby photos or videos, and relaxation, which is why stressed sessions underperform. Most sessions contain 2 or 3 letdown waves; pumps' stimulation modes exist to trigger them. A weak letdown at the pump with a strong one while nursing is common and trainable.

Milk First pump timer with two-tap logging

In Milk First

Log any session in two taps, backdate the ones you forgot, and let the 7-day average chart answer supply questions with real numbers. Every pump files its milk into the stash automatically.

Milk First speaks this whole language for you: seshes logged in two taps, every bag on its correct clock.

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