How to use
Warmth, right where you need it.
Open, wait 2–3 minutes as it warms, stick to underwear or low belly over fabric. Wear up to 8 hours. Don't sleep on it or apply to broken skin.
Period comfort · Thin & discreet
FlowWarm Period Heat Patches
FlowWarm is an air-activated heat patch for period cramps — thin enough to wear under leggings at school or work. It warms up in minutes and delivers steady, soothing heat right where cramps hit for up to 8 hours. No cords, no microwave, no one knows it's there.
Wear over fabric. Do not sleep on the patch or use on broken or heat-sensitive skin. Remove if it feels too warm.
- Up to 8 hours of steady warmth
- Ultra-thin and silent under clothes
- Adheres to underwear or lower belly area
- Heat is one of the best-evidenced comforts for cramps
- 8 patches per pack — $1.50 per day saved
$11.99 · 8 patches
60-day guaranteeSecure Stripe checkoutFree shipping $29+
Free US shipping over $29 · 60-day guarantee
What's inside
Simple, air-activated warmth.
Iron powder, activated charcoal and salt — the same safe air-activated warming used in hand warmers, sized and shaped for cramps.
Questions, answered
FlowWarm FAQ
How hot does it get?
Comfortably warm (around 50°C/122°F peak through fabric), designed for hours of wear — not burning hot.
Can I wear it to school?
That's the whole point: thin, silent, invisible.
Skin-safe?
Wear over fabric; remove if too warm; not for sensitive or broken skin.
Reusable?
Single-use; each lasts up to 8 hours.
From the Learn hub
First period kit checklist
Plain-language guidance, safety context and practical next steps.
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