From Mooncup website:
The Mooncup will hold 30ml of fluid, which is roughly one third of the average total produced each period.
also from website:
It holds 30mls of menstrual blood, approximately 3 times more than a tampon or sanitary towel.
This means you will need to attend to your mooncup less often than when wearing conventional sanitary protection.
Textbooks describe 80mls+ produced over the whole cycle as a heavy period.
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