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(Mira Miller/ Very Well Health) — No one really tested the absorbency of menstrual products with real period blood before—not even the manufacturers themselves.
Many consumers were shocked by a recent study published in the journal BMJ Sexual and Reproductive Health, which found that most period products had either a much lower or higher capacity for blood than what was advertised. Researchers tested tampons, sanitary pads, menstrual cups and discs, and period underwear.