"You can imagine attaching the peptides to spermicidal sponges, or to vaginal rings impregnated with hormones," Dean says.

These spermicidal pessaries could be found at the Mother’s Clinic in London starting in the 1920s.

Behr said he was surprised a few years back when he learned Astroglide, "a lubricant marketed to fertility practices, had some spermicidal properties."