Article PubMed
Fertility and sterility  (2006)

Progesterone at the picomolar range is a chemoattractant for mammalian spermatozoa.

Teves, María Eugenia; Barbano, Flavia; Guidobaldi, Héctor Alejandro; Sanchez, Raúl; Miska, Werner; Giojalas, Laura Cecilia