You might be wondering how cough syrup can relate to fertility in any form or fashion. Actually, evidence suggests it can help. Guaifenesin (GWY-fen-uh-sin), the principal active ingredient in some leading cough syrups, is a mucolytic agent. This means it liquefies cervical fluid in the female body. This can be important for women who have thick or scanty cervical fluid, since it allows the sperm an easier and quicker path into the uterus and beyond. The particular syrup recommended is one with no initials after the name like DM (D-M) or CF (C-F). Some cough medicines contain antihistamines that dry up all your fluids, so make sure to read the label. Take as directed for about five days before ovulation. Medical evidence to support this is not conclusive, but it's relatively safe and inexpensive.