What is rye grass pollen extract? Rye grass pollen extract comes from the pollen of rye grass (Secale cereale). Rye grass pollen extract may affect the male hormone testosterone, relax the muscles of the tube through which urine flows (urethra), and improve how well the bladder can force urine out.ye grass pollen extract may affect the male hormone testosterone, relax the muscles of the tube through which urine flows (urethra), and improve how well the bladder can force urine out.