Vitamin C helps elevate progesterone levels to help thicken the uterus and lengthen luteal phase (the stage of menstruation when pregnancy is possible). L-Arginine and Grape Seed Extract improve blood flow to the uterus and ovaries to enhance cervical mucus and egg quality. N-Acetyl L-Cysteine (NAC) has been shown to support pregnancy by increasing number of follicles.