<prompt> What is the effect of Progesterone only pills?Completely suppresses ovulationThin lining of uterusThick cervical mucusAll of the above  <response>: Progestogen-only pills Progestin-only Pills POP Morning after pills - Contraceptive pills Contain only synthetic progestins doesnt contain estrogen. Mechanism: Mucus thickening in neck of womb: Penetration of sperm to reach egg and womb becomes difficult. Prevents ovulation: Lining of the uterus becomes thin Feilized egg implantation is prevented Advantages: Doesnt interfere with breastfeeding Also helps in premenstrual symptoms and painful periods REF : SHAW GYNECOLOGY 