The table below is based on documents produced by the Faculty for Sexual and Reproductive Health (FSRH).

Standard contraceptives:

Contraceptive Mode of action
Combined oral contraceptive pill Inhibits ovulation
Progestogen-only pill (excluding desogestrel) Thickens cervical mucus
Desogestrel-only pill Primary: Inhibits ovulation
Also: thickens cervical mucus
Injectable contraceptive (medroxyprogesterone acetate) Primary: Inhibits ovulation
Also: thickens cervical mucus
Implantable contraceptive (etonogestrel) Primary: Inhibits ovulation
Also: thickens cervical mucus
Intrauterine contraceptive device Decreases sperm motility and survival
Intrauterine system (levonorgestrel) Primary: Prevents endometrial proliferation
Also: Thickens cervical mucus

Methods of emergency contraception:

Contraceptive Mode of action
Levonorgestrel Inhibits ovulation
Ulipristal Inhibits ovulation
Intrauterine contraceptive device Primary: Toxic to sperm and ovum
Also: Inhibits implantation

Contraceptives - time until effective (if not first day period):

Injectable Contraceptives

COCs

POPs

Post-partum contraception

Missed Pills

Emergency Contraception

IUD & IUS

Nexplanon (New version of implanon)

Key points