Contraceptive patch: This is a small, thin trans-dermal patch made of plastic which when placed on the skin releases estrogen and progestin.
Female Birth Control Options - Family Planning
These hormones stop ovulation, hence the egg does not leave the ovaries for fertilization. It also tends to make the cervical mucus thicker, thus inhibiting sperm motility.
It should be placed on the upper arms, buttocks, thighs, or abdomen. It is usually put on the first day of periods and kept in place for a week.
Exactly on the seventh day (second week), the patch is replaced by another, and again by a new patch on the third week. The fourth week is the patch-free week, and this process is repeated again.
Effectiveness %: 90-98%
Possible side effects: Weight gain, dizziness, irregular periods, depression, mood swings.