8. After addiction, withdrawal from the use of caffeine can cause mood swings and irritability, similar to the symptoms of withdrawing from a narcotic or alcohol. 9. Consuming as little as 200mg of caffeine every day can lead to addiction and altered chemistry in the brain.
Progestin is a form of progesterone, a hormone that plays a role in the menstrual cycle and pregnancy. Progestin is used in combination with another hormone called estrogen in combined hormonal birth control pills, the vaginal ring, and the skin patch.
So, they manufactured the pill to mimic a typical 28-day cycle. This is why many birth control packets contain three weeks worth of hormonal pills and one week of placebos or sugar pills. Withdrawal from the hormones on the fourth week triggers bleeding that's similar to menstruation.