Yes, I think that birth control should be administered before the age of 18 in some cases. It should at least be an option for teenagers and their parents. The fact is, if a teenager is going to have sex, they're going to have sex. At least giving them access to birth control will help protect them from STDs and pregnancy.
The various forms of prescribed birth control are FDA approved pharmaceutics that have medical uses other than just preventing pregnancy. The decision to prescribe any approved medication should be one made by a medical professional in consultation with their patient. The government has no compelling interest in blocking access to FDA approved drug. So birth control should be available without an age restriction.
I think that there is plenty to be gained by giving birth control to people who are under the age of 18. If we want to take the issue of teen pregnancy seriously, then the best way to go about doing so is to spread birth control as wide as possible.
In addition to preventing pregnancy, oral contraception provides many benefits. First of all, it helps to lessen the strain of a girl's menstrual cycle. There is less blood flow and less cramping. This makes it more possible for her to go about her daily activities. Oral contraception also lessens the mental mood swings that often happen the week before menstruation. It also helps fight against acne.