In terms of science, how does birth control work?

Question

I know that you're taking hormones, but how exactly does it work? No mechanisms or anything like that, I just want to know what hormones affect what in your body (like does testosterone increase? and estrogen? how does this affect your body?)

I haven't been able to find answer to this question on yahoo answers! Wiki has it, but I'd feel better if i can hear it from someone who knows what they're talking about. 10 points to the first good answer ^^ (i'm sick of hearing that i ingest estrogen/progestin... yes i know... now tell me how does this affect other hormones...)

Answer 1

the birth control pill fools your body into thinking that it's already pregnant, so no egg is released each month.  that's why you have to take the "sugar pills" for 5 days so you can release the blood and other nutrients and have a period.

I'm not sure why you need someone to reiterate what is already in wiki, it even has references

"Combined oral contraceptive pills were developed to prevent ovulation by suppressing the release of gonadotropins. Combined hormonal contraceptives, including COCPs, inhibit follicular development and prevent ovulation as their primary mechanism of action.[2][20][58][59][60]

Progestagen negative feedback decreases the pulse frequency of gonadotropin-releasing hormone (GnRH) release by the hypothalamus, which decreases the release of follicle-stimulating hormone (FSH) and greatly decreases the release of luteinizing hormone (LH) by the anterior pituitary. Decreased levels of FSH inhibit follicular development, preventing an increase in estradiol levels. Progestagen negative feedback and the lack of estrogen positive feedback on LH release prevent a mid-cycle LH surge. Inhibition of follicular development and the absence of a LH surge prevent ovulation.[2][20][58]

Estrogen was originally included in oral contraceptives for better cycle control (to stabilize the endometrium and thereby reduce the incidence of breakthrough bleeding), but was also found to inhibit follicular development and help prevent ovulation. Estrogen negative feedback on the anterior pituitary greatly decreases the release of FSH, which inhibits follicular development and helps prevent ovulation.[2][20][58]

A secondary mechanism of action of all progestagen-containing contraceptives is inhibition of sperm penetration through the cervix into the upper genital tract (uterus and fallopian tubes) by decreasing the amount of and increasing the viscosity of the cervical mucus.[60]"

Answer 2

Here's a site to answer your question:

http://kidshealth.org/teen/sexual_health...

Answer 3

actually when you take synthetic hormones  estrogen etc. through your birth control your body starts making less of that hormone naturally(the same as taking steroids and t******e shrinkage). so your body actually goes more into a state of slight menopause because you are now making less hormone