As with any horomonal birth control, they're normally effective after a week. However, since this is slightly different, it might be 24 hours. Why didn't your doctor tell you?

She is the one that told me 4 weeks. My friends so that's way off. I just wanted to be double double sure.....

.you should always go with what your doctor tells you. .they didn't go to medical school for nothing.

Depo is typically effective after 24 hours, unless something changed rather recently. I have no idea why your doctor told you four weeks. You could call and ask, see if you misunderstood, or if there is some reason she said that.

According to the following sources:

This one says 24 hours:
http://www.fwhc.org/birth-control/bcdepo.h tm

This one says instant protection:
http://www.depoprovera.com/howitworks.asp

This one says 2 weeks unless the injections is
a) in the first five days of your menstrual period
b) within five days of an abortion
c) within five days of giving birth
http://www.womenshealthmatters.ca/centres/ sex/birthcontrol/depo.html

This one says 24 hours:
http://www.sexualityandu.ca/adults/contrac eption-2-3.aspx

I don't know from personal experience, sorry. Best to phone your doctor. Please read about the side effects too.

I've been on Depo because of Endemetrosis for over 6 years. Depo is very effective, but then again, I had my tubes tied when I was 25 (childfree, didn't want any), but anyway, it took almost a couple of years before bleeding completely stop. I've had no problems with it, but now have been advised that I need to do something else because I've been on it soooooo long. Anyway, good luck!

Ive been on depo for almost 3 months.. and I'm about to go get my second shot at the end of this month...should I stop having sex like a week before my shot? or is it still effective up until my next shot??

You should be protected right up until the next shot. If you're unsure, call your doctor.

Since you are going back for your 2nd depo shot, you don't have to stop having sex. Once you get the depo shot, it's effective and stays in your system. If I stopped depo today, it would probably take a while for it to get out of my system.

okkk thank you for the response, I probably should have gotten that cleared up with my doctor.