The main thing to bear in mind with Depo is that once you get your shot, you're stuck with it until the shot wears off.
So, personally, since side effects are similar for ALL hormonal methods, I'd suggest trying a more reversible one first to find out how your body reacts to hormonal birth control.
If you feel forgetfulness is an issue with you, you could consider the patch, for instance.
But ultimately, the person to talk to about this is your GYN.
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