True statements regarding DMPA includes all the following except
3% failure rate
Useful in treatment of menorrhagia
Can be given in women with seizures
Protects against ovarian cancer
Risk of endometrial cancer is substantially reduced by past use of DMPA.
Noncontraceptive benefits of DMPA:

Anemia, PID, Ectopic pregnancy, and Endometrial cancer are reported.
DMPA benefits women with sickle cell disease.