Final answer:
The injectable contraceptive with high doses of progestin is Depo-Provera, which is administered every 3 months and prevents ovulation.
Step-by-step explanation:
The injectable contraceptive that contains high doses of progestin is Depo-Provera. This method involves receiving injections or shots of the hormone progestin every 3 months, either in the buttocks or arm. A newer type can be injected under the skin. The birth control shot works primarily by preventing the ovaries from releasing eggs and also causes changes in the cervix that inhibit sperm from joining with the egg.