Cortisone is a powerful anti-inflammatory medication. A cortisone shot starts to work very quickly once injected, and most people find that relief begins within 48 to 72 hours.The duration is only 30-36 hours and is excreted in the urine or stool.
Take care and regards.
i had a corticosteriod shot for a cyst how long it stays in your system
Cortisone injections are not the same form of illegal steroids used in the sports arena. It sounds as if this is your concern. If an athlete has found it necessary to use cortisone for health reasons, he should supply a note from the doctor before drug testing. I wouldn't know when it can be expected to fully clear the blood, but I can tell you that the benefits of a cortisone injection for me can last, unpredictably, a few weeks.