A steroid shot generally starts working immediately in terms of reducing inflammation, but pain relief typically takes a few days to a few weeks to become noticeable. Most people see improvement within 3 to 10 days, though it can take up to a week or sometimes longer depending on the severity and chronic nature of the condition. The injection works by decreasing inflammation, which then leads to pain relief as the inflammation subsides. In some cases, the relief can last for several weeks to months. Immediate relief is sometimes experienced if the shot includes a local anesthetic or if fluid is drained from a swollen joint at the same time. If no improvement is felt after about 10 days, it is advised to consult a healthcare provider.