Do steroid injections for trigger finger take a couple days or weeks to be effective, or should improvement be instantaneous?

steroid does not provide instant relief...it usually takes a day or so to START working. Some doc mixes a bit of lidocaine (AKA novacaine) which can provide brief but more or less instant relief. In some cases, steroid injection may not work at all---a different steroid may work etc...I hope you are getting some relief. Consult doc. good luck

Some patients report that their finger feels great the morning after the trigger finger injection. Others may not experience improvement for several weeks. But on average, it takes three to seven days for a cortisone injection to take effect. 50% of patients get better after one injection, 25% after the second and 25% do not improve from injection at all.