6 weeks for cortisol shot to have max effect? Is that right?

I got a cortisol shot two weeks ago and so far I haven’t felt much if any improvement. If anything, my whole hand just feels a little weaker. Like, if I relax it, it naturally wants to fold over at a right angle to my wrist, like it’s a sock puppet.

My hand surgeon said to give it six weeks for maximum effect and then see him again. Has anyone else heard about a six week period?