Sore at injection area..

I already talked to my vet, Nermal is having some tenderness around the area where he got his hormone injection. They said hot pack it for a little bit and keep an eye on him. He went pee so thats good. But they're all pretty sleepy today and not moving much, Im guessing its mostly the stress from going to the vet yesterday. Anyway, Nermal grumbles when I touch the area and his skin twitches a bit and his tail is going. Has anyone else had a cat have a slight reaction to any shots? How long does it usually last? Im trying not to freak out but Im a worrier.

My Drama Queen Maggie, always acts like her whole leg is going to fall off after they give her any kind of shot. She will flop down on the floor and extend her leg and if it touches anything draw it back and scream like you choped it off. I know this about her, but she also tends to have allergic reactions to certain shots. So after talking with the vet she gets pretreated with bendaryl before hand. I have noticed that my other cats legs tend to be tender at the injection site, but I guess since it's intermuscular I'm not that supprised that it is painful. I've had a very tender arm from shots.

Out of curiousity what is the hormone shot for?

Its a female hormone that is supposed to hopefully stop their spraying. It looked like the vet just lifted some skin around the hip area and gave the shot there so it doesnt seem like it should be too sore. His whole side twitches when I touch it and he grumbles a bit so I know its bothering him. None of the others have a problem, thank goodness. I gave him a little canned food and he ate it which made me feel better. Right now he's sleeping in the sun so Im hoping the heat will make it feel better. Im so worried/stressed

Don't be worried!

I just went thru the exact same thing with my 16 week old kitten 3 days ago!

He got 2 shots (1 for rabbies) and the whole night he was crying out in pain if i tried to touch him. He was acting like i am trying to cut his head off lol

He also slept for 2 days in a row and wouldnt let anyone touch him. It scared me to death because he was just dragging his left leg behind him like it was broken off

anyway, he is back to normal this morning and running around lke a little horse!