If you're talking about stealth injectables from AS it should be smooth, especially if you live in the U.S. But the main reason I wanted to post is to warn you to do extensive research before even touching one of those sachets! It is a very careful, STERILE, process transfering those sachets into sterile vials. Then, if its supertest 450 you bought there's more to be concerned with.
Some say it's got histamines in it, hence using benadryl day of and after injection, a high benzyl alcohol content, hence cutting it with sterile oil or mixing with another compound. My first injection was a cc in the glute-swelled so bad within 5 days that I went to the E.R. to get on antibiotics in case it turned into an infection which the doc said it did.
I just think that it was an allergic reaction or something but it's almost gone now. Next, did .5cc in the quad and was limpin for the next 4 days but not nearly as bad as the glute. Now I just opt to do .3cc shots everyday and there is barely any pain at all and I still get a little over 900mgs a week. Stealth is a VERY STRONG, awesome product. You will see great gains as long as you can get past the pain issue.Sorry to ramble on but I just don't want to see you go through what I did!