Injecting - 1st timer nervous about possible miss

[RHINESTONECOWBOY]

So swims friend tried her first shot today and insisted on the large bulging vein in her foot so she could be steady with two hands. After registering, swim's friend slowly injected a very small amount of liquid in, didn't feel a burn, attempted to flag again, and simply got nervous and pulled out. Right afterward, the site swelled (about a 50 cent piece size) up about a quarter inch and was blotchy red/white, and itches just a little bit. a slight histamine feeling, she says. The swelling has subsided after about 30 minutes, but it's still a little red and swollen, and is painful to the touch. Swim's friend is worried because this was her first experience. She said she felt a minor opiate rush after injection, but only a small amount of liquid was pushed in... so very minor.

Swim knows there's lots of these threads, and after attempting to console his friend with searching and reading, she still insisted on asking the forum directly about the issue. Any opinions? Thanks ahead of time.