Just a few suggestions to minimize bruising, and forgive me if you already know all this:
1. When using very
thin needles, try injecting more slowly
to avoid the bruising that's more likely because of the increased force caused by the narrow gauge needle. (Your tissues will have a better chance to accomodate the injected fluid with less trauma if it isn't blasted in there like a tiny fire hose
2. But before injecting, always, always
be sure the needle is perfectly clean(obviously) and dry
, with absolutely no medication or alcohol on it.
3. While you're at it, make sure the alcohol on your skin has totally dried before injecting too. It probably won't help with the bruising, but does help prevent scar tissue at injection sites. Alcohol isn't good for internal tissues.