2mg became standard from the egrifta HIV research, so it's the go-to now. The 5 on, 2 off schedule works out great for those 10mg bottles in that dosage range. Some folks prefer 1mg instead. Getting your IGF-1 checked beforehand and after helps track how well you're doing on it.
Sharing vials with someone who got the same sting/burn effect from the same batch and timing, yet the other person felt nothing. Both injected simultaneously, other person on higher dose. Ice for 30 min helped. Three times in a row it happened, then stopped. No bruising but some sensitivity earlier.