The dry HGH "puck" should be under vacuum. As soon as stick a needle with BW into the vial the BW is "sucked" in by the vacuum. It's a chore to try and hold the plunger back so it doesn't get sucked in. I've been letting the vacuum suck in the BW for years and it seems to be working ok. I could probably optimize the whole process by letting the BW trickle in drop by drop but I ain't got all day.![]()