Genotropin GoQuick Pen is manufactured by Pfizer and is a FDA approved Human Growth Hormone. The nice thing about the pen is that it comes unreeconstituted. The Genotropin GoQuick pen is that the pen has two separate compartments; the first is the HGH solvent, and the second is the bacteriostatic water. When you open the pen, you turn it into position which combines the two compartments of HGH and bacteriostatic water to make solution. The pen's concept makes it great for traveling and shipping.