A pre-filled pen instead of a vial and syringe: 36 IU of somatropin, which is 12 mg of hormone, in a cartridge device from the Pfizer and Eli Lilly pen range.
Somatropin is recombinant human growth hormone — a 191-amino-acid protein produced in engineered cells, identical in sequence to what the pituitary secretes. Its medical use is in growth hormone deficiency. The pen is the defining feature of this listing: the amount delivered is dialled in fractions of a unit rather than measured in a syringe, nothing is mixed by hand, and the cartridge stays sealed inside the device between injections.
