NPH

One of the more common forms of insulin is "NPH." But how many of us know what NPH even stands for? We write for it all the time, but I doubt more than a handful of residents actually know why it's called NPH. "Neutral Protamine Hagedorn" is named after Hans Christian Hagedorn who obtained the rights to insulin. He then discovered that the effect of insulin could be prolonged by adding protamine (the same protamine used to reverse heparin, which incidentally is from trout semen). However, this only worked if the insulin formulation was pH 7. Hence, Neutral Protamine Hagedorn.

Image of insulin is in the public domain, from Wikipedia.