Human Growth Hormone is an injectable hormone that can be administered subcutaneously or intramuscularly. When injected subcutaneously, HGH carries a bioavailability of approximately seventy-five percent. When injected intramuscularly, HGH carries a bioavailability of approximately sixty-three percent. The mode of administration will also affect the half-life of the Somatropin hormone. When injected subcutaneously, it will carry a half-life of approximately hours. When injected intramuscularly, it will carry a half-life of approximately hours. While this is a rather short half-life regardless of the mode of administration, keep in mind the total effects far outlast these numbers due to the pronounced and significant increases in IGF-1 production that stretch far past the twenty-four hour mark.
Steroid isolation , depending on context, is the isolation of chemical matter required for chemical structure elucidation, derivitzation or degradation chemistry, biological testing, and other research needs (generally milligrams to grams, but often more  or the isolation of "analytical quantities" of the substance of interest (where the focus is on identifying and quantifying the substance (for example, in biological tissue or fluid). The amount isolated depends on the analytical method, but is generally less than one microgram.  [ page needed ] The methods of isolation to achieve the two scales of product are distinct, but include extraction , precipitation, adsorption , chromatography , and crystallization . In both cases, the isolated substance is purified to chemical homogeneity; combined separation and analytical methods, such as LC-MS , are chosen to be "orthogonal"—achieving their separations based on distinct modes of interaction between substance and isolating matrix—to detect a single species in the pure sample. Structure determination refers to the methods to determine the chemical structure of an isolated pure steroid, using an evolving array of chemical and physical methods which have included NMR and small-molecule crystallography .  :10–19 Methods of analysis overlap both of the above areas, emphasizing analytical methods to determining if a steroid is present in a mixture and determining its quantity.