Steroid crib sheet: a very brief look at steroid nomenclature

Source: International Union of Pure and Applied Chemistry (IUPAC). Nomenclature of Steroids (for hard-core nomenclature junkies only.)

Structure and numbering of the steroid nucleus

5α-Gonane

5β-Gonane

5α-Estrane

Other names: 13β-Methyl-5α-gonane and 19-Nor-5α-androstane.

5β-Estrane

Other names: 13β-Methyl-5β-gonane and 19-Nor-5β-androstane.

5α-Androstane

Other names: 10β,13β-Dimethyl-5α-gonane and 10-Methyl-5α-estrane.

5β-Androstane

Other names: 10β,13β-Dimethyl-5β-gonane and 10-Methyl-5β-estrane.

5α-Pregnane

Another name: 17β-Ethyl-5α-androstane.

5β-Pregnane

Another name: 17β-Ethyl-5β-androstane.

Testosterone (17β-Hydroxyandrost-4-en-3-one)

A familiar steroid, named as a substituted, unsaturated androstane ketone. As with some other steroids, the double bond at the 5 position removes a stereogenic centre.