You've probably heard of "orals" or 17-alpha alkylated (17aa) steroids. Examples are winstrol, anavar/oxandrolone, dianabol, halotestin, etc. Examples that are NOT 17aa steroids are test propionate, NPP, test enanthate, equipoise, etc.

These are generally known to be harsh to the liver. Generally speaking, guys are encouraged to NOT run all-oral cycles because of this - primarily because of the dosages men would require. They do use them in conjunction with other injectibles, but keeping the orals to short runs like 4-6 weeks and including liver support (milk thistle, or products like Tyler's Liver Support, LIV 52, etc). Women, on the other hand, very commonly use anavar or winstrol, because they are short esters and will clear quickly, are relatively mild in terms of sides, and do not require injection (i.e. they appear to be just a pill you pop and not a real steroid that requires needles. Less scary. Less "hardcore".) Also at low doses like 10 mg ED, they can be run for longer periods of time, producing nice, maintainable results.

Here are some references about 17aa steroids:
Note: as w/ all internet sources, please be intelligent about reading information and keep it context and relative to other things you read.