Endogenous substances and processes are those that originate from within a living system such as an
organism,
tissue, or
cell.
In contrast,
exogenous substances and processes are those that originate from outside of an organism.
For example,
estradiol is an endogenous
estrogen hormone produced within the body, whereas
ethinylestradiol is an exogenous synthetic estrogen, commonly used in
birth control pills Oral contraceptives, abbreviated OCPs, also known as birth control pills, are medications taken by mouth for the purpose of birth control.
Female
Two types of female oral contraceptive pill, taken once per day, are widely available:
* The combin ...
.
References
External links
*{{Wiktionary-inline, endogeny
Biology