Anabolic processes tend toward "building up" organs and tissues . These processes produce growth and differentiation of cells and increase in body size, a process that involves synthesis of complex molecules . Examples of anabolic processes include the growth and mineralization of bone and increases in muscle mass. Endocrinologists have traditionally classified hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The classic anabolic hormones are the anabolic steroids , which stimulate protein synthesis, muscle growth, and insulin .  The balance between anabolism and catabolism is also regulated by circadian rhythms , with processes such as glucose metabolism fluctuating to match an animal's normal periods of activity throughout the day. 
The legal status of anabolic steroids varies from country to country. In the ., anabolic steroids are listed as Schedule III controlled substances under the Controlled Substances Act , which makes the possession of such substances without a prescription a federal crime punishable by up to seven years in prison.  In Canada, anabolic steroids and their derivatives are part of the Controlled drugs and substances act and are Schedule IV substances, meaning that it is illegal to obtain or sell them without a prescription. However, possession is not punishable, a consequence reserved for schedule I, II or III substances. Those guilty of buying or selling anabolic steroids in Canada can be imprisoned for up to 18 months. Importing or exporting anabolic steroids also carry similar penalties.  Anabolic steroids are also illegal without prescription in Australia,  Argentina, Brazil, and Portugal,  and are listed as Schedule 4 Controlled Drugs in the United Kingdom.