“Our findings suggest that the evolution of multicellular animals began earlier than has been thought,” said Gordon Love, an assistant professor of Earth sciences, who led the research group. Love began working on the project while he was a postdoctoral researcher at MIT. “Moreover, sponges live on the seafloor, growing initially in shallow waters and spreading, over time, into deeper waters, implying the existence of oceanic environments which contained dissolved oxygen near the shallow seafloor around 635 million years ago.”
Transdermal patches (adhesive patches placed on the skin) may also be used to deliver a steady dose through the skin and into the bloodstream. Testosterone-containing creams and gels that are applied daily to the skin are also available, but absorption is inefficient (roughly 10%, varying between individuals) and these treatments tend to be more expensive. Individuals who are especially physically active and/or bathe often may not be good candidates, since the medication can be washed off and may take up to six hours to be fully absorbed. There is also the risk that an intimate partner or child may come in contact with the application site and inadvertently dose himself or herself; children and women are highly sensitive to testosterone and can suffer unintended masculinization and health effects, even from small doses. Injection is the most common method used by individuals administering AAS for non-medical purposes. 
To improve the AAS research, biochemists have created an objective to alter the molecules to be "more anabolic and less androgenic" than testosterone, in which makes it possible to take orally, and have a reduce effect on the HPG axis (Stephen Kishner, page 3). According to an article called, Anabolic Steroids Use and Abuse, by Stephen Kishner, "AASs is developed from 3 compounds: testosterone, dihydrotestosterone, and 19-nortestosterone", (Kishner, page 3). (Testosterone and 19-nortestosterone is a very similar compound, very much alike except 19-nortestpsterone doesn't include the 19th carbon).