Oxymetholone is without a doubt the strongest and most visibly active steroid to date. Not only does it act very rapidly, it causes a virtual explosion of mass. Gains of up to 10 pounds in 2 weeks are not uncommon. This is largely due to a moderate to low androgenic effect combined with a high anabolic activity also mediated by non-AR mechanisms (mechanisms other than simply binding the androgen receptor). You can imagine that the gains made on oxymetholone aren't the leanest. You would note a drastic smoothing out of the muscle due to estrogen-related fat (lipolysis) and water retention. This lipolysis has been shown to be rather drastic. One study1 on long-term hemodialysis patients showed beyond a doubt the role that oxymetholone can play in causing hyperlipedemia. The fat deposition rate, post-hepatic (after processing by the liver), increased drastically in the oxymetholone group while numbers remained stable in the control group.
Like most other anabolic steroids Anadrol also has a big list of side effects behind it including things such as water retention, headaches, and hormone suppression. Similar to a lot of the other oral steroids, Anadrol is also 17-Alpha-Alkylated in order to allow it to survive the first pass through the liver, but this also makes it very toxic to said organ; in fact it has the worst reputation out of all of the steroids with regards to hepatotoxicity. It is interesting to note that although one of the benefits of Anadrol is increased appetite, people tend to experience the opposite when taking high dosages.