The "experimental steroid" John is using is seen towards the end and is stored in crates labeled methylphenidate, which is not itself an illegal drug. Available in pill and capsule form, it is used to treat ADD and ADHD and is the active ingredient in drugs such as Ritaline, Attentin and Concerta. However, a producer and dealer of illegal steroids obviously wouldn't want to announce his products or its chemical names to anyone catching a glance, which explains why a common drug name is used on its crates.
When Slade has his flashback it appears his left eye is covered by a bandage. His right eye was taken. In the next shot the correct eye is covered. However there is a mirror in the background, and looking closely its clear that part of this scene is of his reflection, explaining it looks like the wrong eye was bandaged.