Does steroids affect the healing process?

Slows it down: One of the most integral parts of healing is inflammation. This means that the body ramps up its activities and brings fresh blood and healing factors to the injured area and opens up the veins to drain the "bad" stuff away. It means things get red, hot, swollen, and tender. Steroids (and motrin/advil) are antiinflammation which means they slow down the inflammatory process and thus healing.