It is safe enough though corticosteroids are catabolic and you must not take them longer than prescribed using either a high dose for about 5 days or if you go longer you must do a taper, ask your doc. I have taken several courses over the past 2 years due to bad inflammation and the stuff is amazing for me though I ended up getting Depo Medrol injection right into the shoulder finally. Depo Medrol is also available in an oral and it is essentially the same as Prednisone but much stronger on a milligram per milligram basis.