Testosterone can be administered parenterally , but it has more irregular prolonged absorption time and greater activity in muscle in enanthate , undecanoate , or cypionate ester form. These derivatives are hydrolyzed to release free testosterone at the site of injection; absorption rate (and thus injection schedule) varies among different esters, but medical injections are normally done anywhere between semi-weekly to once every 12 weeks. A more frequent schedule may be desirable in order to maintain a more constant level of hormone in the system.  Injectable steroids are typically administered into the muscle, not into the vein, to avoid sudden changes in the amount of the drug in the bloodstream. In addition, because estered testosterone is dissolved in oil, intravenous injection has the potential to cause a dangerous embolism (clot) in the bloodstream.
High dosages of oral corticosteroids taken daily for prolonged periods of time can have serious systemic side effects including bone loss ( osteoporosis), increased risk of infections and diabetes and cataracts, thinning of skin, stretch marks, increased facial/body hair growth, acne, fluid retention, weight gain with redistribution of fat (fat deposits on back and face, thinning of limbs), muscle weakness, decreased resistance to infections, stomach ulcers, mood swings, insomnia, suppression of the body's own production of cortisol, etc.
This is a rare complication that may occur if a small hole is made in the fibrous sac and does not close up after the needle puncture. These small holes are only made in less than 1% of epidural injections and usually heal on their own. The spinal fluid inside can leak out, and when severe, the brain loses the cushioning effect of the fluid, which causes a severe headache when you sit or stand. These types of headaches occur typically about 2-3 days after the procedure and are positional - they come on when you sit or stand and go away when you lie down. If you do develop a spinal headache, it is OK to treat yourself. As long as you do not feel ill and have no fever and the headache goes away when you lay down, you may treat yourself with 24 hours of bed rest with bathroom privileges while drinking plenty of fluids. This almost always works. If it does not, contact the radiologist who performed the procedure or your referring physician. A procedure (called an epidural blood patch) can be performed in the hospital that has a very high success rate in treating spinal headaches.