All oral steroids are designed at the molecular level in such a way as to not be destroyed totally in the gut, and to be absorbed into the blood. The blood passes through the cleaning cycle through the liver, which is the main body filter, where a fair share of the drug is deactivated. This is the main cause of death of liver cells in impact with oral steroids. Of course, steroid pills are very easy to use. It's often used by people who are afraid of injections. Another advantage and disadvantage at the same time is that oral steroid remain active in the body not for very long and are rapidly destroyed in the liver. The lifetime of steroid pills is up to 24 hours.
For this reason, this type of drugs are administered in equal dosages during the day to maintain a high level of hormones in the blood. Oral steroids are very convenient for athletes who are in competition and are subject to doping control. I recall that oral steroids are acting and removed fast from the body. So depending on your body after taking steroid pills, in 5-10 days, no test will detect you have any metabolites or hormones in urine or blood. Also in the conclusion of the story about this group of steroids, I would like to note that typically injectable and oral preparations of a steroid at the same dosage differ in strength and duration of action. From the words of many athletes, oral form of steroids is weaker than the injectable steroid. And that is because the biochemistry of drugs is different.