Delatestryl contains the hormone testosterone in a special oil formulation that is injected into a muscle. Testosterone is slowly absorbed from the oil into the body, allowing for injections just once every two to four weeks in most cases. It works by increasing testosterone to a normal level.
Delatestryl is used as an injection rather than taken by mouth because it would have little effect on testosterone levels if taken orally. When medications are taken by mouth, they must first pass through the liver before they reach the bloodstream. The liver metabolizes testosterone extensively before it has a chance to reach the bloodstream, and adequate blood levels of the medication usually cannot be achieved. However, when testosterone is injected into a muscle, it bypasses the liver, allowing significant amounts of the hormone to reach the bloodstream.
Delatestryl is sometimes used to help start puberty in adolescent boys who would otherwise not go through puberty without the help of additional hormone replacement. There are no widely accepted uses for Delatestryl in younger children. Children or teens treated with this drug must be very carefully monitored for undesired bone changes by a specialist experienced in such matters.
On occasion, a healthcare provider may recommend this product for something other than treating low testosterone in men. This is known as an off-label use. Off-label uses for Delatestryl include treating the following conditions:
- Low testosterone in women (even though testosterone is thought of as a "male" hormone, women also produce a little)
- Types of cancer in women other than breast cancer
- Hormone therapy in transgender individuals as part of a "sex change" process
- Slightly low, but still considered normal, testosterone levels in men.
Androgens, including Delatestryl, are sometimes used to enhance athletic performance. However, this use is considered unethical, both from a medical standpoint and from an athletics point of view.