Deca-Durabolin, also known by its generic name nandrolone decanoate, is an anabolic steroid used in medical settings to treat certain conditions such as anemia, osteoporosis, and muscle-wasting diseases. It is also used by bodybuilders and athletes for its potential performance-enhancing effects. 
The benefits of Deca-Durabolin 100mg lie in its ability to promote muscle growth, increase red blood cell production, and improve bone density. This can result in enhanced muscle mass, increased strength, and potential improvements in athletic performance. In medical contexts, it can help patients with specific health conditions regain muscle mass and improve their overall well-being.
However, it's important to note that the use of Deca-Durabolin for non-medical purposes is often associated with a range of serious side effects and health risks, including hormonal imbalances, cardiovascular issues, liver problems, and psychological effects. Its use should only be considered under the strict supervision of a medical professional and when the potential benefits outweigh the risks. Misuse or abuse of this substance can have significant negative consequences on health.