Testosterone enanthate ("Test E") is a long-acting injectable androgen used to treat hypogonadism, delayed puberty, and certain breast cancers, or for transgender hormone therapy. It increases testosterone levels to treat symptoms like low sex drive, fatigue, and muscle loss. It is typically administered via intramuscular or subcutaneous injection. 

Key Details About Testosterone Enanthate:

• Side Effects: Potential side effects include acne, skin reactions, worsening sleep apnea, and reduced HDL cholesterol. Serious effects can include blood clots or cardiovascular issues.

• Duration: It is a long-acting ester, with effects on sexual interest appearing around 3 weeks and plateauing at 6 weeks. 

• Administration: It is an oil-based, injectable, long-acting compound.

• Uses: It treats men with low or no testosterone (hypogonadism). It is also used in breast cancer treatment and for masculinizing hormone therapy.

• Benefits: It helps increase body weight and, in some cases, treats bone loss.

It works by replacing natural testosterone in the body.