Being that Stanoxyl is a DHT-derivative that cannot convert into Estrogen at any dose at all, Estrogen-related side effects are not a concern from Stanoxyl alone.
The main concerning Stanoxyl side effects relate to its nature as a C17-alpha alkylated compound, and the fact that it can be more androgenic than theoretically noted.
It does carry with it all of the other typical and common side effects that all anabolic steroids share as well (such as HPTA shutdown, cardiovascular concerns, cholesterol alterations, etc.).
Potential liver toxicity (hepatotoxicity) is one of the more concerning Stanoxyl side effects, especially if the oral variant of Stanozolol is being used.
This means that individuals should limit their use of oral Stanoxyl to no longer than 4 – 6 weeks.
Androgenic Stanozolol side effects can be a concern as well, as although its androgenic rating is much less than that of Testosterone, many individuals have reported problems with acne, male pattern baldness, and oily skin, etc.