Hello Doctor, My Doctor Recommended Me Testosterone Undecanoate Oral, I

Hello doctor, my doctor recommended me testosterone undecanoate oral, i used it for about 10 days and it benefited me a lot . Then i quit using it. After two weeks I again started this medication. But now it is not useful at all. I wanted to ask, since its an anabolic steroid. Is it safe to take oral testosterone undecanoate. Thanks