Want to stay masculine. Should I buy online testosterone patches (hormone replacement therapy)?

Online testosterone. Male androgen replacement for documented hypogonadism should always be prescribed and managed by a knowlegeable and licensed physician. Doing anything other than that is foolish, illegal, and down right dangerous.
Absolutely not. I do not recommend purchasing any medication online, especially hormones like testosterone. If you have been suffering from signs and symptoms of low testosterone, the best strategy is to see your doctor. If signs/symptoms plus blood tests reveal testosterone deficiency or inadequacy, there are several types of HRT available, including patches, troches, creams/gels, injections, and pellets.