l-arginine treatment

My mother suffers from hypertension 3 years and nothing has been done so far for each improvement. She took medications yet no sign or recovery. It’s really disappointing. I wanted to ask does anyone here know is L-arginine use for vascular diseases?

L-arginine shows promise in the treatment and prevention of cardiovascular disease including hypertension and other related conditions. Also it is effective in treatment of some forms of male infertility and some kidney disorders and it is helpful in accelerating wound healing in some circumstances. L-arginine has demonstrated some positive immune-modulating and anticancer effects