What Is The Dosage Of L-arginine?

1.) My husband is 76. He has been prescribed Lisinopril 10mg for over 3 years. I believe it is affecting his skin, making it thin and susceptible to bruising and bleeding. Is there anything else that he could take that would not adversely affect his skin? What would happen if he stops taking it? 2.) Would it be wise for him to take L-argenine? What dose?