Can herbal supplements be used to self-treat vascular conditions?

No, not really: There are thousands of supplements advertised to do all sorts of magical remedies. Very few supplements have real research studies to show benefits (but manufacturers make claims, based on theories, animal tests, testimonials, chemical similarities, etc... But not on real research). Herbal supplements have not been shown to be successful in preventing or self-treating vascular conditions.

Not related: However a healthy diet is recommended for patients with vascular disease. Ideal body weight, lower blood sugar, increased lean muscle are helpful in risk reduction for cardiovascular events. High fiber is the beginning of better diet.