Raynaud's is scary and confusing. I have learned the safest way to treat it is with Niacin, 500 mgs., about every four hours during cold weather. It causes a flush, meaning, as it opens your blood vessels, you feel warmth and may be reddish in color. Not all Niacin causes a flush, so buy the right brand. Twin Labs brand from the Vitamin Shoppe is the best brand I know. Please read "Niacin, the Real Story" to get the facts. Don't give in to doctors and meds with side effects.