How to use Cymex Cream Repeat every hour until the cold sore fades so your lips can feel smooth & supple once more. How Cymex Cream works to relieve cold sores Cymex Cream’s triple action formula actively relieves, controls infection & promotes effective healing of painful unsightly cold sores & dry cracked lips. Urea – softens the outside layer of the skin Dimeticone – keeps the skin moisturised & helps prevent scabs from cracking Cetrimide – is an antiseptic which helps prevent further infection of the broken skin Chlorocresol – also an antiseptic which helps prevent further infection of the broken skin