Allercetin™ Allergy & Sinus is a Bio-Aligned Formula that utilizes natural homeopathic remedies for the treatment of allergies. Allercetin supports multiple body systems involved with hay fever: the respiratory system, sinuses, mucous membranes, histamine inhibition, immune desensitization, and cellular energy. With HistaStop™ -- Homeopathic Histamine & Quercetin.