One of the original “Solaray Products” – an Sp Herb Blend containing key herbs and specially selected homeopathic cell salts formulated for specific health benefits – Histamine Blend Sp-33 is formulated to help support a healthy histamine response.Our powerful formula includes a proprietary blend of Montmorillonite Clay, Horehound, Mullein, Wild Cherry, Barberry, and Peppermint. Believed to work better together in a blend, these powerful herbs contain flavonoids, alkaloids, sterols, tannins, and more that are believed to help support a healthy, normal histamine response and respiration. We ve also included cell salt nutrients designed to work synergistically with the herbs in our Histamine Blend.