Ionic is a chemical Japanese hair straightening treatment designed to straighten curly or frizzy hair, without using heat. This treatment seals down the hair's cuticles, to eliminate frizz. The result is straight hair, without being completely flat. 3. Which is better ionic or ceramic hair straightener? Ionic” flat irons are better than ceramic flat irons. The word “ionic” is commonly used in the styling industry to refer to negative ions only. Ceramic flat irons use ceramic heaters, which produce negative ions when heated - no matter what. An ion is an atom that's gained a positive or negative electrical charge. 2. What are ionic hair straighteners? Ceramic Hair Straighteners vs Ionic Hair Straighteners An ionic hair straightener again delivers the same advantages as an ionic dryer, releasing active ions that surround your hair to give a shine boost with every pass, eliminating static and taming the dreaded frizz. 4. What is the healthiest hair straightener?