From what I can tell, skin-care experts are still pretty split on whether or not we need toners.
Dr. Mona Gohara, a clinical dermatologist and consulting dermatologist for Dove, says, "I don't often recommend toners. My feeling is if you use the right cleanser, you don't need this additional step." Cosmetic surgeon and cofounder of Avya Skincare Dr. Tanuj Nakra agrees, saying, "[I also] would not recommend using toners. The astringent properties of toners strip the skin's natural oils, which can have substantial consequences for the skin. There are more modern and gentler ways of addressing acne, oiliness, as well as pore size."
While some experts vehemently recommend to use or not to use toners, some others argue that while they're not necessary, they can be a welcome addition to a skin-care regimen. Dr. Parvaneh Rafaeloff, general physician and medical director at Le Jolie Medi Spa, says, "While toners aren't necessarily mandatory, they can help keep the skin clean and prep it to be an optimal blank canvas for serums, treatment products, and moisturizers."
Note that Gohara, Nakra, and Shelger all refer to toners in the traditional sense — as formulas that either further skin cleansing or help with combating oiliness and imbalance — while Tsai's definition of toners is rooted in Asian skin-care routines that promote balancing and hydration.
