100% L-Ascorbic Acid Powder O9

Because it’s made of 100 parts per hundred vitamin C, it’s designed to be mixed with other serums, creams, or moisturizers in your skincare routine—allowing you to create a custom vitamin C treatment. 100 parts per hundred L-Ascorbic Acid Powder is a powdered form of direct vitamin C that visibly reduces signs of aging by brightening and balancing uneven skin tone and protecting your skin from damaging environmental stressors.

A cleaner reading of the source-backed description is set out here: depending on your mixture, your combination may delivers a high concentration of direct vitamin C and, as a result, a very strong tingling but non-irritating sensation is expected during the first 1-2 weeks of use until the skin's tolerance to such high exposure is elevated.