The length of time it takes lactic acid to work depends on the product and the intensity of the chemical peel.
DermNet NZ states that AHA peels can take a few months to work.
The AAD states that after a professional chemical peel, a person will notice results once the skin has healed. This can take between 1 day or 14 days, depending on the intensity of the chemical peel.
If a person has undergone a refreshing peel, they may require 3–5 sessions.