John Haigh believed he had concocted the "perfect murder," until forensic science caught up to him in 1949 Sean Neumann is a reporter at PEOPLE. He has been working at PEOPLE since 2019.

Glycolic acid is a substance that chemically exfoliates a person’s skin by dissolving dead skin cells and oils. Glycolic acid may also help boost collagen production, and support skin moisture.

Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States ...