The chemistry of ammonium thioglycolate

Alex00119 Sep, 2023Science

In the 2001 film Legally Blonde, law student Elle Woods wins her first case by her knowledge of the chemistry of ammonium thioglycolate (which she pronounces "ammonium thyglocolate"), something she claims "any Cosmo girl would have known." Solutions containing ammonium thioglycolate contain a lot of free ammonia, which swells the hair and makes it permeable. Thioglycolic acid contained in the perm solution reduces disulfide cystine bonds in the cortex. In a sense, thioglycolic acid removes cross-links. After washing, hair is treated with a mild solution of hydrogen peroxide to oxidize cysteine ??to cystine. These new chemical bonds give the structural rigidity needed for a successful perm.