The reducing agent in alkaline permanent waves is which chemical?

• A. Sodium thioglycolate
• B. Ammonium thioglycolate
• C. Guanidine carbonate
• D. Hydrogen peroxide

Answer: (B)

In alkaline permanent waves, the reducing agent’s job is to break the hair’s disulfide bonds so the cortex can rearrange into a new shape. The reducing agent used is ammonium thioglycolate, a thiol-containing compound that provides the necessary electrons to cleave those bonds while the hair is in a highly alkaline environment. After the hair is set on rods, a neutralizer then oxidizes the thiol groups back to disulfide bonds, locking in the new wave or curl. Among the options, ammonium thioglycolate best fits this reducing role in alkaline perms. Sodium thioglycolate is a related reducing agent but not the standard for alkaline waves in typical practice. Guanidine carbonate is linked to other relaxer systems and not the reducing agent for alkaline perms. Hydrogen peroxide is the oxidizer used in the neutralizing step, not the reducing agent.