Yes. Federal law requires retailers of drugs containing pseudoephedrine, ephedrine, and phenlypropanolamine to record the buyer's name and address and keep the records for two years (https://www.fda.gov/drugs/information-drug-class/legal-requi...).

While there is no federal law restricting the sale of medications containing Dextromethorphan, a common cough suppressant, US states have started regulating sales of these medications (https://en.wikipedia.org/wiki/Dextromethorphan_regulation_by...). It looks like most of the time, it's an 18yrs and up age restriction.

My guess would be that it's easier for company policy to always scan the ID, even for age verification, instead of having different policies depending on what is being purchased.