Even today, drug ads say, “Nothing is more effective than (our product.)” It’s nice of them to tell us we’d be better off taking nothing.
At the Indiana State Fairgrounds, there’s a historic Hook’s drugstore. (CVS bought Hook’s) Over a hundred years ago, Eli Lilly Co. made a wide range of drugs we no longer use. Some were worthless, and some were harmful. Many drugs back then contained opium and cannabis, and they required no prescription.
Slightly off topic, but Bayer Heroin, which was pre-50’s was, no doubt, effective. It just had a few undisclosed side effects like life long adiction. 
For an interesting history of drug companies, and particularly what was going on during the 1950s, I suggest ‘Adverse Reactions’ by Thomas Maeder, originally published in 1994. It’s out of print, but you may be able to find a copy in the library (I bought mine from Amazon).
It’s basically tells the story of the 1950s chloramphenicol disaster, and it also discusses the history of American drug companies. It’s a good look at medicine during that era.
My uncle the pharmacist had a drug store that ONLY had drugs–no soap, shampoo, Comet, Clorox, or anything that wasn’t used medicinally in some way–so you could get a medicated shampoo, for instance, for lice or dandruff but you couldn’t get Prell, and you could get a deodorant but it was a super-expensive kind of deodorant for very hard cases. He did buy hair spray in bulk but this was because of my cousins, who were a little older than me and who came of age in the beehive era. He never stocked it at the store but he bought it by the case. (We found a lot of fun things to do with hairspray, like setting it on fire . . .)
In the early '70s he relented, somewhat, and carried one line of cosmetics–Almay, I think–and some other non-medicinal things. By that time he was getting a lot of competitive pressure from the chains, who sold everything. I’ll tell you one difference between the '50s and today, he was at the store every minute when it was open and usually on his feet, 12 hours a day. It was closed Saturday afternoons and Sundays. Once a month his was the “all night” pharmacy and he stayed there all night (buzzer on the door, sleeping on a cot). He rarely took a vacation. He did have other employees but since they weren’t pharmacists, he had to be there. His “retirement” was selling the drug store (it soon closed) and buying a coin-operated laundry.