Medical cure-alls and scams are nothing new. The traveling medicine show was a popular way to advertise snake oil and other quack cures in the 19th century, and then there were radium treatments for everything in the early 20th century. Many of us recall copper bracelets, Laetrile, and other "alternative medicines." There's a long tradition of getting rich by taking advantage of the gullible. In the 1920s and '30s, these marketers took advantage of a wonderful new medium to reach consumers: radio.
In 1932, the Federal Radio Commission (later supplanted by the Federal Communications Commission), banished from the airwaves fortune-tellers, mystics, seers, and other people peddling dubious claims, but concern remained about what was fit to air and how to enforce rules about truth in advertising. A 1936 edition of Hygeia, a publication of the AMA, lamented that “no adequate and prompt measures are as yet available to curb venal radio stations from selling ‘time’ to anyone who pays the price.”
And when regulators did catch up with fraudsters, enterprising quacks got creative. By setting up towers and transmitters in small towns south of the United States/Mexico border, a phalanx of fabulists launched their own stations, beyond the reach of many regulations.
These Mexican radio stations broadcast with up to a million watts of power, reaching across the US and beyond. That's how John R. Brinkley advertised his surgery to implant goat gonads in humans, and made a fortune. Of course, the marketing of dubious quick cures continues on the internet. Read about the era of quack cures on the radio at Atlas Obscura.