Vintage ads can be both hilarious and shocking, and some of the most often passed around old ads are these ones about women using “‘Lysol’ brand disinfectant” for “feminine hygiene.” The ad had women claiming, “I use Lysol always for douching.” At the time, Lysol was “an antiseptic soap whose pre-1953 formula contained cresol, a phenol compound reported in some cases to cause inflammation, burning, and even death,” says Mother Jones, and the thought of using that for douching is enough to make anybody wince.

But according to Lisa Wade at The Society Pages, that’s not actually what the ads are pushing. She writes:

These ads aren’t frightening women into thinking their genitals smell badly. According to historian Andrea Tone, “feminine hygiene” was a euphemism. Birth control was illegal in the U.S. until 1965 (for married couples) and 1972 (for single people). These Lysol ads are actually for contraception. The campaign made Lysol the best-selling method of contraception during the Great Depression.

Of course, as Wade points out, this still wasn’t a good idea: Lysol might have been corrosive to the sperm but it also damaged tissue inside the woman. And in fact the Lysol used back then was far stronger than our Lysol is today. Hundreds of people died from Lysol exposure, some of them women using it as birth control. Nicole Pasulka at Mother Jones writes:

By 1911 doctors had recorded 193 Lysol poisonings and five deaths from uterine irrigation. Despite reports to the contrary, Lysol was aggressively marketed to women as safe and gentle. Once cresol was replaced with ortho-hydroxydiphenyl in the formula, Lysol was pushed as a germicide good for cleaning toilet bowls and treating ringworm, and Lehn & Fink’s, the company that made the disinfectant, continued to market it as safeguard for women’s “dainty feminine allure.”

As if that wasn’t bad enough, Lysol isn’t even an effective contraceptive.

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