It is important to remember that herbs are difficult to study in this setting compared with isolated compounds -- likely because their pharmacological and chemical compositions are sensitive to many factors: hour and season of harvest, form consumed (raw powder, alcohol extract, cold water infusion, fat emulsion, hot water infusion, combustion, pyrolysis, essential oil), part consumed (leaf, root, flower, seed), among staggeringly many others. Anyone with experience consuming cannabis or coffee can probably testify to the above
Not to mention that the pharmacologically active compounds in many plants are far from being comprehensively understood, let alone their interactions and dynamics
This isn't to say that every claim about herbs is to be taken seriously. My point here is more that there is no good reason to dismiss the herb itself as a cause yet simply because it's an herb and a fairly mundane one at that. There are easy examples of herbs which have pronounced physiological effects, used for recreation, performance enhancement, as literal poison, to induce labor, to thin the blood -- among others.
Mints are closely related to pennyroyal (Mentha pulegium), which was traditionally (and dangerously because of toxicity) used as an abortifacient. Its mechanism of action is still unknown, so hormone modulating effects seem plausible to me.
I wonder if mentha arvensis has the same effect. Supplements vs mint tea would be another interesting thing to study in future.
pretty tiny amount of peppermint was consumed
FWIW, I had an Indian co-worker who took peppermint oil frequently and said that it was very good for his upset stomach.
Peppermint - Pure-Castile Magic Soap: Cool, Refresh, and Awaken with Invigorating Peppermint
https://www.drbronner.com/products/peppermint-pure-castile-l...
Dr. Bronner invented the peppermint oil soap for soiled diapers
https://www.sandiegoreader.com/news/1978/nov/02/cover-look-f...
Created in California: How Dr. Bronner’s became the soap for every subculture
https://www.latimes.com/business/story/2023-07-12/dr-bronner...
>Perhaps inspired by that experimental ethos, customers have discovered their own unusual uses in the years since Emanuel started mixing gallons of peppermint castile soap out of his Pershing Square tenement apartment in 1948. [...]
>David, Mike and Lisa Bronner grew up in Glendale, not giving much thought to the prospect of one day taking over the family business and generally regarding their grandfather as a bewildering figure.
>“My granddad was always talking about uniting ‘Spaceship Earth,’ and it was kind of sailing over our heads,” David said.
>“He’d be talking to us as if we were all PhD students in religious studies,” Mike said of visits to Emanuel’s home when the siblings were in elementary school. “He was blind, and every once in a while he would say, ‘Are you there?’ and we’d be like, “All-one, Grandpa!’ And he’d be like, ‘Very good. OK, I want you to recite the peppermint bottle.’”
Lisa Bronner: The Poetry of the Lavender Label
https://www.lisabronner.com/the-poetry-of-the-lavender-label
>The label on the quart size of the Lavender Pure-Castile Magic Soap holds the greatest insight for me into his motivations and goals. The Peppermint label records the tenets of his Moral ABC, his guidelines for humanity to find unity and a path forward. But it is the Lavender quart that hosts his poetry, and in that I see his heart. [...]
>"To keep my health! To do my work! To love, to live!"
>"Great peace is found in little busyness."
>"Work well yourself and work for all."
>"Til we rally, raise, unite!"
>"All-One-God-Faith, All-One! Unite!"
>"Lives of great men all remind us we can make our lives sublime."
>"Life is real! Life is earnest! And the grave is not its goal."
>"Let us then be up and doing ... still achieving, still pursuing"
>"In all we do, let us be generous, fair & loving to Spaceship Earth and all its inhabitants."
>"We're ALL-ONE OR NONE! ALL-ONE!"