https://techcrunch.com/2019/10/31/femtech-startup-inne-takes-the-wraps-off-a-hormone-tracker-and-8-8m-in-funding/

“The beauty about hormones is they do not get influenced by lack of sleep, they do not get influenced by getting out of your bed — and this is the reason why I wanted to opt to actually measure them,” she adds, saying she came up with the idea for the product as a user of natural contraception searching for a better experience.