Tried OvuSense after my wrist-wearables gaslit me for months - continuous vaginal core temp was noticeably better with irregular/PCOS-y cycles. The published data lines up with my experience: decent next‑day prediction (90% PPV) and very solid confirmation of ovulation (99%), but it still hates jet lag and late‑night wine. Inne was “cool lab-in-a-lip-balm,” but saliva progesterone is finicky (strict morning sampling, nothing by mouth beforehand), and the day-to-day noise made it more “is there a luteal phase at all?” than precise timing.
What actually helped my gyn visit: pairing gadget data with labs (CD3 FSH/LH/E2, TSH/prolactin if needed, and a mid‑luteal serum progesterone), plus a symptom log for pain/bleeding (PBAC) and NSAID use. For endo, the pain pattern mattered way more than any temperature curve. Pro tip: mark “artifact days” (fever, alcohol, night shifts, red-eye flights) so your graphs don’t look like modern art. And yes, perimenopause will bully any algorithm.
Future-wise, sweat/saliva multi-hormone patches are promising, but still mostly in shiny-slide-deck territory. Until then, these tools are great decision aids, not diagnoses - think “smart thermometer with receipts,” not a mini gynecologist in a bracelet.