No charting, no strips, no apps to interpret. Daysy does the work, you read the result.
The moment you wake, before getting out of bed, place Daysy under your tongue and press the button. The sensor reads your basal body temperature to ±0.05°C.
Daysy vibrates when it's done. The reading syncs to the free DaysyDay app via Bluetooth automatically. No strips, no charting.
A light tells you where you are in your cycle. The algorithm, refined since 1986 on millions of cycles, decides which.
Basal body temperature rises by about 0.5°F right after ovulation. Detecting it requires the right place (under the tongue), the right time (the moment you wake), and the right precision (±0.05°C).
Wrist and finger wearables read skin temperature, which drifts with the room, the blankets, and your activity. Daysy gives you the day.
Read the science behind the differenceDaysy is designed for cycles between 19 and 40 days. If your cycles usually fall in that range, even irregularly, Daysy will learn them, typically in 2 to 3 full cycles. Women with PMOS and postpartum return-to-cycle are some of our longest-running customers. Take the 2-minute fit check if you want a personalized answer.
No. Daysy is $249 during the Spring Sale (regularly $299), one time. The DaysyDay companion app is free, forever. No refill strips. No tiered features.
Typically 2 to 3 full cycles. During this time the algorithm learns your specific patterns. If after two full cycles your results aren't stabilizing, our 30-day money-back guarantee means a full refund.
No. Daysy is a cycle monitor, a tool for observing where you are in your cycle. It is not classified or marketed as a contraceptive device. Read the full honesty page.
Spring Sale price through May 31. No subscription, ever. Free US shipping. 30-day money-back guarantee.
Add Daysy to cart · $249Ancient knowledge married with modern technology.