Fertility tracker and hormone-free birth control method: 5 months with Daysy review

Quitting the pill is a series of essays where I explore femininity, my cycle, natural birth control, connecting to my womb wisdom and living in tune with the natural rhythms of my body. Daysy (€299) is a smart thermometer that tracks your menstrual cycle and identifies your fertile days. I’ve been using Daysy for 5 months and I am happy with the increased awareness of the natural rhythms in my body.

You can use Daysy as a fertility tracker or as hormone-free birth control, by having intercourse on the infertile days and using a barrier method like a condom on the days you are fertile.

Every morning, right after waking up, you turn on Daysy and an indicator light flashes:

  • Red: you are fertile
  • Blinking red: you are ovulating
  • Green: infertile
  • Yellow: Daysy needs more (frequent) measurements and can’t give an accurate prediction.
  • Blinking violet: Daysy thinks your period will start. If your period has started, you need to confirm this by holding the round button until the violet stays on.
  • Violet: you are menstruating

After checking the light, it’s time to enter the data. You press the center button and a blue light ring activates. Press again and the activation ring will rotate clockwise. Then you put the thermometer under your tongue and wait until Daysy beeps twice. This signals that the measurement finished and Daysy confirms your fertility status.

Daysy View is the app connected to the device. On the app you see a calendar overview of your cycle, temperature and other visual representations of your menstruation. You connect Daysy to your smartphone with a cable that goes into the headset plug of your phone.



Accurate Period Prediction

The period prediction is super accurate. I’ve become very aware of how my mood and energy levels change running up to my period. I notice an increased appetite, I turn more inward and don’t feel like doing ‘yang’ type of activities like going out.

Increased awareness of my natural rhythms

I love how I have become more intimate with the way my body functions and how I can use it to my advantage. Leading up to ovulation, I feel super energised and I know I can go hard and do lots of things. I need less sleep and I am crazy motivated to hustle. After ovulation, I slow down and turn more inward. I used to feel guilty about this, but now I can just follow my own natural rhythms, because I know it’s part of my cycle.

Super easy to use

The manual to Daysy is straight-forward and clear. The way it’s designed and how you input the information is very easy.

The only thing you need to get used to is taking your temperature first thing in the morning. As I keep Daysy next to my alarm clock, I am immediately reminded to take my temperature. Only when I’m travelling and keep it somewhere else, I tend to forget it.

No hormones

I’ve been off birth control for almost 3 years now and I don’t ever want to go back. I have a deeper access to my intuition and inner guidance system. I flow with my natural rhythms and I love working like that. In the long run it’s cheaper than using hormone-based birth control methods and better for the environment as there is no waste. 


Always showing red lights

I started tracking my cycle with Daysy on 14 November 2018. What I’ve noticed is that it only took a month of daily measurements for Daysy to start showing the red and green lights, but almost 75% of the time it’s a red light. I don’t know how accurate this is, but I guess better safe than sorry.

When you don’t measure for more than 3 days in a row, which happened while I was travelling earlier this year, she shows a lot of yellow lights for at least a week.

Not reliable enough to use as anti-conception

One of my followers shared that 2 of her friends shortly got pregnant after using Daysy for 6 months in a committed relationship with regular intercourse. Fortunately, they were in a place where having children was an option, but not so soon.

If you want to go full on natural hormone-free birth control, next to your daily temperature, you also need to track:

  • Cervix mucus/discharge every day
  • Cervical position
  • Other symptoms: libido changes, sensitive breasts, ..

Do you use a fertility tracker? What are your experiences? Let me know!

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