Daysy tells you when you are in your fertile window and when not. Daysy is not a contraception.

Natural fertility awareness 


Sex is one of the most delightful things in the world. However, there is always the possibility of becoming pregnant unexpectedly, if contraception is not used. If pregnancy is a risk, it can make sex less enjoyable. The use of condoms is always a good option - also to protect against sexually transmitted diseases - but those who are in a committed relationship may no longer want to use a barrier method with their partner, and prefer to have unprotected sex. The alternatives are often to use a coil, a diaphragm or an implant or, as is most common, to take the pill. However, all forms of hormonal or invasive contraception have side effects, from those that lower quality of life to the life threatening.

To change this and enable women like you to deal more naturally with their fertility, we have developed fertility tracker Daysy: Daysy can tell you when you have your fertile window.


Quick, reliable and proven: You can rely on Daysy’s algorithm

Unlike other methods, Daysy makes it easy to find out with certainty whether you are in your fertile or infertile phase. The simple and intuitive operation of Daysy lets you know the current status of your fertility within seconds. All you have to do is measure your basal body temperature under your tongue with Daysy in the morning immediately after waking up and before getting up. In addition, you enter whether you have your period. Based on your data and those from 5 million menstrual cycles and 30 years of research, Daysy's algorithm calculates within seconds and whether you are fertile or not.


With these 3 colors you can keep track of your cycle and fertility

  • If Daysy shows you a green light, you are not fertile.
  • If Daysy shows you a red light, you are fertile. In this case, you will also need to use a barrier method to prevent pregnancy, e.g. a condom. Or you can postpone PIV (penis-in-vagina) sex on these days.
  • Yellow days indicate cycle variations. They can also mean that Daysy is still in the learning phase. To avoid pregnancy, you should treat yellow days like red days and use an additional barrier method or postpone PIV sex.


At a glance: Why Daysy is ideal for fertility tracking

One of the advantages of Daysy is the ability to explore your own cycle and get to know your body better. Apart from the simple measurement of your basal body temperature in the morning and the input of your menstruation days, nothing else is necessary so that you can become aware of your cycle and body. But please remember that Daysy itself is not a contraceptive, but rather indicates when you need to use a contraceptive like a condom. (Please keep in mind that you can protect yourself from sexually transmitted diseases only by using condoms, too)

Find your own personal relationship with your body. Know your cycle, know yourself!


290.00 EUR

incl. VAT and Shipping

Daysy calculates your fertile window: Your fertility status will be displayed either as a red (you are fertile) or green (you are not fertile) light.

Daysy calculates your fertile window: Your fertility status will be displayed either as a red (you are fertile) or green (you are not fertile) light.

  • Fertility tracker Daysy (incl. battery)
  • Connection cable for your smartphone
  • Instructions for use

Product available - Delivery time: 3-5 days*