Birth control can be confusing and overwhelming. Some people have risk factors that make traditional birth control methods, like the pill and the IUD, less optimal.

Those seeking a natural, hormone-free birth control method may be interested in Daysy, a fertility tracker designed for people who want to conceive. Some people are interested in Daysy as an alternative to hormonal birth control or a supplement to family planning tools.

Here’s what you need to know if you’re considering using Daysy.

Daysy is a small medical device that functions as a fertility tracker. It uses your daily temperature to track when you’re most fertile or most likely to conceive during your cycle.

The small device takes your temperature each day and pairs with a free app, where you can view information related to your fertility.


  • natural and hormone-free, so there are no side effects
  • easy to use
  • helps predict ovulation


  • must be used daily
  • Users often experience technical difficulties.
  • If used to prevent pregnancy, it’s less effective compared with traditional contraceptive methods.
  • Fertility tracking based on body temperature isn’t fool-proof

Anyone with a female reproductive system can use Daysy. While it’s designed to help users conceive, some people like using Daysy’s fertility tracking features as part of their natural birth control method. Daysy, in general, can be a good resource for those looking to learn more about their fertility.

Knowing when you’re fertile may help increase your chances of conceiving if that’s your goal.

Daysy may be an option for those looking for hormone-free birth control.

Daysy works by increasing your fertility awareness. This is the awareness of the days you’re fertile, so you can make family planning decisions accordingly. During your fertile window, you’re more likely to conceive a pregnancy than on the days outside your fertile window.

It uses your basal body temperature and menstruation data to calculate when you’re more likely to conceive and when you’re less likely to conceive. Daysy takes your temperature using a precise sensor, stores your data, and calculates your fertility status.

Daysy signals the fertility status using the lights on the device:

  • Red means you’re more likely to conceive.
  • Green means you’re less likely to conceive.
  • Red flashing lights indicate the predicted day of ovulation.
  • Yellow lights can be an indicator of cycle fluctuations or potentially fertile days.

Powered by a self-learning algorithm, Daysy is designed to reduce the potential for user errors or account for factors like stress and travel. It’s based on a database with over 5 million menstrual cycles and 500,000 users to draw data from, according to the company.

Daysy is simple to use, but it must be used every day. And even then, it’s not a fool-proof method. In this way, it’s similar to the pill, which must be taken daily and around the same time each day. It’s OK if you forget to take a measurement every now and then, but your results will be most accurate with consistent daily use.

You’ll use Daysy first thing in the morning before you get out of bed. It’s recommended to get at least 3 to 4 hours of sleep before using Daysy.

To use Daysy:

  1. Press the activation button once to view your predicted fertility status. Press it again to begin taking your temperature.
  2. Remove the protective cap over the sensor and place the sensor under your tongue. Do this while lying down, and don’t engage in any activities before this step.
  3. The device will beep when the measurement has been recorded.

Part of using Daysy involves recording menstruation. When you’re on your period, press the activation button until a violet light appears and the device beeps once.

In the beginning, Daysy will be in the learning phase. Expect to see a lot of yellow lights as Daysy’s algorithm learns more about your fertility. The more you use Daysy, the more it learns about you.

Daysy is available to purchase on the company’s website,

It’s also available on:

Daysy is rated highly on TrustPilot and Amazon. Customer reviews praise the company for good customer service and warranty. Many customers write about their positive experiences using Daysy to prevent or plan a pregnancy.

“This a great alternative if you [are] trying to avoid hormonal birth control,” writes Amazon user Stori Evans. “I am still learning about this device, but after a while, you get the hang of it. It has also helped me learn more about my body.”

Other reviews aren’t so positive, saying the company has faulty products, glitches in the app, and expensive prices. Users have reported experiencing technical difficulties with the device and app.

“It never syncs properly with the app. You have to continue doing it over and over [until] it finally works. When I input information, half the time it doesn’t save. It takes about 2 minutes for it to take your temperature,” explains a reviewer on TrustPilot.

A common complaint among users is the high frequency of yellow days, which indicate potentially fertile days, or that the Daysy is still learning. Some reviewers mention they still became pregnant despite using the device to prevent unwanted pregnancy. That being said, the device is not marketed towards pregnancy prevention.

There are no side effects of using Daysy. It’s as safe as taking your temperature with a regular thermometer. It’s also registered with the FDA.

PricingInsurance coverageMain features
Daysyone-time fee of $299may be reimbursed by some insurance plans and eligible for HSA and FSApowered by a self-learning algorithm to predict days of fertility and ovulation
Mira$199 for the starter kit and $40.50 for a 20-pack of fertility wandseligible for HSA and FSAuses a device to analyze ovulation strips and relay personalized information about your fertility
Tempdrop Fertility and Ovulation Trackerone-time fee of $199health insurance not acceptedwearable sensor pairs with app

Fertility and family planning are complex, so there’s a wide variety of birth control methods out there. Birth control can be used to prevent unwanted pregnancy, but some family planning tools can also help those who wish to conceive.

The best option for you depends on your goals, and there’s a possibility that Daysy may not be a fit for you. However, there are other natural birth control methods to consider.

A popular alternative to Daysy is simply tracking your cycle and taking your temperature yourself. Tracking and understanding the rise and fall of your basal body temperature throughout your cycle can help you predict the days you’re fertile.

Daysy does this for you, but doing it yourself is an option if you have trouble with the app or want a budget-friendly option.

If the fertility awareness associated with Daysy is what intrigues you, consider the rhythm method. This involves tracking your menstrual cycle and using the data to predict future cycles and gain a better awareness of your body.

Additionally, Phexxi is a newer nonhormonal birth control gel, available by prescription, that’s placed inside the vagina just before penis-in-vagina sex to reduce the risk of pregnancy. It works by preventing semen from changing the pH of the vagina.

If you’re sexually active and not interested in conceiving a pregnancy, contraception should be on your mind. There are many options to use.

Hormonal contraception is generally considered safe and well-tolerated with minimal or no side effects for the majority of users.

There are some people, however, who may have risk factors, health conditions, or sensitivities that make them more prone to side effects from hormonal birth control methods.

Birth control side effects vary depending on the type and your body.

Common birth control side effects include:

  • missed periods
  • spotting
  • acne
  • breast tenderness
  • nausea
  • headaches

They can also have health consequences, like increased blood pressure.

Natural options, like Daysy, can help you track your fertile windows, are free of side effects and health risks, making them safer.

Getting started with Daysy is simple.

You can start by ordering your Daysy tracker and downloading the app. Before the first use, you’ll need to charge the device. After that, you’ll need to charge it using the USB cable every 1 to 2 months.

Daysy comes with everything you need, so you don’t need to purchase anything else. Unlike other birth control methods, you don’t need to purchase supplies on a monthly basis.

Consult your doctor if you’re taking any medications that affect your body temperature. This can interfere with the effectiveness of Daysy.

If you’re currently using other forms of birth control given to you by your doctor, check if Daysy is compatible with your existing method. Daysy should not be used while on hormonal birth control.

How effective is Daysy?

Daysy claims to be 99.4 percent accurate. This was confirmed by a study funded by the company. In 2018, unaffiliated researchers found that Daysy wasn’t as accurate as the company claims, and the company’s article was retracted shortly after in 2018.

A new study funded by the company in 2020 also found the device to be 99.4 accurate in distinguishing fertile days from infertile days, and still stands.

Does insurance cover Daysy?

Daysy doesn’t accept health insurance as a form of payment, but you may be able to get a portion of the cost reimbursed by your health insurance plan.

It’s also eligible for health savings accounts (HSAs) and flexible spending accounts (FSAs).

Is Daysy worth the money?

Daysy is pricey, but it’s a one-time expense. Over time, it may be less expensive than ovulation test strips, birth control pills, IUDs, and other forms of birth control and family planning resources.

If you’re looking for a natural birth control, it may be worth the money to you, but this is subjective.

Can you still get pregnant when you’re not ovulating or when you’re on your period?

You can still get pregnant on your period and outside of ovulation, but this is rare. You can also still get pregnant on birth control.

For those looking for a natural birth control method, Daysy is a suitable option. It’s easy to use, free of side effects, and reliable. Though it requires a hefty upfront investment, it may be more cost-effective over time.

If Daysy isn’t right for you, there are many other birth control methods, from conventional condoms to other natural or nonhormonal birth control methods.

Everybody is different, so it may take some trial and error before you find the right birth control method for you.

Lacey Muinos is a health, wellness, and beauty writer based in Southern California. She holds a BA in English. Her work has appeared in digital publications like Livestrong, Verywell, Business Insider, Eat This Not That, and others. When she’s not writing, Lacey is likely pursuing her other interests: skin care, plant-based cooking, Pilates, and traveling. You can keep up with her by visiting her website or her blog.