Frequently Asked Questions

1. Who can use femSense? (Is it right for me)

femSense is suitable for fertile women who bleed and ovulate. If your cycle is between 21 and 35 days and the cycles do not differ more than +/- 3 days: femSense is for you!

If your menstrual cycle is irregular, then femSense cannot reliably predict your fertile window. In this case we recommend that you consult a doctor before choosing femSense.

While we would love for femSense to be suitable for everyone, it is important to note that this may not be the case. We encourage you to review the following information to determine if femSense is the right for you.

If you have sensitive skin or allergies to medical-grade adhesives, the femSense sensor patch may not be suitable for you. However, you can still use the femSense app as a period and symptom tracker.

If you have irregular cycles or infrequent/absent menstruations, femSense relies on a regular cycle to accurately calculate the patch application day, so it may not be effective for you.

Weight conditions (underweight or overweight) can increase the risk of adhesion issues or skin irritations with the patch. If you have a BMI lower than 18.5 or higher than 30, femSense may not be right for you.

Keep in mind, excessive consumption of nicotine or alcohol can impact body temperature and potentially affect the accuracy of femSense in detecting ovulation.

femSense is not ready to support medical conditions such as PCOS. If you do not have a menstrual cycle between 21-35 days or take medications that affect body temperature, femSense may not be suitable for you.

If you are unsure whether femSense is suitable for you, please contact your doctor or get in touch with our technical support via e-mail to:

2. How does the femSense patch work?

The femSense System consists of a very precise temperature sensor embedded in an adhesive patch and the supporting app.

The sensor patch is worn underneath your arm.Once activated the patch measures the body temperature continuously, 24/7, for up to 7 days.To work correctly the patch should be read by your NFC capable smart device at least once (1) a day. The app will ask you to read the patch twice (2) a day for optimal evaluation.femSense tells you when you are fertile and, based on the recorded temperature data, femSense can detect and confirm ovulation.Every month the app reminds you when to apply the patch, when to read the patch, and when you are fertile.

3. How does femSense know when I am fertile?

femSense reliably detects your ovulation and most fertile days using continuous temperature measurement and the well-known temperature method.
Based on your previous periods the femSense app can predict your fertile window, the days you are most likely to get pregnant. The femSense sensor patch measures your body temperature continuously, 24/7 during your fertile window to measure and confirm your ovulation. You are fertile in the days shortly before and immediately after ovulation.

4. How accurate is femSense?

The temperature sensor used in the femSense patches detects temperature differences smaller than 0.1°C and was especially designed to detect the postovulatory temperature rise, which is typically between 0.2°C-0.5°C.
In contrast to the basic basal temperature measurement method, the patch records a temperature value several times per hour. As the patch is always in the same position, measurement artifacts can be minimized.  A clinical study with the medical university in Graz proved the accuracy of the sensor patch and now an independent Swiss statistics institute has confirmed that femSense is 99.73% accurate when predicting ovulation.

5. How many patches do I use per cycle?

You can use one patch per cycle. After applying and activating a patch according to the in-app instructions, the patch is associated with your current cycle.

6. Can I shower or bathe with the patch?

Of course, you can shower while wearing the patch. The patch is designed in such a way that daily body care is possible. However, long baths and sauna sessions should be avoided, as the warm environment can reduce the adhesive strength of the patch (as with any other skin patch), which could cause it to peel off prematurely.

7. I’m allergic to medical grade tape, can I use this?

The femSense Patch is made of hypoallergenic materials used in medical wound care. However, some people with very sensitive skin may still react to the patch or the adhesive. Symptoms such as itching, burning, redness or slight skin swelling may occur. In this case please remove the patch and apply a soothing ointment to the area.If you are unsure whether femSense is suitable for you, please contact your doctor or get in touch with our technical support via e-mail to:

8. Can I work out with this?

Of course, but as with any common bandaid, adhesiveness may be impacted depending on the amount and exposure to sweat/water/heat. Having said that, the tech inside the patch won't be impacted at all.

9. How many patches come in the box?

Each box contains 1 femSense patch.

10. Are there any contraindications for using the patch?

Certain medical conditions do not allow femSense to reliably measure ovulation. These include:

  • Serious, acute or chronic diseases
  • Nicotine or alcohol abuse
  • Amenorrhea Oligomenorrhea (too infrequent menstrual bleeding)
  • Polycystic ovary syndrome (PCOS)
  • Obesity (BMI > 30)
  • Hirsutism
  • Known allergy to components of plasters or adhesive Medication that can influence your body temperature
  • Hormone treatments (e.g. pill, hormone injections, IUD, etc.) may affect body temperature

Extreme weight conditions can affect the reliability of femSense. If you are not sure whether femSense is suitable for you, please consult your doctor before beginning use.

Still Have Questions?

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