Trying to conceive?

OVU Control tells you when it's the right time to try!

Ovu Control is a reusable, saliva-based method of detecting ovulation with 98% accuracy. It has been used in over 70 countries and is continuing to help families on their journey to get pregnant.

Compared to a traditional LH urine strip, a saliva-based ovulation predictor is:

  • Simple - All it takes is a dab of saliva on microscope

  • Economical - Take unlimited tests with this reusable device just for the cost of 2 months of traditional urine strips

  • Accurate - Clinically equivalent to urine strips
  • Hygienic - No urine required


  • Scientifically tested saliva-based method ('ferning phenomenon') for assessing a woman's saliva sample
  • Contains mini-microscope (50-fold magnification)
  • 100% discreet design
  • Can be used anywhere
  • Reusable
  • Clinically tested
  • Includes cleaning cloth for microscope lens

During a woman’s fertile days, LH increases cause elevated quantities of electrolytes. This results in ferning - or the crystallization of dried saliva - which can be seen under a microscope. Ovu Control will help to track your entire menstrual cycle, which will help you time the 6 days that you are fertile after you see positive results.

What you will see in the microscope:

The salt crystals that form in dried saliva have a fern-like structure. This ‘ferning pattern’ can be seen most clearly directly before ovulation. During the infertile days this ‘ferning pattern’ disappears, owing to the increasing level of progesterone, and a gravel-like pattern is seen instead. 


What physicians are saying...

I was impressed by the elegant design and the simplicity of the Ovu Control device which is able to provide detection of the fertile period for women based on the physiologic effect of estrogen in the saliva. The absence of any reagents, and the ability to reuse the device on a daily or monthly basis, makes it extremely economical compared to urinary LH detection strips.
— Dr. Robert Casper | Professor, Department of Obstectrics & Gynecology | University of Toronto
It’s nice to see a company specializing in quality family planning products. I am especially impressed with the accuracy, ease of use and economical value of both the Ovu Control fertility predictor and Early Detect pregnancy test. Geratherm has truly taken today’s women into consideration!
— Dr. Grace Liu | Obstetrics & Gynecologist | Sunnybrook Health Sciences Center / Women's College Hospital

Featured in the Wall Street Journal

Reusable Ovulation Predictors!

Frequently Asked Questions

1. How does Geratherm® Ovu Control work?

Geratherm® Ovu Control detects hormone changes that occur prior to and during ovulation. There is a direct correlation between the increase in LH (luteinising hormone) levels and the time of ovulation. During a woman’s fertile days, the salt content in the saliva rises owing to the increased LH production. The salt crystals that form in dried saliva have a fern-like structure. This ‘ferning pattern’ can be seen most clearly directly before ovulation. During the infertile days this ‘ferning pattern’ disappears due to the increasing level of progesterone, and a gravel-like pattern is seen instead.

2. Is Geratherm® Ovu Control accurate?

When instructions are followed, determining fertility through ovulation microscopy has been shown to be 98% accurate.

3. Does the fern structure look the same for all women?

No. As the LH increase varies, not only from cycle to cycle, but also from woman to woman, an unique crystallisation pattern is detected for each woman.

4. When do I test with Geratherm® Ovu Control?

Test on a daily basis, preferably morning right after getting up, before eating, drinking, smoking, brushing teeth, etc. If you test later in the day, try to wait at least three hours after eating, drinking, brushing teeth or smoking. Record your results on a fertility chart or calendar. Carefully recorded data provides important diagnostic information. You should always take your data with you when you visit your doctor. Start recording on the first day of a menstrual period.

5. How many times can I use the fertility tester?

The Geratherm® Ovu Control is reusable. There is no other expense, other than the batteries, which may eventually need to be replaced.

6. How do I apply a saliva sample?

A sublingual saliva sample, collected from below the tongue will provide the best results. Place a drop of saliva on the middle of the lens using a clean and dry finger. Dab the saliva onto the lens from above, without smearing the drop. Ensure that no air bubbles or foam are on the lens. Leave the saliva sample to dry at room temperature for about 10 to 15 minutes. Note: You can stimulate the production of saliva by biting gently on your tongue.

7. Can I dry the saliva sample with tools such as a hairdryer?

No. The use of any device to dry the saliva sample may damage it. The sample can become distorted by blowing or get contaminated with foreign objects, this could lead to a misinterpretation of the results. If you are in a hurry in the morning and cannot view the sample, let it dry as long as required and then view it at a later point.

8. Will breast-feeding affect my results?

Yes, if you are breast-feeding your results could be inaccurate. This is due to hormonal changes in your body.

9. What can interfere with results?

Anything that affects LH levels in the body may affect the results. Changes to the ‘ferning pattern’ can be caused by the following:

  • After discontinuing the use of hormonal contraceptive agents (e.g. ‘the pill’)
  • During use of hormone supplements (e.g. ‘the pill’) or other specific medications.
  • After a birth, during and after lactation.
  • Medical conditions or products which alter the composition of mucus secretions (e.g. expectorant medications) High LH levels may produce an ongoing ‘ferning pattern’ while low LH levels may not be picked up by the microscope. In this situation, please contact your doctor.