Ovulation Predictor Kit- Urine vs Saliva Ovulation Test
We all know that understanding ovulation cycles is the first and most important step when you are trying to conceive. The most common question we’ve seen is which ovulation predictor kit (OPK) would I choose. Most of the OPKs in the market can be classified into two categories: traditional urine strip tests and saliva fertility tests. Both types of tests claim high accuracy and the ease of use, while they have many obvious differences. In this post, we share with you on in-depth comparison of them and help you understand which product is better choice for you.

How Ovulation Predictor Kits Work

Urine ovulation tests predict your ovulation period by utilizing chemical reactions to measure the luteinizing hormone (LH) amount in the urine, which surges significantly before ovulation days. Users need to urinate in a container to do the test, which could be messy sometimes.
Saliva ovulation predictor kits allow you to observe a ferning pattern caused by the increased estrogen level in the saliva, which happens closer to ovulation. Users are able to see the results simply by using a fertility microscope. It’s easy to use and the results are clear and accurate.

Pros & Cons of Urine and Saliva Ovulation Predictor Kits

Both types of test have their pros and cons when it comes to the effectiveness, ease of use, price, etc. There are some main differences between these two types of OPKs, and you can see the complete comparison chart at the end of the article.

  • Although the average unit price of urine tests is cheaper than saliva ovulation tests, saliva OPKs actually cost less. A saliva OPK is about 60 dollars and can last years with daily use, while urine strips are 2-4 dollars and require a monthly purchase. Saliva ovulation tests are more environment-friendly.
  • Fertile drugs and medications would influence the LH level in the urine and invalidate your test results. Smoking and eating can affect saliva ovulation tests by changing the salt level, which is also influenced by estrogen hormone, in the saliva; however as long as a user follows the instructions, saliva OPKs can be 98% effective even with medications.
  • Compare to the clear ferning pattern you can see from the saliva test results, the results on urine sticks sometimes are hard to read. You may need to practice and learn how to read the results correctly at the beginning.


To learn more difference between the two tests, please read Is a Saliva Ovulation Kit Better Than Urine? on Modern Mom.

KNOWHEN® Saliva Ovulation Predictor Kit Versus Urine Strips

  KNOWHEN® Ovulation Predictor Kit Urine Strips
Usage One-time purchase Require monthly purchase
Cost Less than $60 lifetime Have cheaper unit price but cost more when you need to buy multiple times.
Effectiveness 98% effective with or without medications May not be effective with other medicines. Result errors are very high if users are taking fertility drugs.
Ease of Use Uses a drop of saliva with the finger – it’s discreet Requires coordination. Tests need to be scheduled around the time of urinating.
Education Empowers with answers to question woman need to know to better understand her body. Comes with educational CD. Allows a woman to gouge and track her ovulation for one year before investing time, money and emotion to consult a fertility specialist to conceive. No such accompaniment. Possible misleading information won’t help a woman understand ovulation better.
Ovulation Tracking App Comes with free personalized online tracking mobile app with purchase of device. Saved data is secure even if the computer/phone device is lost or damaged. Tracking ability helps the user to have a more educated relationship with her doctor or specialist reviewing a 1-year history together to unearth patterns or issues. Usually don’t come with a tracking system.
Packaging CD education, fertility microscope, personal ovulation app, instructions, lens cleaning cloth, fertility chart and attractive feminine carrying case (like a lipstick case). 5 or 7 packaged urine strips and instruction leaflet.
Use of Chemicals 100% natural Contain chemicals to perform the test.
Shelf Life Lifetime use of device 1-year expiration date
Scope of Ovulation Reporting Provides entire ovulation cycle allowing for daily check, which provides a full picture to the user. Provides the best 5 days in the ovulation cycle to conceive. Show only 2 days in the cycle to conceive.