Yes, depending on your PCOS. The only difference is that you’ll typically need more than one month to learn about your cycle. Generally speaking, the menstrual cycle is usually between 25-35 days. A woman with PCOS could go months or longer without experiencing a period, so it may take several months to observe ferning.
The crystallization of saliva responds to estrogen, instead of LH, so you may get new & different information with this if you have PCOS, compared to other LH based methods. You may need to go through two or more full cycles to understand how your body is behaving in relation to this test. However, this is a good tool for people with irregular cycles, because its reusable. So you can test every day and keep track of your results, which is helpful if you have no idea of if or when you may ovulate within those 120 days. Just keep in mind, depending on how your PCOS is and in relation to your estrogen, you may or may not see ferning. If you have any questions along the way, you can contact us, but for specific questions about your individual medical needs, we recommend that you consult with your doctor.