In simple terms: a urine test kit that detects the luteinising hormone (LH) surge to predict ovulation.
Why it matters for PCOS
An OPK detects the rise of luteinising hormone in urine, the hormone that spikes sharply just before an egg is released. When the test line turns positive, it signals that ovulation is likely within about 24 to 36 hours, helping you identify the fertile window. In PCOS, LH is often persistently high, so an OPK can give false positives or several positives that do not actually match a real ovulation.
For this reason, OPK results should be read alongside other signs such as your cycle pattern, or with doctor monitoring. An OPK only predicts upcoming ovulation; it does not confirm that an egg was actually released.
This glossary is education, not diagnosis. For your own situation, ask a doctor or pharmacist.