Clue

Clue is a science-based period and cycle tracking app developed with researchers and endorsed by reproductive health professionals worldwide. For women with PCOS who are tired of apps that assume a perfectly regular 28-day cycle, Clue stands out for its rigorous, non-judgmental approach to tracking irregular menstruation.

Available free on iOS and Android, Clue lets you track your period start and end dates, flow intensity, PCOS-related symptoms (including cramps, acne, bloating, mood changes, and more), sex drive, and sexual activity. Unlike apps that project future cycles based on averages, Clue uses your actual historical data to generate predictions — making it far more useful for the irregular cycles common in PCOS.

Clue is backed by a scientific advisory board and has partnered with universities to study menstrual health, giving its feature set a research-informed foundation. It is one of the few period tracking apps that explicitly avoids gender-coded design and welcomes all people who menstruate.

For PCOS women who want a no-frills, data-driven cycle tracker grounded in real science, Clue is one of the most trusted options available. Its clean interface, symptom depth, and scientific credibility make it a top choice for tracking irregular PCOS cycles.