Cycle Tracking Wearables

Manufacturer information and editorial guidance. Ninaix has not tested the devices. Historical source dates are retained.

Wearables can show temperature and cycle trends, but features, eligibility and intended use differ. A cycle insight is not automatically a contraceptive method.

Temperature trends

Oura says Cycle Insights uses temperature deviations and period logging. It is available on supported rings with active membership. Check current eligibility in the Oura documentation.

Contraception is a separate claim

Oura states that its own fertile window estimates should not be used as birth control. Natural Cycles states that it is cleared by the FDA as a Class II medical device for birth control, and it is a separate product with its own instructions and subscription.

Choosing a setup

Compare what a device measures, what the app does with the data and whether the feature is intended for cycle awareness or contraception. Do not infer contraceptive effectiveness from temperature tracking alone.

Sources. Oura Cycle Insights, page last updated October 14, 2026 Oura Fertile Window manual version 2.1 or later, page updated June 3, 2026; read October 27, 2026 Natural Cycles certifications, read October 27, 2026 FDA De Novo record DEN170052, decision August 10, 2018; read October 27, 2026