Flo Digital Contraceptive Study

Conditions

• Contraception Use

Eligibility Criteria

Sex

FEMALE

Age

18 Years - N/A

Healthy Volunteers

Not accepted

Interventions

• Flo Digital Contraceptive — DEVICE
  The Flo Digital Contraceptive (FDC) is a fertility awareness-based Software as a Medical Device (SaMD) integrated within the Flo Period \& Cycles Tracker app (iOS) in 'prevent pregnancy' mode. The FDC uses a proprietary machine-learning algorithm to classify each day of the user's menstrual cycle as either 'Not fertile' (unprotected intercourse permitted) or 'Use protection' (abstinence or barrier contraception required). Classifications are generated dynamically using menstrual cycle history and overnight wrist-skin temperature measured via Apple Watch (Series 8 or later, or Ultra), synchronized daily through Apple Health, with optional urinary LH test results as a supplementary input. Participants use FDC as their sole method of contraception for up to 13 menstrual cycles or 18 months from device activation, whichever occurs first.

Study Details

The goal of this clinical trial is to learn if the Flo Digital Contraceptive (FDC) app can effectively prevent unintended pregnancy in women aged 18 years and older residing in the United States. The main questions it aims to answer are: What is the rate of unintended pregnancy in women aged 18-35 years using FDC as their sole method of contraception under typical-use conditions, measured using the Pearl Index? What is the cumulative probability of unintended pregnancy over 13 menstrual cycles for all participants, including those with regular and irregular cycles? Participants will: Use the Flo Digital Contraceptive app in 'prevent pregnancy' mode as their primary method of contraception for up to 13 menstrual cycles or 18 months, whichever comes first Wear an Apple Watch (Series 8 or later, or Ultra) while sleeping to collect nightly wrist temperature data, which the app uses to detect ovulation Log menstrual cycles, sexual activity, and any use of emergency contraception directly in the Flo app Complete monthly electronic surveys (ePROs) administered by the study team covering pregnancy status, adherence, safety, and experience Complete a baseline demographic survey at enrollment and an exit survey at the end of participation

Key Dates

Start date

Apr 22, 2026

Status verified

Jun 2026

Primary completion

Jan 10, 2028

Completion

Jan 10, 2028

Study Design

Enrollment

3,800 participants (estimated)

Allocation

NA

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Arms

• Experimental: Single Arm Device Intervention
  Users exposed to the Flo Digital Contraceptive

Primary Outcome Measure

Typical-Use Pearl Index in Women Aged 18-35 Years with Regular Menstrual Cycles [ Time Frame: Up to 13 menstrual cycles or 18 months from FDC activation, whichever occurs first. ]

Central Contacts

• Collin Anderson, MPH
  833-930-8220
  [email protected]
• Keith Boland
  (833) 930-8220

Locations (1)

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