Text messaging versus a smartphone app to help people take PrEP

Comparing Mobile Health Strategies to Improve Pre-exposure Prophylaxis Use (PrEP) for HIV Prevention

Not applicable Interventional Public Health Foundation Enterprises, Inc. · NCT04855773

This project will see if weekly text messages or a smartphone app better help cisgender and transgender men who have sex with men and transgender women take daily PrEP as prescribed.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment300 (estimated)
Ages15 Years and up
SexAll
SponsorPublic Health Foundation Enterprises, Inc. Academic / other
Locations4 sites (San Francisco, California and 3 other locations)
Trial IDNCT04855773 on ClinicalTrials.gov

What this trial studies

This is a clinic-based, multi-site, randomized two-arm trial comparing an interactive SMS program (PrEPmate) to a smartphone app (Dot Diary) to support PrEP adherence and continuation. All participants receive PrEP per standard of care at participating clinics and are followed for about 12 months. PrEPmate uses bidirectional weekly check-ins, daily pill reminders, and links to online PrEP education; Dot Diary provides a digital pill and sexual diary, reminders, reward badges, and real-time feedback on protection. Clinic staff will also be interviewed about implementation challenges and their experiences working with patients using these technologies.

Who should consider this trial

Good fit: Ideal participants are cisgender men, transgender men, or transgender women aged 15 or older who have sex with men or people assigned male at birth, own an iOS or Android phone, speak English or Spanish, and are newly on PrEP or at increased risk of stopping PrEP.

Not a fit: People without a smartphone or reliable texting/internet access, those outside the eligible gender/sex groups, or individuals already consistently adherent to PrEP may not benefit from these interventions.

Why it matters

Potential benefit: If successful, the better-performing intervention could help more people stay on PrEP and lower HIV risk by improving daily medication adherence.

How similar studies have performed: Prior SMS and other mHealth interventions for medication adherence have shown modest improvements, while app-based tools for PrEP adherence are newer and less well-established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Self-identifies as a cisgender man, transgender man (assigned female at birth, trans-masculine spectrum), or transgender woman (assigned male sex at birth, trans-feminine spectrum)
* Report sex with a cisgender man or transgender woman or any individual assigned male sex at birth in the past 12 months
* Age 15 years or older
* Willing and able to provide written informed consent
* Owns an iOS or Android mobile phone and able to access the internet and send and receive text messages
* Able to understand, read, and speak English or Spanish
* Newly initiated PrEP or currently on PrEP and at risk for PrEP discontinuation based on at least one of the following:

  * Initiated PrEP within the past 6 months, or
  * Has any of the following risk factors for PrEP discontinuation: missed clinic visits; age \< 30; African-American or Latino; transgender gender identity; or self-reported illicit substance use

Exclusion Criteria:

* Currently enrolled in another PrEP intervention study
* Unable to complete 12 month study participation
* Any medical, psychiatric, or social condition or other responsibilities that, in the judgment of the investigator, would make participation in the study unsafe, complicate interpretation of study outcome data, or otherwise interfere with achieving the study objectives.

Where this trial is running

San Francisco, California and 3 other locations

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions HIV InfectionsSexually Transmitted DiseasesPre-exposure ProphylaxisHIV PreventionMobile healthMedication adherence
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.