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PrEP lab monitoring for telehealth programs: a practical schedule

Oct 22
6 min read
Illustration of a telehealth video visit connected to a lab scientist reviewing PrEP test samples

Telehealth has made HIV pre-exposure prophylaxis (PrEP) much easier to start. A patient can book a video visit, complete an intake form and pick up a prescription without stepping into a clinic.


What keeps a PrEP program safe over months and years is less visible: a steady rhythm of lab work. Every refill and every injection depends on recent results, so the testing schedule is really the backbone of the program.


This guide walks through what current federal guidance asks for, how the schedule changes with each PrEP option, and where remote programs tend to lose patients along the way. It's written for program operators and is educational only. It isn't medical advice, and testing decisions belong with licensed clinicians.



Why PrEP programs live or die on lab cadence


PrEP is only prescribed to people who don't have HIV, and that has to be confirmed again and again. If someone acquires HIV while on PrEP and keeps taking it, the virus can develop drug resistance. That's why the medication supply and the testing calendar are tied together.


For daily oral PrEP, the CDC's clinical guidance for PrEP says prescriptions or refill authorizations should cover no more than 90 days, until the next HIV test. In other words, a missed lab visit isn't just a data gap. It's a refill that can't safely go out.



Before the first prescription


Baseline testing sets the stage. According to the CDC guidance, the key pieces include:


  • HIV testing to confirm the patient doesn't have HIV, with the required tests depending on recent PrEP or post-exposure prophylaxis (PEP) use.

  • Kidney function, calculated as estimated creatinine clearance (eCrCl) from serum creatinine, for anyone considered for oral PrEP. Kidney assessments aren't needed for injectable cabotegravir.

  • Hepatitis B screening for everyone considered for oral PrEP, because stopping these medicines in someone with active hepatitis B can cause a rebound of the virus that damages the liver.

  • A lipid profile before starting emtricitabine/tenofovir alafenamide (F/TAF).


If HIV results are discordant or unclear, the guidance says to collect a new blood specimen for retesting and hold off on PrEP until HIV status is confirmed.



The oral PrEP schedule


Once a patient is on daily oral PrEP, the CDC guidance lays out a minimum schedule.



At least every 3 months


  • Repeat HIV antigen/antibody and HIV-1 RNA tests.

  • Test sexually active patients who have STI symptoms, and screen gay and bisexual men with certain risk factors for recurrent bacterial STIs.



At least every 6 months


  • Screen sexually active people for STIs: syphilis and gonorrhea for all PrEP users, and chlamydia for gay and bisexual men, even without symptoms.

  • Check eCrCl for patients aged 50 or older, or those whose eCrCl was below 90 mL/min when they started.



At least every 12 months


  • Check eCrCl for everyone continuing oral PrEP.

  • Monitor triglycerides, cholesterol and weight for patients on F/TAF.

  • Screen heterosexually active people for chlamydia, even without symptoms.


STI screening covers the sites that match each person's exposures, such as urine, vaginal, oral or rectal swabs, plus blood for syphilis. A program that only collects urine will miss infections at other sites.



Long-acting injectables change the calendar


Injectable PrEP shifts the work from pharmacy refills to injection visits, and testing has to keep pace.



Cabotegravir every 2 months


For cabotegravir injections, the CDC guidance calls for HIV antigen/antibody and HIV-1 RNA testing at the month 1 visit and then at least every 2 months from month 3, alongside each injection. Bacterial STI screening for gay and bisexual men is recommended at least every 4 months from month 3, and for heterosexually active people at least every 6 months from month 7.


Stopping injections needs a plan too. Cabotegravir levels fade slowly over many months, a stretch the CDC calls the "tail period." For patients who stop, the guidance recommends quarterly HIV antigen/antibody and RNA testing for 12 months.



Lenacapavir every 6 months


In June 2025, the FDA approved lenacapavir (Yeztugo) for PrEP, given as injections every 6 months after starter doses. The prescribing information says to screen for HIV before starting and before each later injection, using a test approved or cleared for diagnosing acute or primary HIV-1 infection. A negative rapid point-of-care antigen/antibody result before an injection should be confirmed with a more sensitive assay.


Twice-yearly dosing means fewer visits, but each one carries more weight. A program offering several PrEP options effectively runs several testing calendars at once, and its scheduling and ordering tools need to keep them straight.



What telehealth programs need to get right


The CDC guidance supports telehealth PrEP: screening, starts and follow-up visits can happen by phone or video. It also draws a firm line on testing. Regular HIV testing should continue, and lab-only visits for HIV and other indicated tests are strongly preferred. Oral swab HIV self-tests are generally not recommended for PrEP patients, because they may not detect recent infection in people taking PrEP medications.


That leaves remote programs with two main collection routes: sending patients to a lab or draw site, or mailing self-collection kits that go to a central laboratory. Research suggests each route has its own weak spots.


  • In the PrEP@Home pilot, a home-based system of self-collected specimens and remote monitoring was highly acceptable to participants, and more than a third said they'd be more likely to stay in PrEP care if it were available.

  • In Iowa TelePrEP, about 46% of clients chose a home kit over a lab visit. Kit users were more likely to complete anorectal swabs but less likely to complete blood tests such as creatinine, and many described trouble with finger-prick collection.

  • A Seattle study of a blood self-collection device found that 88% of 141 participants were interested in home PrEP monitoring. But only 33% of those using two devices collected enough serum for three tests.


The takeaway: home kits can improve swab completion and convenience, but blood volume is the usual bottleneck. HIV, syphilis and creatinine all come from blood, and a sample that can't run all three means a repeat collection and a delayed refill.



A practical checklist for program design


  1. Build the calendar around each regimen. Oral, every-2-month and every-6-month PrEP each need their own reminders and order sets.

  2. Tie refills and injections to results. Make the system check for a recent negative HIV result before releasing medication.

  3. Match swabs to exposure history. Ask about anatomical sites at intake and on follow-up so STI screening isn't urine-only by default.

  4. Plan for blood volume. Confirm with your laboratory which collection method and minimum volume will support every test on the panel.

  5. Have a path for unclear results. Know how a repeat specimen gets collected quickly and who on the clinical team follows up.

  6. Plan for people who stop. Keep scheduling follow-up testing after someone discontinues, especially after injectable PrEP.


For teams mapping these workflows, IHDLab's overview of PrEP and STI lab testing shows how panels and collection options fit together, and our notes for telehealth lab partners cover ordering and results delivery. Programs that want collection kits under their own brand can read more about white-label test kits.



The bottom line


PrEP works best when nobody falls off the testing calendar. Know which schedule each patient is on, collect the right specimens from the right sites, and make sure every sample can support the full panel. Do that, and a telehealth PrEP program can scale without losing the safety checks behind every prescription.


If you're mapping out a PrEP monitoring workflow, the team at IHDLab, a CLIA-certified laboratory licensed in California, New York and Maryland, is always happy to talk through panel and collection logistics.



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