Lenacapavir is a long-acting medicine that has become an important development in HIV prevention. Used as pre-exposure prophylaxis, or PrEP, lenacapavir is designed to reduce the risk of sexually acquired HIV-1 infection in people who are HIV negative and at risk of acquiring HIV through sex. In the United States, lenacapavir for HIV prevention is marketed under the brand name Yeztugo. It is administered as a subcutaneous injection twice a year, making it different from daily oral PrEP medicines. The U.S. Food and Drug Administration approved the prevention formulation in 2025 as the first twice-yearly injectable PrEP regimen.
Lenacapavir is an antiretroviral medicine that works by interfering with the HIV capsid.
The capsid is a protein shell that protects HIV genetic material and plays several roles during the viral life cycle. Lenacapavir binds to the capsid and interferes with multiple stages of HIV replication.
Lenacapavir has been used in a different formulation for HIV treatment in adults with multidrug-resistant HIV-1 infection. The prevention formulation has a separate indication for reducing the risk of sexually acquired HIV-1 in HIV-negative adults and adolescents who meet the applicable criteria.
This distinction is important because HIV treatment and HIV prevention are different uses of the medicine.
PrEP refers to medication taken by people who do not have HIV to reduce the chance of acquiring HIV.
Traditional PrEP approaches have included daily oral medicines. Lenacapavir introduces a long-acting injectable approach in which preventive medication is administered at scheduled intervals.
The U.S. indication covers HIV-negative adults and adolescents weighing at least 35 kilograms who are at risk of acquiring HIV through sex.
Before beginning lenacapavir PrEP, HIV status must be confirmed. A person with an undiagnosed HIV infection should not use lenacapavir as PrEP because incomplete antiretroviral treatment can contribute to resistance.
Lenacapavir targets the HIV capsid.
The capsid is involved in several important steps of HIV replication, including the movement of viral genetic material into host cells and the assembly of new virus particles.
By binding to the capsid, lenacapavir can interfere with multiple stages of the viral life cycle.
This mechanism differs from several other antiretroviral drug classes that target enzymes such as reverse transcriptase, integrase, or protease.
The long-acting formulation also allows the medicine to remain in the body for an extended period. This property makes twice-yearly administration possible.
Lenacapavir for HIV PrEP is administered twice per year.
The medicine is given through subcutaneous injections rather than an intravenous infusion. The initial dosing process involves oral lenacapavir tablets followed by two subcutaneous injections, according to the prescribing information.
Subsequent maintenance dosing is administered approximately every six months.
Maintaining the scheduled dosing interval is important because preventive protection depends on maintaining adequate drug levels.
Missing a scheduled injection can create a period during which protection may decline. Medical follow-up is therefore an important part of long-acting PrEP.
Lenacapavir PrEP is intended for people who are confirmed to be HIV negative and have a risk of acquiring HIV through sex.
The U.S. indication includes adults and adolescents weighing at least 35 kilograms.
A healthcare professional evaluates HIV status and other factors before PrEP begins.
Because lenacapavir remains in the body for a prolonged period, the decision to begin treatment should take into account the need for ongoing follow-up and future dosing.
Confirming HIV-negative status is an essential part of PrEP.
If a person has HIV but does not know it, using a prevention-only regimen can expose the virus to an antiretroviral medicine without providing a complete HIV treatment regimen.
Regular HIV testing is therefore incorporated into PrEP care.
Testing may involve laboratory-based HIV antigen/antibody testing and, in certain circumstances, additional testing for HIV infection.
Symptoms alone cannot reliably determine whether someone has HIV. Laboratory testing is necessary.
Clinical research has demonstrated very high protection against sexually acquired HIV among participants receiving twice-yearly lenacapavir.
The major advantage of the injectable approach is that protection does not depend on remembering a daily pill.
This can be particularly relevant for people who have difficulty maintaining daily medication routines, experience concerns about privacy, or prefer less frequent dosing.
The effectiveness of any PrEP strategy depends on correct use and adherence to the prescribed schedule.
Lenacapavir should therefore be viewed as part of an ongoing HIV prevention program rather than as a one-time injection.
Lenacapavir is designed to reduce the risk of HIV acquisition, but it does not protect against other sexually transmitted infections.
Condoms can reduce the risk of HIV and several other sexually transmitted infections when used correctly and consistently.
For this reason, safer-sex practices remain an important part of comprehensive sexual health care.
PrEP also does not prevent pregnancy.
People who need protection against pregnancy or other sexually transmitted infections may require additional preventive measures.
As with other medicines, lenacapavir can cause side effects.
Injection-site reactions are among the most commonly reported effects. These can include pain, redness, swelling, or a small lump at the injection site.
Because the medicine is injected under the skin, local reactions may persist for some time.
Other adverse effects can occur, and individual experiences vary.
A healthcare professional should be informed about persistent, severe, or concerning symptoms following treatment.
Long-acting injections can produce a different type of side-effect experience compared with daily tablets.
A person may develop tenderness, redness, swelling, or a firm area at the injection site.
These reactions are generally monitored as part of routine care.
Because lenacapavir remains in the body for a long period, it cannot simply be removed immediately if an adverse reaction occurs.
This is one reason why medication history, other medicines, allergies, and medical conditions should be reviewed before administration.
Lenacapavir can interact with certain other medicines.
Because it remains in the body for a prolonged period, these interactions can persist after the last injection.
Some medicines can alter lenacapavir concentrations, while lenacapavir can affect the concentrations of other medicines.
A complete medication list should therefore be reviewed before starting PrEP.
Prescription medicines, over-the-counter products, supplements, and recreational substances may all be relevant when evaluating potential interactions.
Stopping a long-acting medicine requires careful planning.
Lenacapavir can remain in the body for 12 months or longer after the last injection. The drug can also affect certain other medicines for an extended period.
If scheduled injections are discontinued, HIV prevention can become less reliable as drug concentrations gradually decline.
Medical advice is important when stopping PrEP so that another HIV prevention strategy can be started when appropriate.
This is particularly important because low concentrations of an antiretroviral medicine can create conditions that may contribute to resistance if HIV infection occurs.
The prevention use of lenacapavir should not be confused with the treatment formulation.
Yeztugo is indicated for HIV PrEP. Lenacapavir is also marketed under the name Sunlenca for treatment of HIV-1 infection in certain adults with multidrug-resistant HIV, but that treatment use requires combination with other HIV medicines.
PrEP is intended for people who do not have HIV.
If HIV infection is diagnosed, a complete HIV treatment regimen is required rather than continuing prevention medication alone.
Daily oral PrEP requires medication to be taken according to a regular schedule.
Lenacapavir changes the dosing pattern to twice-yearly administration.
The difference can be important for people who struggle with daily medication adherence.
Daily tablets may still be appropriate for many people because different PrEP medicines have different characteristics, costs, access requirements, side-effect profiles, and eligibility considerations.
The most suitable prevention strategy depends on individual circumstances and clinical assessment.
Long-acting prevention may address some practical barriers associated with daily medication.
A twice-yearly injection can reduce the number of medication-taking decisions required during the year.
It can also reduce concerns about storing pills or taking medication every day in circumstances where privacy is important.
Another potential advantage is that scheduled healthcare visits create regular opportunities for HIV testing and sexual-health assessment.
However, the injection schedule itself must be maintained. Long-acting treatment does not eliminate the need for follow-up.
Regular appointments are particularly important with long-acting PrEP.
Healthcare visits may include HIV testing, assessment of side effects, review of other medicines, and administration of the next injection.
Maintaining the recommended dosing interval helps ensure that preventive drug levels remain appropriate.
Missed appointments should be addressed promptly rather than simply waiting until the next routine visit.
Antiretroviral resistance occurs when HIV develops genetic changes that reduce the effectiveness of particular medicines.
This is one reason HIV testing is essential before and during PrEP.
If HIV infection occurs while drug levels are present, the treatment team may need to evaluate the situation carefully and select a complete HIV treatment regimen.
The long persistence of lenacapavir means that management after discontinuation also requires consideration of the remaining drug in the body.
Pregnancy and breastfeeding can require additional medical assessment when considering HIV prevention medicines.
The decision to use lenacapavir during pregnancy or breastfeeding should be discussed with a qualified healthcare professional who can consider current evidence, HIV exposure risk, and individual circumstances.
HIV prevention remains particularly important during pregnancy because HIV acquired during pregnancy can have consequences for both the pregnant person and the infant.
Lenacapavir is specifically intended to reduce the risk of HIV-1 acquisition.
It does not provide broad protection against sexually transmitted infections such as syphilis, gonorrhea, chlamydia, herpes, or human papillomavirus.
Sexual-health care may therefore include screening for other infections, vaccination where appropriate, condom use, and other preventive measures.
HIV prevention can involve several complementary strategies.
These may include:
Lenacapavir represents one part of this broader prevention framework.
No single prevention method addresses every form of HIV exposure or every sexually transmitted infection.
The most distinctive characteristic of lenacapavir PrEP is its long dosing interval.
Instead of taking a tablet every day, the prevention regimen is administered twice per year.
The medicine also has a different mechanism from many earlier HIV medicines because it targets the viral capsid.
The combination of a novel mechanism and long duration has made lenacapavir an important development in HIV prevention research and clinical care.
The World Health Organization has also recommended injectable lenacapavir as an additional HIV prevention choice, describing it as the first twice-yearly injectable PrEP product.
No. Lenacapavir is an antiretroviral medicine, not a vaccine.
It works by interfering with HIV replication if exposure occurs rather than training the immune system to recognize HIV in the way a traditional vaccine does.
The prevention regimen is designed around twice-yearly administration.
The medicine can remain in the body much longer than the six-month dosing interval, which is relevant when considering missed doses, discontinuation, and drug interactions.
No. It is specifically intended to reduce the risk of sexually acquired HIV-1. Additional preventive measures are needed for other infections.
PrEP is intended for people who are HIV negative. A person diagnosed with HIV requires an appropriate complete treatment regimen.
Yes. HIV testing is an essential part of PrEP care before treatment begins and during ongoing follow-up.
Long-acting HIV prevention represents a significant change in the way PrEP can be delivered.
For decades, HIV prevention strategies have included behavioral measures, condoms, testing, and oral antiretroviral medicines. Injectable lenacapavir adds another approach that requires administration only twice each year.
The broader significance of the medicine extends beyond dosing frequency. A prevention method that reduces the need for daily medication may help address adherence challenges for some populations.