Lenacapavir is used in adults with other antiviral drugs to treat HIV, the virus that can cause acquired immunodeficiency syndrome (AIDS). Lenacapavir is not a cure for HIV or AIDS.

Lenacapavir is given after several other HIV medications did not work, have stopped working or could not be tolerated.

Lenacapavir may also be used for purposes not listed in this medication guide.

Tell your doctor about all your other medicines. Some drugs should not be used with lenacapavir.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

The starting dose of lenacapavir is usually given as tablets and injections, followed by maintenance injections every six months (26 weeks). Your doctor will determine the right treatment for you.

You may take lenacapavir with or without food.

A healthcare provider will give you this injection under the skin in the abdomen.

Lenacapavir may affect other medicines for up to 9 months after your last injection.

Store at room temperature in the original container, away from moisture and heat.

There may be other reasons you should not use lenacapavir in combination with certain medicines, such as efavirenz, nevirapine, rifabutin, rifampin, rifapentine, carbamazepine, oxcarbazepine, phenytoin, primidone, dexamethasone, prednisone, St. John's wort, phenobarbital or other barbiturate medicine.

Tell your doctor if you have ever had:

• an autoimmune disorder such as Graves' disease, polymyositis, or Guillain-Barré syndrome.

To prevent HIV in a newborn baby, use all medications to control your infection during pregnancy. Your name may be listed on an antiviral pregnancy registry.

It is not known if lenacapavir will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Women with HIV should not breastfeed. The virus can pass to your baby in your breast milk.

Call your doctor for instructions if you miss an appointment for your lenacapavir injection.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Lenacapavir can affect your immune system (even weeks or months after you've used this medicine). Tell your doctor if you have:

• signs of a new infection--fever, night sweats, swollen glands, cold sores, cough, wheezing, diarrhea, weight loss;

• trouble speaking or swallowing, problems with balance or eye movement, weakness or prickly feeling; or

• swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence.

Common side effects of Sunlenca may include:

• bruising, swelling, warmth, redness, oozing, or bleeding where an injection was given; or

• nausea.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your current medicines. Many drugs can affect lenacapavir, especially:

• phenobarbital or other barbiturate medicine;

• St. John's wort;

• an antibiotic--rifabutin, rifampin, rifapentine;

• cancer medicine--apalutamide, enzalutamide, mitotane;

• HIV or AIDS medicine--efavirenz, nevirapine;

• seizure medicine--carbamazepine, oxcarbazepine, phenytoin, primidone; or

• steroid medicine--dexamethasone, prednisone.

This list is not complete and many other drugs may affect lenacapavir. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.