Descovy can be used for preexposure prophylaxis (PrEP) in certain people. It is effective for PrEP after at least 7 days of daily use.

Descovy is approved* for PrEP for people who do not have HIV but are at risk of contracting the virus. Specifically, it is used in adults and adolescents who weigh at least 35 kilograms (kg). Adolescents are children ages 12 years and older.

Descovy is not approved for PrEP in people at risk of contracting HIV through vaginal intercourse.

You must be HIV-negative before starting Descovy for PrEP. You also need to undergo HIV testing before taking this medication.

This article examines the effectiveness of Descovy for PrEP and how long it may take for the drug to start working. For more general information, check out this Descovy for PrEP article.

* Descovy is also approved to treat HIV, in combination with other medications, in adults and certain children.

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Descovy is one of two oral tablets approved for PrEP, with the other being Truvada.

According to the Centers for Disease Control and Prevention (CDC)Trusted Source, the time it takes for oral PrEP tablets to provide maximum protection against HIV from sex is as follows:

  • in cases of receptive anal sex, around 7 days of daily use
  • in cases of receptive vaginal sex and injection drug use, 21 days of daily use, but Descovy is not indicated for these uses

Descovy may be used as a long-term treatment. Talk with your doctor to find out how long you may need to take this medication for PrEP.

Note: If you have had exposure to HIV, you will need to take postexposure prophylaxis (PEP). You will need to take PEP within 72 hours, or 3 days, of possible HIV exposure.

Stopping Descovy

Do not stop taking Descovy without talking with your doctor first. After you take your last dose, the medication may remain in your system for a few days.

Oral PrEP is around 99% effectiveTrusted Source if you take the medication daily or at least 4 times a week.

It is important that you follow the recommended dosing schedule to make sure Descovy is as effective as possible. Missing doses may increase the risk of contracting HIV.

Descovy may reach its maximum protection at around 7 daysTrusted Source of taking the medication each day. Before this time, it is unclear how effective the medication is at protecting against HIV.

If you do not take Descovy as your doctor prescribes, there may not be enoughTrusted Source of the drug in the bloodstream to prevent HIV from replicating in the body and causing HIV infection. Taking Descovy exactly as prescribed helps protect against developing HIV.

Descovy has approval for preexposure prophylaxis (PrEP). If you take the medication as a doctor prescribes, it may be 99% effective against HIV.

You will need to take Descovy daily for at least 7 days for the drug to provide maximum protection against HIV. Before 7 days of daily use, it is not clear how effective the medication will be at protecting against HIV.

You will need to talk with your doctor to find out how long you may need to take Descovy.