Houston Health Department

Pre-Exposure Prophylaxis (PrEP)


I take PrEP daily. I am here. I exist. I matter. houstonIamLife.com

What is PrEP?

PrEP is short for pre-exposure prophylaxis. Two medications have been approved for use as PrEP by the FDA: Truvada® and Descovy®. Both medications are a pill taken once daily to reduce the risk of HIV infection from sexual contact or injection drug use. PrEP oral medication is only prescribed to individuals confirmed to be HIV negative prior to initiation of use.

Truvada® can be prescribed for both men and women. Descovy® excludes people who engage in receptive vaginal sex. PrEP is also approved for adolescents who test negative for HIV, who weigh at least 75 pounds (35 kg), and are vulnerable to acquiring HIV from sex or injection drug use. When taken as prescribed, the risk of HIV infection from sex is reduced by more than 90%.


Find a PrEP provider near you


The Houston Health Department offers PrEP and nPEP services at our four health centers.


Should I take PrEP?

We recommend taking PrEP if you are HIV negative and:

You have had anal or vaginal sex in the past 6 months and:

  • have a sex partner living with HIV whose viral load is unknown or detectable
  • do not use condoms consistently
  • have been diagnosed with a sexually transmitted infection (STI) in the past 6 months. 

You inject drugs and:

  • have an injection partner living with HIV, or
  • share needles, syringes, or other equipment to inject drugs.

You have used multiple courses of non-occupational post-exposure prophylaxis (nPEP).

Truvada® and Descovy® should not be prescribed to individuals who are living with HIV; display renal insufficiency; and/or indicate that they are not ready to adhere to a regimen of oral PrEP medication taken daily with periodic lab work and tests.

Is PrEP safe?

Yes. Minor side effects like nausea, diarrhea, headache, fatigue, and abdominal pain may occur in some people. Side effects are typically not serious and subside within a month. When taking Truvada®, some people may experience more serious side effects including loss of bone density (1 in 100), or kidney issues (1 in 200). If you are taking PrEP, tell your health care provider about any side effects that are severe, or do not go away within a month.

Severe acute exacerbation of hepatitis B have been reported in patients infected with hepatitis B virus (HBV) who discontinue PrEP medication abruptly. If you are positive for hepatitis B, please consult your physician before initiation or discontinuing medication.

Does PrEP really work?

Yes! PreP is highly effective at preventing HIV infection when taken daily as directed. Studies have shown that PreP reduces the risk of getting HIV from sex by more than 90% and from injection drug use by at least 74% when used consistently. ADHERENCE IS KEY, you must be willing and able to follow a regimen of oral Truvada® or Descovy® taken once daily. In addition, you will need to schedule provider visits every 3 months for lab work, prescription refills and HIV and STI testing.

Remember, PreP protects you against HIV, it does not protect you against other sexually transmitted infections (STIs) or pregnancy. Adding other prevention methods, such as condom use, along with PrEP can significantly reduce your risk of getting HIV.

How much to PrEP cost?

Insured or not, PrEP could cost as little as $0.

Many insurance plans, including Medicaid, cover PrEP. Assistance programs are also available if you are uninsured or if your co-pay or deductible is too high.

Ready, Set, PrEP provides PrEP at no cost for people without prescription drug coverage.

Manufacturer assistance programs make PrEP medication available at no cost if you do not have insurance and may cover up to $7,200 in co-pays per year with no monthly limit if you are insured.

The Patient Advocate Foundation Co-Pay Relief Program may cover up to $7,500 in co-pays per year (depending on income).

I am ready to PrEPARE myself against HIV

If you think PrEP may be right for you, talk to a health care provider, only a health care provider can prescribe PrEP. Before initiating PrEP, you must take an HIV test, you must be HIV negative to start PrEP. Talk to your provider about telehealth services for follow-up visits.

Can I take PrEP if I think I was exposed to HIV?

NO. Exposure to HIV is a medical Emergency. If you think you were exposed to HIV as a result of a high-risk event, such as a condom break, needle sharing during injection drug use or sexual assault, another medication is available, nPEP.

What is nPEP?

Non-occupational Post-exposure Prophylaxis (nPEP) is medicine that can prevent HIV infection after you are exposed. Do not delay, nPEP must be started withing 72 hours (3 days) of exposure to reduce the chance of becoming infected.

How do you know if you need nPEP?  

  • Are you a victim of rape or sexual assault?
  • Did you have unprotected sex (vaginal or anal) with someone who you know is HIV positive or someone whose HIV status you don’t know? (Unprotected means that a condom was not used, or that the condom broke or slipped off during sex.)
  • Did you share needles (for drugs, hormones, or tattoos) or other drug injection equipment with someone who is living with HIV or whose HIV status is unknown?

If you answered yes to any of these questions, go to a hospital emergency department right away or one of the Houston Health Department health centers.

Learn more about nPEP.


The Houston Health Department offers PrEP and nPEP services at our four health centers.