If you’re at a high risk of HIV but haven’t been diagnosed with it, pre-exposure prophylaxis (PrEP) could be a suitable consideration. Consistently taking this medication daily significantly lowers the likelihood of acquiring HIV.

Pre-exposure prophylaxis (PrEP) is a daily medication aimed at preventing the onset of HIV infections. It is designed for individuals who do not have HIV but are at an elevated risk of acquiring the virus.

PrEP works by reducing the risk of HIV transmission, safeguarding both you and your partners from potential infection. It is not intended for individuals who are already living with HIV.

Presently, there are two specific antiviral medications approved by the FDA for PrEP. When taken consistently, these medications demonstrate high efficacy in preventing HIV infections.

Continue reading to delve deeper into PrEP medications and their role in reducing the risk of HIV transmission.

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What is PrEP? | Types | Candidates | Effectiveness | Safety | Bottom line

How does PrEP work in preventing HIV?

Pre-Exposure Prophylaxis (PrEP) functions through the utilization of drugs classified under nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), which are a type of antiviral medication. These drugs act by impeding the replication of the HIV virus within the body.

Prior to commencing PrEP treatment, and at intervals of at least every three months throughout its duration, individuals are required to undergo HIV testing to confirm a negative status.

In instances where individuals have encountered potential exposure to HIV or exhibit symptoms indicative of an acute infection, it is imperative to await confirmation of a negative test result before resuming PrEP medication.

The necessity of awaiting a negative test result is paramount due to the inability of PrEP to effectively combat HIV infection independently. Moreover, there exists a risk of developing drug resistance if PrEP is administered during an active HIV infection.

Integral to the PrEP regimen is prevention counseling, which involves comprehensive discussions with healthcare professionals to:

- Gain a deeper understanding of the individual's risk factors for HIV acquisition.
- Explore various preventive measures available.
- Assess the potential benefits of integrating PrEP into the daily routine.

The duration of PrEP usage is contingent upon individual health considerations. It is advisable to engage in dialogue with healthcare providers to evaluate personal health circumstances and determine the optimal duration for PrEP utilization.

What are the different types of PrEP?

There are two FDA-approved medications for PrEP: Truvada and Descovy. Truvada

Truvada comprises the active components emtricitabine and tenofovir disoproxil fumarate. It is obtainable in both branded and generic formulations.

Available in multiple potencies, Truvada is prescribed for the treatment of HIV as well as for PrEP.

Administered in tablet form, it is taken once daily by adults and adolescents weighing at least 35 kilograms (approximately 77 pounds). Truvada is authorized for use in both male and female populations. Descovy

Descovy, like Truvada, is a once-daily tablet. It contains emtricitabine and tenofovir alafenamide as its active ingredients.

Suitable for adults and adolescents weighing at least 35 kilograms (77 pounds), Descovy has not been endorsed for use in females at higher risk of HIV acquisition through vaginal intercourse, as its effectiveness has not been adequately assessed in this demographic.

Who might be a good candidate for PrEP?

As per the Centers for Disease Control and Prevention (CDC), approximately 1.2 million individuals in the United States were diagnosed with HIV in 2018, with 1 in 7 unaware of their HIV-positive status.

Individuals who could benefit from PrEP therapy include those who have engaged in anal or vaginal intercourse within the past 6 months and individuals who:

- Have a sexual partner diagnosed with HIV, either with a detectable viral load or with an unknown viral load.
- Have inconsistently used condoms during sexual activity.
- Have contracted a sexually transmitted infection (STI) within the previous 6 months.

Additionally, PrEP is recommended for individuals who inject drugs and:

- Share needles (syringes).
- Have an injection partner who has tested positive for HIV.

For individuals who have undergone post-exposure prophylaxis (PEP) on multiple occasions and continue to face heightened risks of HIV acquisition, consulting a healthcare professional about initiating PrEP is advisable.

Pros and cons of HIV PrEP therapy

Several factors merit consideration when contemplating the initiation of a new medication. Here are some key aspects to ponder when assessing whether PrEP aligns with your needs:


- The medications demonstrate high efficacy in preventing HIV transmission when taken consistently.
- They offer protection against HIV transmission for both you and your partner.
- PrEP involves the convenience of a once-daily pill regimen.
- It affords discreet and individualized control over prevention, particularly beneficial for individuals at elevated risk of HIV acquisition.
- PrEP presents an option for serodiscordant couples (where one partner is HIV-positive and the other is not) who desire to conceive.


- Brand-name formulations of Truvada and Descovy can be costly, particularly without insurance coverage.
- Adherence to a daily dosing schedule is essential.
- Regular HIV testing is required, typically every 3 months.
- These medications may entail side effects (refer to the safety section below).
- PrEP may not be suitable for individuals with severe kidney impairment or a history of hepatitis B.

Does PrEP for HIV work?

When adhered to according to a doctor’s prescription, PrEP is highly efficacious in averting HIV transmission.

As per data from the Centers for Disease Control and Prevention (CDC), these medications, when consistently taken, can reduce the risk of acquiring HIV through sexual intercourse by approximately 99 percent. Moreover, among individuals who engage in injection drug use, PrEP reduces the risk by about 74 percent.

It’s important to note that the protective effects of these medications are not immediate. For optimal safeguarding against HIV transmission during receptive anal intercourse, it is necessary to adhere to daily PrEP for a minimum of 7 days. Similarly, for individuals engaging in injection drug use or receptive vaginal intercourse, maximum protection is typically achieved after approximately 21 days of consistent daily PrEP usage.

It should be emphasized that the effectiveness of Descovy specifically among females who engage in receptive vaginal intercourse has not been definitively established.

Is it safe to take PrEP for HIV?

Truvada and Descovy, the two primary medications used for PrEP, are generally safe, but some individuals may experience side effects, some of which may be severe.

Before initiating PrEP with Descovy or Truvada, it’s crucial to discuss any existing health conditions with a healthcare professional, as well as the potential side effects and benefits of PrEP. Individuals with significant kidney conditions may find these medications unsafe for use.

Moreover, if an individual has had a history of hepatitis B infection, it’s essential to inform their healthcare provider. Discontinuing Truvada or Descovy may exacerbate a hepatitis B infection, and medical supervision is necessary to monitor liver function and manage any flare-ups of hepatitis B.

It is imperative not to take PrEP medications if one is already living with HIV, as this could lead to the development of drug resistance against the virus.

Before initiating PrEP, individuals will undergo blood testing, and testing will be repeated at least every three months throughout the duration of PrEP usage.

Possible side effects

Common side effects associated with both Truvada and Descovy may include:

- Diarrhea
- Fatigue (tiredness)
- Headache
- Nausea

Although rare, serious side effects of both medications may comprise:

- Rash (indicative of an allergic reaction)
- Liver and kidney complications
- Aggravation of hepatitis B infection
- Lactic acidosis (excessive lactic acid accumulation in the bloodstream)

These listed side effects are not exhaustive, and individuals are encouraged to consult a healthcare professional or pharmacist for comprehensive information regarding these medications, including potential interactions with other prescribed or over-the-counter drugs.

In the event of an allergic reaction or any other severe side effects attributed to PrEP medications, it is imperative to seek immediate medical attention by calling 911 or visiting an emergency medical facility.

Getting the conversation started about HIV prevention and protection with a healthcare professional is crucial if you believe you may be at higher risk of contracting HIV. Here are some steps you can take to initiate a meaningful discussion:

- Educate yourself about the risk factors and prevention methods associated with HIV from reliable sources such as the CDC.
- Prepare a list of questions you'd like to discuss with a counselor or healthcare provider.
- Be open and transparent about your concerns regarding HIV and your overall health.
- Inquire about where you can access regular HIV testing services.
- Ask about the availability of PrEP medications in your locality.
- If you lack insurance coverage, inquire whether your state health department offers free or subsidized access to PrEP.
- Explore strategies for communicating with sexual partners about HIV prevention and protection.

Initiating such a conversation with a healthcare professional can provide valuable insights and guidance tailored to your specific circumstances and needs.

The bottom line

The bottom line is, if you believe you may be at risk of contracting HIV, it’s essential to prioritize regular testing and engage in discussions with a counselor or healthcare professional regarding preventive measures.

Incorporating Pre-Exposure Prophylaxis (PrEP) into your prevention strategy can significantly reduce the likelihood of HIV transmission. PrEP is a highly effective medication regimen designed to lower your risk of acquiring HIV and prevent transmission to your sexual partners.

To take proactive steps towards HIV prevention and safeguarding your health, consider speaking with a healthcare professional or scheduling an appointment at a clinic that offers counseling on HIV prevention and related healthcare services.

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What is PrEP? | Types | Candidates | Effectiveness | Safety | Bottom line