Medications and Habits: What to Avoid During PrEP?

October 9, 2025 •

4 min read

PrEP (pre-exposure prophylaxis) is over 99% effective at preventing HIV when taken consistently, but its effectiveness can be compromised by certain medications, supplements, or health conditions. For those considering or taking this preventative treatment, knowing what to avoid during PrEP is crucial for both its efficacy and overall health.

Quick Summary

Taking PrEP requires careful consideration of other medications, particularly NSAIDs and some hepatitis C drugs, due to potential interactions affecting kidney function. Health providers must also screen for pre-existing conditions like HIV infection and kidney impairment. Adherence is paramount, and lifestyle factors like substance use must be managed to prevent missed doses.

Key Points

HIV-Positive Status: PrEP is for HIV-negative individuals only; testing is required before starting and regularly thereafter.
Regular NSAID Use: Chronic use of NSAIDs like ibuprofen with tenofovir (TDF) PrEP can increase kidney health risks.
Kidney Impairment: Pre-existing or severe kidney problems may contraindicate oral PrEP, necessitating careful evaluation.
St. John's Wort: This herbal supplement can reduce the effectiveness of TAF-based PrEP (Descovy) and should be avoided.
Adherence Killers: Excessive alcohol or recreational drug use can cause you to miss doses, significantly lowering PrEP's protective power.
Full Medication Disclosure: Always inform your provider of all medications, including supplements, as they may affect PrEP efficacy or kidney test results.

Navigating PrEP successfully involves more than just remembering to take a pill. A crucial part of the process is understanding potential interactions and contraindications that could impact the medication's safety and effectiveness. From common over-the-counter pain relievers to certain herbal supplements, several factors require careful consideration and discussion with your healthcare provider.

Contraindications: When PrEP is Not an Option

The most critical contraindication for starting PrEP is a confirmed HIV-positive status. PrEP medications are not a treatment for existing HIV infection, and using them in someone who is already HIV-positive could lead to the development of drug-resistant strains of the virus, making future HIV treatment more difficult. For this reason, a confirmed HIV-negative test is required before starting PrEP, and regular testing is necessary while on the medication.

Other significant contraindications relate to kidney health. Since the most common oral PrEP drugs are processed and eliminated by the kidneys, pre-existing or severe kidney impairment can be a barrier to starting treatment.

For TDF/FTC (Truvada and generics): The CDC recommends against starting this regimen in individuals with a confirmed creatinine clearance (CrCl) less than 60 mL/min.
For TAF/FTC (Descovy): The threshold is less than 30 mL/min CrCl.

Medication and Supplement Interactions to Watch For

Several medications and supplements can interact with PrEP, potentially affecting its efficacy or increasing the risk of side effects, particularly concerning kidney function. Always inform your doctor or pharmacist of any other medications or supplements you are taking.

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

Regular, long-term use of NSAIDs like ibuprofen, naproxen, and diclofenac should be avoided while on PrEP, especially for those taking tenofovir disoproxil fumarate (TDF)-based regimens (Truvada). Both TDF and NSAIDs can affect kidney function, and the combination can increase the risk of kidney problems. Occasional use is generally considered safe for healthy individuals, but frequent use should be monitored closely by a healthcare provider. For pain and fever relief, acetaminophen is often the preferred and safer alternative.

Hepatitis C Medications

Certain medications used to treat Hepatitis C, such as sofosbuvir and ledipasvir, can interact with PrEP. If you have Hepatitis C and are considering PrEP, your doctor will need to manage your treatment plan carefully to avoid complications. Always disclose your full medical history and all medications to your provider.

Herbal Remedies and Supplements

Herbal products are not regulated in the same way as prescription medications, and their safety when combined with PrEP cannot be guaranteed.

St. John's Wort: This herbal supplement, sometimes used for depression, should be avoided by those taking TAF-based PrEP (Descovy). It can significantly decrease the concentration of PrEP drugs in the body, reducing their effectiveness.
Creatine: While not a direct interaction, creatine supplements can artificially elevate creatinine levels in the blood, which is the main marker for kidney function. This can cause a false positive result during kidney monitoring, potentially affecting a doctor's decision on whether you can continue PrEP. It is crucial to inform your doctor if you use creatine supplements.

Other Prescription Drugs

Some other medications require caution and careful monitoring when taken with PrEP. These include:

Aminoglycosides (for bacterial infections)
Amphotericin B (for fungal infections)
Foscarnet (for viral infections)
Certain antifungals and anti-seizure medications (especially with Descovy)

Lifestyle Habits and PrEP Adherence

While PrEP has no known direct interactions with alcohol, recreational drugs, or certain lifestyle habits, these factors can indirectly impact your ability to take the medication consistently. Adherence—taking PrEP exactly as prescribed—is the most critical factor for its effectiveness. A missed dose can significantly lower your protection against HIV.

Alcohol: Excessive alcohol consumption can impair judgment and disrupt your routine, leading to forgotten doses. Some people may also experience heightened dizziness or other mild side effects when drinking heavily on PrEP.
Recreational Drugs: Similar to alcohol, recreational drug use can lead to inconsistent medication use and increased engagement in risky behaviors, undermining PrEP's protection.

Understanding the Differences Between PrEP Medications

Different oral PrEP formulations come with distinct considerations regarding what to avoid. The following table provides a quick overview of potential risks and interactions associated with the two most common options.


Feature	TDF/FTC (Truvada & Generics)	TAF/FTC (Descovy)
Tenofovir Formulation	Tenofovir Disoproxil Fumarate (TDF)	Tenofovir Alafenamide (TAF)
Primary Kidney Risk	Moderate; Regular monitoring required, especially with NSAID use.	Lower; Less impact on kidney health, but still monitored.
Kidney Contraindication	Not for individuals with CrCl < 60 mL/min.	Not for individuals with CrCl < 30 mL/min.
Bone Health Impact	Small but measurable decrease in bone mineral density; typically reversible.	Less impact on bone mineral density.
Drug Interactions	Caution with NSAIDs, Hepatitis C drugs.	Avoid St. John's Wort and some seizure/antifungal drugs.
Approved For	Adults and adolescents at risk via sexual activity or injection drug use.	Cisgender men and transgender women at risk via receptive anal sex; NOT for receptive vaginal sex.

A Note on Pregnancy and Hormonal Therapy

For individuals who are or may become pregnant, TDF/FTC-based PrEP is generally considered safe, but discussion with a healthcare provider is essential. Hormone-based birth control methods are not known to have adverse interactions with PrEP, and gender-affirming hormone replacement therapy (HRT) can be used safely with PrEP, though it might slightly lower PrEP levels.

Conclusion: Prioritize Open Communication

PrEP is a highly effective tool for preventing HIV when used correctly. The most important step to ensure its safety and efficacy is to maintain open, honest communication with your healthcare provider. Before starting PrEP, and throughout your treatment, disclose all medications, supplements, and lifestyle habits. Regular check-ups, which include HIV and kidney function testing, are crucial for staying healthy while on PrEP. Never make assumptions about what is safe to take alongside your PrEP regimen; always consult a medical professional. For reliable resources, the CDC's HIV Nexus page offers comprehensive clinical guidance on PrEP, including considerations for co-administered medications and specific populations.

Frequently Asked Questions

You should avoid regular or long-term use of NSAIDs like ibuprofen, naproxen, or diclofenac, especially if you are on a TDF-based PrEP regimen. These medications can affect kidney function, and the combination increases the risk of side effects. Occasional use is generally fine, but for frequent pain relief, acetaminophen is often a safer choice.

While there are no known direct drug-drug interactions with the common oral PrEP pills, the main risk is missed doses. Recreational drug use can lead to inconsistent medication habits and poor adherence, which is the most common reason for PrEP failure.

There are no known direct interactions between alcohol and oral PrEP medications. The biggest concern is that heavy drinking can lead to lapses in judgment and missed doses. As PrEP requires consistent daily use to be maximally effective, it's important to manage alcohol consumption to ensure you don't forget to take your pill.

You should avoid taking St. John's Wort, as it can reduce the effectiveness of TAF-based PrEP (Descovy). Inform your doctor if you take creatine, as it can interfere with kidney function test results, which are regularly monitored while on PrEP.

It depends on the type of hepatitis and the medications used to treat it. Certain Hepatitis C drugs are known to interact with PrEP. You must have an open conversation with your healthcare provider, who will manage your treatment plan carefully to ensure safety.

Yes, you must have a confirmed HIV-negative test before starting PrEP, and it must be done again at regular intervals while on the medication. Taking PrEP while HIV-positive is dangerous and can cause drug resistance.

Oral PrEP requires careful consideration if you have kidney problems. Your kidney function (measured by creatinine clearance or CrCl) must be within a certain range to safely take oral PrEP. If you have severe kidney impairment, your doctor may recommend an alternative HIV prevention strategy, such as injectable PrEP.