9 Dos and Don'ts Before a PSA Test

But certain things, such as medications or an infection, could cause the number on this test to be falsely high or low. Here are nine dos and don’ts before a PSA blood test to ensure that your results are as accurate as possible.
1. Don’t: Fast Before the Test
Some blood tests, like the blood sugar test used to diagnose diabetes, require you to fast for eight hours or more to ensure the correct results. Not this one. “There’s no preparation for a PSA test,” says John L. Phillips, MD, chair and professor of urology at New York Medical College in Valhalla, New York. Not eating beforehand won’t have any effect on the results.
2. Do: Tell Your Doctor Which Medications You Take
A group of medicines called 5-alpha reductase inhibitors can affect PSA levels. These include finasteride (Propecia, Proscar) and dutasteride (Avodart), which doctors prescribe to treat benign prostatic hyperplasia (BPH) and male-pattern baldness.
A low PSA level could create a false sense of security, he says. You might think your numbers look good, or that they’re going down, when in fact they would have been high. Discuss all the medications you take with your urologist before the test. Ask if you need to come off them, and if so, for how long.
On the other end of the spectrum are medicines that increase testosterone levels. “Sometimes men will take over-the-counter libido drugs or testosterone supplements. And if they’re ‘juicing up’ in the gym or they’re taking testosterone without supervision, it’s thought to increase the PSA by increasing prostatic stimulation,” says Dr. Phillips.
3. Don’t: Go Cycling Before the Test
4. Do: Get Tested for COVID
5. Do: Take a Break From Sex
During ejaculation, the prostate contracts to propel prostatic and seminal fluid out of the penis. The contraction causes minor trauma to the prostate gland, which then releases small amounts of PSA into the bloodstream, notes Rodríguez.
It’s best to avoid sex or masturbation right before the test, but you don’t have to wait too long. “The PSA usually returns to normal within two days in almost 100 percent of people,” says Phillips. “So avoiding sex longer than two days is probably unnecessary.”
6. Do: Wait Until After Urologic Procedures
7. Do: Space Out Your Digital Rectal Exam
8. Do: Wait if You Have a Catheter
9. Do: Treat a Urinary Tract Infection
The Takeaway
- The PSA test is an important part of screening for prostate cancer. It can detect cancerous changes years before symptoms appear.
- Certain things, like infections and medications, may cause false high or low results and make the test less reliable.
- Talk to your urologist about how to prepare for your PSA test and follow their directions to help improve the accuracy of your results.
- Prostate-Specific Antigen (PSA) Test. MedlinePlus. May 19, 2025.
- Kratzer TB et al. Prostate Cancer Statistics, 2025. CA: A Cancer Journal for Clinicians. September 2, 2025.
- Hellstrom W. Ask the Experts: How Male Pattern Baldness Drugs Affect Screening Tests for Prostate Cancer. Urology Care Foundation. 2021.
- PSA Test. Cleveland Clinic. March 21, 2024.
- Symptoms of COVID-19. Centers for Disease Control and Prevention (CDC). March 10, 2025.
- Frumer M et al. Prostate-Specific Antigen Level Association with COVID-19 Infection and Vaccination. Clinical Genitourinary Cancer. May 5, 2023.
- Screening Tests for Prostate Cancer. American Cancer Society. November 22, 2023.
- Digital Rectal Exam. Cleveland Clinic. May 7, 2024.
- Urinary Catheters. MedlinePlus. January 1, 2025.
- The Pros and Cons of the PSA Test. Yorkshire Cancer Research. February 28, 2024.
- Nepal A et al. Extremely Elevated Prostate-Specific Antigen in Acute Prostatitis: A Case Report. Cureus. August 18, 2023.

Tingting Tan, MD, PhD
Medical Reviewer
Tingting Tan, MD, PhD, is a medical oncologist at City of Hope National Medical Center.
Dr. Tan's research has been published in multiple medical and scientific journals, including Oncologists, Cancer Cell, and Genes and Development.
A graduate of the Beijing Medical University, Tan holds an M.D. from Peking University Health Science Center and a Ph.D. from Rutgers University. Her training includes fellowships at the University of California San Francisco Cancer Research Institute and the Fox Chase Cancer Center at Temple University.
