Marylebone Parameters
Free Prostate-Specific Antigen (fPSA)
The Free Prostate-Specific Antigen (fPSA) blood test measures the amount of free, unbound PSA circulating in the blood. PSA is a protein produced by the prostate gland, and measuring different forms of PSA can provide more detailed information about prostate health. The fPSA test is often used alongside total PSA to improve the assessment of prostate-related conditions. PSA exists in the blood in two main forms: bound to proteins and free (unbound). The proportion of free PSA compared with total PSA can help clinicians better understand the cause of a raised PSA result and guide decisions about further investigation.
What's included
Note: the live page displays 'Code: FPS' — using MLFPS per your master list.
- Free Prostate-Specific Antigen (fPSA)
What is Free PSA and why is it important?
Prostate-Specific Antigen is produced by normal prostate tissue as well as by benign and malignant prostate cells. Free PSA refers to the portion of PSA that is not bound to blood proteins. Measuring free PSA provides additional context when total PSA levels are borderline or moderately raised.
In general terms, a lower percentage of free PSA relative to total PSA may be associated with a higher likelihood of prostate cancer, while a higher percentage of free PSA is more often seen in benign conditions such as benign prostatic hyperplasia (BPH). It is important to note that this test does not diagnose cancer but helps refine risk assessment.
Why might I need a Free PSA test?
A Free PSA test may be recommended if your total PSA level is raised or borderline and further clarification is needed. It can help reduce unnecessary anxiety and guide decisions about whether additional investigations may be appropriate.
The test may also be used when monitoring prostate health over time, particularly in men with urinary symptoms, a family history of prostate disease, or previous PSA abnormalities.
What do the results mean?
Results are usually reported as a percentage of free PSA compared with total PSA. A lower percentage may suggest a higher likelihood of prostate cancer, while a higher percentage is more suggestive of benign conditions.
Results must always be interpreted alongside total PSA, age, prostate size, symptoms, and medical history. Your healthcare professional will explain what your result means for you and whether further testing is advised.
How is the test performed?
The Free PSA test is performed using a simple blood sample collected during a short appointment. The procedure is routine, and our clinical team will ensure you are comfortable throughout.
Do I need to prepare the test?
No fasting is required for this test. However, you may be advised to avoid ejaculation and vigorous exercise for 24–48 hours before testing, as these can temporarily affect PSA levels.
Why Choose Marylebone Diagnostic Centre?
Marylebone Diagnostic Centre provides discreet and professional prostate testing in a supportive environment, with fast turnaround times and clear communication.
Our experienced clinical team helps you understand your results and next steps, ensuring you feel informed and reassured throughout the process.
Frequently asked questions
When will I receive my results?
Should I discuss my results with a doctor?
