From the Guidelines
PSA levels can remain elevated for up to 48 hours after sexual intercourse, and it is recommended to abstain from ejaculation for at least 2 days before a PSA test to ensure accurate results. This is based on the guidelines from the National Comprehensive Cancer Network, which suggest that ejaculation can temporarily increase PSA levels in the bloodstream, potentially leading to falsely elevated results 1. The elevation occurs because during ejaculation, the prostate releases PSA into the seminal fluid, and some of this PSA can leak into the bloodstream.
Some key points to consider when interpreting PSA results include:
- Ejaculation can increase PSA levels, but the effect is variable and may be insignificant in some cases 1
- Other activities that might affect PSA levels include vigorous exercise, recent urinary tract infections, prostate manipulation during medical exams, or prostate biopsies
- Medications such as finasteride and dutasteride can lower PSA levels by approximately 50% regardless of the dose 1
- Laboratory variability can range from 20-25% depending on the type of standardization used, and it is necessary to use the same assay for longitudinal monitoring 1
It is essential to consider these factors when interpreting PSA results to ensure accurate diagnosis and treatment. If you've recently engaged in sexual activity and received an elevated PSA result, your doctor might recommend repeating the test after an appropriate abstinence period to get a more accurate baseline reading.
From the Research
Effect of Ejaculation on PSA Levels
- Ejaculation can cause a significant increase in serum prostate-specific antigen (PSA) levels, with studies showing an increase in PSA levels after ejaculation 2, 3, 4, 5.
- The increase in PSA levels after ejaculation can persist for up to 24-48 hours, with one study showing that 92% of subjects returned to baseline by 24 hours and 97% by 48 hours 4.
- However, not all studies have shown a significant increase in PSA levels after ejaculation, with one study finding no statistically significant changes in serum PSA levels 1 and 24 hours after ejaculation in young men 6.
- The effect of ejaculation on PSA levels may be age-related, with one study showing a stronger correlation between absolute change in PSA and age in older men 4.
- The clinical significance of the increase in PSA levels after ejaculation is still debated, with some studies suggesting that it may lead to false positive results and unnecessary work-ups, particularly in men over 50 years old with high American Urologic Association (AUA) scores 5.
Time Course of PSA Levels After Ejaculation
- PSA levels can increase significantly 1 hour after ejaculation, with one study showing a mean absolute PSA change of 0.8 ng/mL and a mean relative PSA change of 41% 4.
- PSA levels may remain elevated 6 hours after ejaculation, but tend to return to baseline levels by 24 hours 2, 4.
- One study showed that 40% of men had total PSA levels above baseline 24 hours after ejaculation, while another study found that 2.12% of patients had biopsy decisions that could be affected by the elevation in PSA levels after ejaculation 2, 3.
Factors Influencing PSA Levels After Ejaculation
- Baseline PSA levels may influence the magnitude of the increase in PSA levels after ejaculation, with one study showing a strong correlation between absolute change in PSA and baseline serum PSA 4.
- Age may also be a factor, with older men showing a stronger correlation between absolute change in PSA and age 4.
- The AUA score may also be related to PSA levels after ejaculation, with one study showing a positive correlation between PSA levels and AUA score in men over 50 years old 5.