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Prostate Specific Antigen

Prostate specific antigen (PSA) is a biomarker that is known to be reflective of prostate cancer risk. An elevated PSA is associated with greater risk of protate cancer, and reducing the rate that PSA increases is seen as protective.

Research analysis led by Kamal Patel.
All content reviewed by the Examine.com Team. Published: Jul 5, 2013
Last Updated:

Things To Know & Note

Also Known As


Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect prostate specific antigen
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-c Minor Very High See 2 studies
Has been noted to decrease prostate specific antigen levels following supplementation
grade-c - Very High See 2 studies
No significant influence on PSA levels
grade-c - - See study
No significant influence on prostate specific antigen levels
grade-c - Very High See 2 studies
The ethanolic extract has failed to alter serum levels of PSA
grade-c Low See all 4 studies
While observational data suggests a decrease, trials have found no change in PSA levels.
grade-d Notable - See study
The lone study (no placebo control) noted a 60% reduction in both total and free PSA in a small group of men with prostate cancer; requires more evidence to evaluate the therapeutic potential
grade-d Minor Very High See 2 studies
Does not appear to be able to reduce PSA levels outright, although it can attenuate the rate of which PSA increases over time (relative to untreated control, this is a reduction)
grade-d Minor - See study
One study found a significant increase relative to placebo with 2.25 g of a tribulus extract per day.