Supplement · Grade B

Saw Palmetto and medications.

Every documented pair, every citation. Below: 2 documented pairs grouped by mechanism.

Saw Palmetto is in the Distil supplement database, evidence Grade B. The page below lists every medication we have explicitly assessed it against.

Saw palmetto is a fatty-acid extract from the berries of a dwarf palm, used to ease the urinary symptoms of benign prostate enlargement. The evidence is Grade B for reducing BPH symptoms and improving urinary flow, though it is worth knowing that the large Cochrane review found mixed results and some well-run trials saw little benefit over placebo. The studied dose is 320mg standardised to 85 to 95 percent fatty acids. This one is strictly for men aged 45 and over: there is no benefit signal below that age, and the effects on the testosterone axis are not desirable in younger men or in women, so it should not be included for them. On interactions, it has mild blood-thinning activity, so it should be flagged for anyone taking an anticoagulant. Side effects tend to be mild stomach upset and occasionally reduced libido. A practical note: track urinary symptoms over a couple of months and review with your GP if they do not shift.

Below are the 2 documented pairs we have explicitly assessed for Saw Palmetto: 2 amber. The pairs cluster around 1 mechanism: Additive 5-alpha-reductase inhibition. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.

Documented interactions

Additive 5-alpha-reductase inhibition

Amber Dutasteride

Saw palmetto and dutasteride both act on the same enzyme that converts testosterone to its more active form. Taking them together adds a second source of the same effect, which is usually not dangerous but is worth raising with your prescriber so your treatment can be looked at as a whole. Dutasteride lowers your PSA reading, which doctors track for prostate health. Saw palmetto does not appear to lower PSA on its own, so it should not add to that effect or further mask the reading.

PMID 15543614 · PMID 16985705 · PMID 12674456 · PMID 16467543 · PMID 21954478 · BNF: Dutasteride

Reviewer-flagged: awaiting clinical-reviewer sign-off.

Amber Finasteride

Saw palmetto and finasteride both act on the same enzyme that converts testosterone to its more active form. Taking them together adds a second source of the same effect, which is usually not dangerous but is worth raising with your prescriber so your treatment can be assessed as a whole. Unlike finasteride, saw palmetto does not appear to lower PSA, so it should not mask PSA-based prostate monitoring.

PMID 15543614 · PMID 16985705 · PMID 12674456 · BNF: Finasteride

Reviewer-flagged: awaiting clinical-reviewer sign-off.

What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.

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