Saw Palmetto and medications.
Saw Palmetto is in the Distil supplement database, evidence Grade C. 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 C, and the honest position is that the best available trials do not support it. Cochrane's pooled estimate, drawn from two high-quality long-term trials in 582 men, found no benefit over placebo on urinary symptom scores; the full review covered 32 randomised trials and 5,666 men. A further trial that escalated to triple the usual dose, which is the design most likely to show an effect if one exists, slightly favoured 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
Last reviewed 14 June 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
Additive 5-alpha-reductase inhibition
Amber Does interact with Dutasteride?
Taking saw palmetto with dutasteride adds a second source of the same effect, because both act on the enzyme that converts testosterone to its more active form; this 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.
Evidence: Based on an established mechanism, with no direct study of this exact combination yet.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does interact with Finasteride?
Taking saw palmetto with finasteride adds a second source of the same effect, because both act on the enzyme that converts testosterone to its more active form; this 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.
Evidence: Based on an established mechanism, with no direct study of this exact combination yet.
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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How we grade severity, choose what's in scope, and what we exclude.
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