Sabal serrulata

Saw palmetto/Drug Interactions:

  • AndrogensAndrogens: In vitro, saw palmetto has been shown to have antiandrogenic properties (19; 20; 21).
  • Anti-androgensAnti-androgens: In vitro, saw palmetto has been shown to have antiandrogenic properties (19; 20; 21).
  • AntibioticsAntibiotics: In human research, saw palmetto extract plus combination pharmacological therapy with known antibacterial agents (ciprofloxacin/azithromycin) and alpha-blockers (alfuzosin) exhibited microbiological eradication and symptom attenuation in individuals with chronic bacterial prostatitis (22). A combination formulation of S. repens, indol-3-carbinol, and epigallocatexin-3-gallate (indigal plus) has also been shown to improve the rate of bacterial eradication in individuals with chronic infectious prostatitis, with a lower proportion of individuals demonstrating bacterial colonization by chlamydia, ureaplasma, and E. coli compared to sparfloxacin, a known antibiotic therapy (82).
  • Anticoagulants and antiplateletsAnticoagulants and antiplatelets: In case reports, severe intraoperative hemorrhage and prolonged bleeding time (36) and cerebral hemorrhage (35) have been noted with use of saw palmetto.
  • AntihypertensivesAntihypertensives: Occasional cases of hypertension have been reported in controlled trials: 3.1% of a sample of 551 subjects treated with saw palmetto (Permixon? 320mg) vs. 2.2% of 542 subjects treated with finasteride 5mg (statistical significance not known) (9); two subjects in a controlled trial of 238 patients randomized to saw palmetto 320mg or placebo (37); and 6% of 50 patients with benign prostatic hypertrophy (BPH) taking saw palmetto (Permixon? 320mg) in a controlled trial (35). In a randomized controlled trial, increased blood pressure was reported with use of saw palmetto extract; however, this lacked statistical significance compared to the placebo group (12). According to a review, incidences of postural hypotension have also been seen in clinical trials, although a determination of relatedness to saw palmetto was lacking and the rate of occurrence was similar to that seen with placebo (15).
  • Anti-inflammatoriesAnti-inflammatories: In preliminary research, saw palmetto has been shown to have anti-inflammatory properties (83; 84; 23).
  • AntineoplasticsAntineoplastics: Antiproliferative and proapoptotic properties have been attributed to saw palmetto based on the results of in vitro studies (85; 86; 87; 88; 89; 48).
  • Cytochrome P450-metabolized agentsCytochrome P450-metabolized agents: In vivo research in healthy humans has shown that saw palmetto lacks a significant effect on CYP1A2, CYP2D6, CYP2E1, or CYP3A4 activity (90; 91; 61).
  • Disulfiram(Antabuse?)Disulfiram(Antabuse?): Many saw palmetto tinctures contain high levels of alcohol and may cause nausea or vomiting when taken with metronidazole (Flagyl?) or disulfiram (Antabuse?).
  • Drugs that may lower seizure thresholdDrugs that may lower seizure threshold: Theoretically, saw palmetto may have additive effects with agents that lower the seizure threshold.
  • Gastrointestinal agentsGastrointestinal agents: Multiple reports exist in human research of mild-to-moderate gastrointestinal symptoms, including nausea, diarrhea, and abdominal discomfort with use of saw palmetto (41; 15; 16; 42; 43).
  • Genitourinary tract agentsGenitourinary tract agents: Controlled trials and open studies have reported occasional genitourinary effects associated with saw palmetto, most commonly related to sexual dysfunction, particularly ejaculatory dysfunction, erectile dysfunction, and reduced libido (15; 12; 58). Small, statistically significant increases in PSA levels, or nonsignificant increases in PSA levels, have been reported in association with saw palmetto in some human research (55; 52; 12); however, consistent findings among studies are lacking (9; 75), and in other human research, saw palmetto (Permixon?) has been shown to reduce prostate-specific antigen (PSA) levels compared to baseline (52; 54). Saw palmetto, either alone or in combination with other plants (e.g., Pinus pinaster, Urtica dioica), has also been shown to improve various outcomes related to urinary function, including dysuria, nocturia, nocturnal pollakiuria, and micturition rate (42; 92).
  • Heart rate-regulating agentsHeart rate-regulating agents: In a randomized controlled trial, arrhythmia was reported with use of saw palmetto extract; however, this lacked statistical significance compared to the placebo group (12).
  • Hematological agentsHematological agents: In human research, saw palmetto has been shown to reduce levels of hemoglobin, hematocrit, red blood cells, and platelets (44; 45).
  • HepatotoxinsHepatotoxins: Case reports have suggested that saw palmetto may be associated with acute hepatitis, pancreatitis, liver damage, or liver toxicity (38; 39; 40). A case report documented protracted cholestatic hepatitis in a 65 year-old man after a two-week trial of Prostata? (zinc picolinate, pyridoxine, L-alanine, glutamic acid, Apis mellifica pollen, silica, hydrangea extract, Panex ginseng, Serenoa serrulata, and Pygeum africanum) (74). The patient was found to have elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), alkaline phosphatase, and bilirubin, which resolved after discontinuation of saw palmetto.
  • Hormonal agentsHormonal agents: In vitro, saw palmetto has been shown to have antiandrogenic properties (19; 20; 21).
  • ImmunostimulantsImmunostimulants: Saw palmetto has been shown to stimulate macrophage phagocytosis and natural killer (NK) cell synthesis of interferon-gamma in vitro (27).
  • ImmunosuppressantsImmunosuppressants: Saw palmetto has been shown to stimulate macrophage phagocytosis and natural killer (NK) cell synthesis of interferon-gamma in vitro (27).
  • Impotence agentsImpotence agents: Controlled trials and open studies have reported occasional genitourinary effects associated with saw palmetto, most commonly related to sexual dysfunction, particularly ejaculatory dysfunction, erectile dysfunction, and reduced libido (15; 12; 58).

    • Saw palmetto/Herb/Supplement Interactions:

  • Androgenic herbs and supplementsAndrogenic herbs and supplements: In vitro, saw palmetto has been shown to have antiandrogenic properties (19; 20; 21).
  • Anti-androgenic herbs and supplementsAnti-androgenic herbs and supplements : In vitro, saw palmetto has been shown to have antiandrogenic properties (19; 20; 21).
  • AntibacterialsAntibacterials: In human research, saw palmetto extract plus combination pharmacological therapy with known antibacterial agents (ciprofloxacin/azithromycin) and alpha-blockers (alfuzosin) exhibited microbiological eradication and symptom attenuation in individuals with chronic bacterial prostatitis (22). A combination formulation of S. repens, indol-3-carbinol, and epigallocatexin-3-gallate (indigal plus) has also been shown to improve the rate of bacterial eradication in individuals with chronic infectious prostatitis, with a lower proportion of individuals demonstrating bacterial colonization by chlamydia, ureaplasma, and E. coli compared to sparfloxacin, a known antibiotic therapy (82).
  • Anticoagulants and antiplateletsAnticoagulants and antiplatelets: In case reports, severe intraoperative hemorrhage and prolonged bleeding time (36) and cerebral hemorrhage (35) have been noted with use of saw palmetto.
  • Anti-inflammatoriesAnti-inflammatories: In preliminary research, saw palmetto has been shown to have anti-inflammatory properties (83; 84; 23).
  • AntineoplasticsAntineoplastics: Antiproliferative and proapoptotic properties have been attributed to saw palmetto based on the results of in vitro studies (85; 86; 87; 88; 89; 48).
  • Cat's clawCat's claw: Cat's claw and saw palmetto have been shown to stimulate macrophage phagocytosis in vitro (27).
  • Cytochrome P450-metabolized herbs and supplementsCytochrome P450-metabolized herbs and supplements: In vivo research in healthy humans has shown that saw palmetto lacks a significant effect on CYP1A2, CYP2D6, CYP2E1, or CYP3A4 activity (90; 91; 61).
  • EchinaceaEchinacea: Echinacea and saw palmetto have been shown to stimulate macrophage phagocytosis and NK cell synthesis of interferon-gamma in vitro (27).
  • Gastrointestinal agentsGastrointestinal agents: Multiple reports exist in human research of mild-to-moderate gastrointestinal symptoms, including nausea, diarrhea, and abdominal discomfort with use of saw palmetto (41; 15; 16; 42; 43).
  • Genitourinary tract agentsGenitourinary tract agents: Controlled trials and open studies have reported occasional genitourinary effects associated with saw palmetto, most commonly related to sexual dysfunction, particularly ejaculatory dysfunction, erectile dysfunction, and reduced libido (15; 12; 58). Small, statistically significant increases in PSA levels, or nonsignificant increases in PSA levels, have been reported in association with saw palmetto in some human research (55; 52; 12); however, consistent findings among studies are lacking (9; 75), and in other human research, saw palmetto (Permixon?) has been shown to reduce prostate-specific antigen (PSA) levels compared to baseline (52; 54). Saw palmetto, either alone or in combination with other plants (e.g., Pinus pinaster, Urtica dioica), has also been shown to improve various outcomes related to urinary function, including dysuria, nocturia, nocturnal pollakiuria, and micturition rate (42; 92).
  • Heart rate-regulating agentsHeart rate-regulating agents: In a randomized controlled trial, arrhythmia was reported with use of saw palmetto extract; however, this lacked statistical significance compared to the placebo group (12).
  • HematologicsHematologics: In human research, saw palmetto has been shown to reduce levels of hemoglobin, hematocrit, red blood cells, and platelets (44; 45).
  • HepaticsHepatics: Case reports have suggested that saw palmetto may be associated with acute hepatitis, pancreatitis, liver damage, or liver toxicity (38; 39; 40). A case report documented protracted cholestatic hepatitis in a 65 year-old man after a two-week trial of Prostata? (zinc picolinate, pyridoxine, l-alanine, glutamic acid, Apis mellifica pollen, silica, hydrangea extract, Panex ginseng, Serenoa serrulata, and Pygeum africanum) (74). The patient was found to have elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), alkaline phosphatase, and bilirubin, which resolved after discontinuation of saw palmetto.
  • Herbs/supplements that lower seizure thresholdHerbs/supplements that lower seizure threshold: Theoretically, saw palmetto may have additive effects with agents that lower the seizure threshold.
  • Hormonal agentsHormonal agents: In vitro, saw palmetto has been shown to have antiandrogenic properties (19; 20; 21).
  • HypotensivesHypotensives: Occasional cases of hypertension have been reported in controlled trials: 3.1% of a sample of 551 subjects treated with saw palmetto (Permixon? 320mg) vs. 2.2% of 542 subjects treated with finasteride 5mg (statistical significance not known) (9); two subjects in a controlled trial of 238 patients randomized to saw palmetto 320mg or placebo (37); and 6% of 50 patients with benign prostatic hypertrophy (BPH) taking saw palmetto (Permixon? 320mg) in a controlled trial (35). In a randomized controlled trial, increased blood pressure was reported with use of saw palmetto extract; however, this lacked statistical significance compared to the placebo group (12). According to a review, incidences of postural hypotension have also been seen in clinical trials, although a determination of relatedness to saw palmetto was lacking and the rate of occurrence was similar to that seen with placebo (15).
  • ImmunomodulatorsImmunomodulators: Saw palmetto has been shown to stimulate macrophage phagocytosis and natural killer (NK) cell synthesis of interferon-gamma in vitro (27).
  • Impotence agentsImpotence agents: Controlled trials and open studies have reported occasional genitourinary effects associated with saw palmetto, most commonly related to sexual dysfunction, particularly ejaculatory dysfunction, erectile dysfunction, and reduced libido (15; 12; 58).
  • IronIron: According to secondary sources, the tannins that may be present in saw palmetto may prevent the absorption of iron in the body.
  • Pinus pinasterPinus pinaster: In human research, saw palmetto, either alone or in combination with other plants including Pinus pinaster, has been shown to improve various outcomes related to urinary function, including dysuria, nocturia, nocturnal pollakiuria, and micturition rate (42; 92).
  • PhytoestrogensPhytoestrogens: In vitro, saw palmetto has been shown to have antiandrogenic properties (19; 20; 21).
  • Stinging nettle (Urtica dioica)Stinging nettle (Urtica dioica): In human research, saw palmetto, either alone or in combination with other plants including Urtica dioica, has been shown to improve various outcomes related to urinary function, including dysuria, nocturia, nocturnal pollakiuria, and micturition rate (42; 92).

    • Saw palmetto/Food Interactions:

  • GeneralGeneral: Taking saw palmetto extract with food may decrease the gastrointestinal distress sometimes associated with saw palmetto use.

    • Saw palmetto/Lab Interactions:

  • Blood pressureBlood pressure: Occasional cases of hypertension have been reported in controlled trials: 3.1% of a sample of 551 subjects treated with saw palmetto (Permixon? 320mg) vs. 2.2% of 542 subjects treated with finasteride 5mg (statistical significance not known) (9); two subjects in a controlled trial of 238 patients randomized to saw palmetto 320mg or placebo (37); and 6% of 50 patients with BPH taking saw palmetto (Permixon? 320mg) in a controlled trial (35). In a randomized controlled trial, increased blood pressure was reported with use of saw palmetto extract; however, this lacked statistical significance compared to the placebo group (12). According to a review, incidences of postural hypotension have also been seen in clinical trials, although a determination of relatedness to saw palmetto was lacking and the rate of occurrence was similar to that seen with placebo (15). The effects of saw palmetto on blood pressure and its interactions with hypotensive agents have not been systematically studied.
  • Coagulation panelCoagulation panel: In case reports, severe intraoperative hemorrhage and prolonged bleeding time (36) and cerebral hemorrhage (35) have been noted with use of saw palmetto.
  • Dihydrotestosterone(DHT)Dihydrotestosterone(DHT): A modest but significant decline in prostatic DHT levels was observed in a six-month placebo controlled trial involving 40 men (93). However, conflicting evidence was reported in an open, randomized, placebo controlled study that reported that saw palmetto (Permixon?) may not reduce plasma DHT levels (94).
  • Heart rateHeart rate: In a randomized controlled trial, arrhythmia was reported with use of saw palmetto extract; however, this lacked statistical significance compared to the placebo group (12).
  • Hemoglobin (Hgb)Hemoglobin (Hgb): In human research, saw palmetto has been shown to reduce levels of hemoglobin, hematocrit, red blood cells, and platelets (44; 45).
  • Hormone panelHormone panel: In vitro, saw palmetto has been shown to have antiandrogenic properties (19; 20; 21).
  • Liver function tests (LFTs)Liver function tests (LFTs): Case reports have suggested that saw palmetto may be associated with acute hepatitis, pancreatitis, liver damage, or liver toxicity (38; 39; 40). A case report documented protracted cholestatic hepatitis in a 65 year-old man after a two-week trial of Prostata? (zinc picolinate, pyridoxine, L-alanine, glutamic acid, Apis mellifica pollen, silica, hydrangea extract, Panex ginseng, Serenoa serrulata, and Pygeum africanum) (74). The patient was found to have elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), alkaline phosphatase, and bilirubin, which resolved after discontinuation of saw palmetto.
  • Prostate-specific antigen (PSA)Prostate-specific antigen (PSA): In theory, PSA (prostate-specific antigen) levels may be artificially lowered by saw palmetto, based on a proposed mechanism of action of saw palmetto (inhibition of 5-alpha-reductase). Therefore, there may be a delay in diagnosis of prostate cancer or interference with PSA levels during treatment or monitoring in men with known prostate cancer. Small, statistically significant increases in PSA levels have been reported in association with saw palmetto in some human research (55; 52); however, consistent findings among studies are lacking (9; 75), and in other human research, saw palmetto (Permixon?) has been shown to reduce prostate-specific antigen (PSA) levels compared to baseline (52; 54).