Juglans nigra

Black walnut/Drug Interactions:

  • GeneralGeneral: Based on anecdote, concomitant oral administration of black walnut hulls with prescription or non-prescription drugs may theoretically cause precipitation of these agents, due to the high tannin content of black walnut hulls. It is recommended that consumption of oral drugs that contain high levels of tannins be separated by at least two hours.
  • AntiemeticsAntiemetics: Based on anecdote, black walnut has been used to relieve constipation and diarrhea due to a normalizing effect that juglone may exert on intestinal tissue. High doses of black walnut may stimulate strong bowel activity, which may worsen chronic stomach or intestinal conditions.
  • AntihypertensivesAntihypertensives: In in vitro study, black walnut extract was shown to have vasoconstrictive effects (5; 6).
  • Anti-inflammatory agents, COX-2 inhibitorsAnti-inflammatory agents, COX-2 inhibitors: Based on laboratory and animal study, black walnut extract influences inflammatory processes (16; 17; 18) that are possibly mediated by COX-2 protein expression (12; 13).
  • Antimicrobial agentsAntimicrobial agents: In laboratory study, Juglans nigra displayed a high level of activity against Listeria monocytogenes (19).
  • AntineoplasticsAntineoplastics: Based on in vitro study, juglone and plumbagin, two quinone constituents of black walnut, may decrease cell viability that may be responsible for cytotoxic effects (1). Black walnut contains tannins; therefore, taking black walnut for extended periods of time may result in some types of oral and esophageal cancer and liver damage.
  • Gastrointestinal agentsGastrointestinal agents: Based on secondary sources, black walnut may contain high levels of tannins, may cause upset stomach when taken orally, may stimulate strong bowel activity, and may result in some types of oral and esophageal cancer and liver damage when taken for extended periods of time.
  • Hepatotoxic agentsHepatotoxic agents: Black walnut contains tannins; therefore, taking black walnut for extended periods of time may result in liver damage.
  • Nephrotoxic agentsNephrotoxic agents: Black walnut contains tannins; therefore, taking black walnut for extended periods of time may result in kidney damage.
  • Stimulant laxativesStimulant laxatives: Based on secondary sources, black walnut may stimulate strong bowel activity.
  • VasopressorsVasopressors: In in vitro study, black walnut extract was shown to have vasoconstrictive effects (5; 6).
  • Black walnut/Herb/Supplement Interactions:

  • GeneralGeneral: Based on anecdote, concomitant oral administration of black walnut hulls with prescription drugs, non-prescription drugs, or dietary supplements may theoretically cause precipitation of these agents, due to the high tannin content of black walnut hulls. It is recommended that consumption of oral drugs that contain high levels of tannins be separated by at least two hours.
  • AntiemeticsAntiemetics: Based on anecdote, black walnut has been used to relieve constipation and diarrhea due to a normalizing effect that juglone may exert on intestinal tissue. High doses of black walnut may stimulate strong bowel activity, which may worsen chronic stomach or intestinal conditions.
  • Anti-inflammatory herbs and supplementsAnti-inflammatory herbs and supplements: Based on laboratory and animal study, black walnut extract influences inflammatory processes (16; 17; 18) that are possibly mediated by COX-2 protein expression (12; 13).
  • AntimicrobialsAntimicrobials: In laboratory study, Juglans nigra displayed a high level of activity against Listeria monocytogenes (19).
  • AntineoplasticsAntineoplastics: Based on in vitro study, juglone and plumbagin, two quinone constituents of black walnut, may decrease cell viability that may be responsible for cytotoxic effects (1). Black walnut contains tannins; therefore, taking black walnut for extended periods of time may result in some types of oral and esophageal cancer and liver damage.
  • AntioxidantsAntioxidants: Black walnut contains peroxynitrite, a cytotoxicant constituent with strong oxidizing properties toward various cellular constituents, including lipids and amino acids (2).
  • Gastrointestinal herbs and supplementsGastrointestinal herbs and supplements: Based on secondary sources, black walnut may contain high levels of tannins, may cause upset stomach when taken orally, may stimulate strong bowel activity, and may result in some types of oral and esophageal cancer and liver damage when taken for extended periods of time.
  • Hepatotoxic herbs and supplementsHepatotoxic herbs and supplements: Black walnut contains tannins; therefore, taking black walnut for extended periods of time may result in liver damage.
  • HypotensivesHypotensives: In in vitro study, black walnut extract was shown to have vasoconstrictive effects (5; 6).
  • Nephrotoxic herbs and supplementsNephrotoxic herbs and supplements: Black walnut contains tannins; therefore, taking black walnut for extended periods of time may result in kidney damage.
  • Stimulant laxativesStimulant laxatives: Based on secondary sources, black walnut may stimulate strong bowel activity.
  • Tannin containing herbs and supplementsTannin containing herbs and supplements: Black walnut reportedly contains high levels of tannins. Concomitant oral administration of black walnut hulls with other oral agents may theoretically cause precipitation of these agents, due to the high tannin content of black walnut hulls.
  • VasopressorsVasopressors: In in vitro study, black walnut extract was shown to have vasoconstrictive effects (5; 6).
  • Black walnut/Food Interactions:

  • Tannin containing foodsTannin containing foods: Black walnut reportedly contains high levels of tannins. Concomitant oral administration of black walnut hulls with other oral agents may theoretically cause precipitation of these agents, due to the high tannin content of black walnut hulls.
  • Black walnut/Lab Interactions:

  • Blood pressureBlood pressure: In in vitro study, black walnut extract was shown to have vasoconstrictive effects (5; 6).