Capsicum annuum

Cayenne/Drug Interactions:

  • ACE inhibitorsACE inhibitors: Capsaicin induced cough in patients using ACE inhibitors (174; 175; 176; 174). In animal research, capsaicin caused hypertension, particularly in high doses (150).
  • AlcoholAlcohol: In humans, capsaicin has been shown to have gastroprotective effects against ethanol (372).
  • AnalgesicsAnalgesics: According to various reviews, Capsicum species may topically reduce pain by activating neurons and depleting stores of the neurotransmitter substance P, thus desensitizing neurons to pain (2; 3; 2; 4; 373; 374). However, in human pain models, analgesics have been used to reduce pain associated with capsaicin or Capsicum (310; 311; 375; 376; 377; 378; 379; 380; 381; 382).
  • Androgenic agentsAndrogenic agents: In vitro, capsaicin induced an increase in androgen receptor expression, likely due to binding to TRPV1 (242).
  • AntibioticsAntibiotics: In vitro, capsaicin inhibited the growth of various bacteria (383; 384; 385; 386), including Helicobacter pylori (383), but there was a lack of an effect observed in human research (210). In animals, capsaicin increased cefazolin absorption (387) and increased bioavailability of ciprofloxacin (388).
  • Anticoagulants and antiplateletsAnticoagulants and antiplatelets: The potential effect of Capsicum on increased risk of bleeding has been reviewed (147). In vitro, capsaicin reduced platelet aggregation and increased fibrinolytic activity (144; 145). Cayenne was one of various complementary and alternative therapies associated with increased risk of self-reported bleeding in patients receiving warfarin (146).
  • AnticonvulsantsAnticonvulsants: According to secondary sources, Capsicum may interact with antiseizure medications causing increased sleepiness.
  • Antidepressants, monoamine oxidase inhibitors (MAOIs)Antidepressants, monoamine oxidase inhibitors (MAOIs): According to secondary sources, capsaicin may interfere with neurotransmitters, which are also affected by MAO inhibitors.
  • AntidiabeticsAntidiabetics: In animal and human research, capsaicin reduced blood glucose and increased plasma insulin (49; 181; 182). In human research, consumption of cayenne chili attenuated postprandial hyperinsulinemia (48). In rats, red chili had insulinotropic, but not hypoglycemic effects (389). In dogs, capsaicin decreased blood glucose levels and increased plasma insulin with decreased binding of insulin to its receptor (50).
  • AntifungalsAntifungals: In vitro, a steroidal saponin isolated from the ground fruit of Capsicum frutescens has been shown to be a potent fungicide for Candida and Aspergillus spp. (390; 391). According to a review, lipid transfer proteins from chili pepper have anti-fungal effects (392).
  • AntihypertensivesAntihypertensives: In animal research, capsaicin caused hypertension, particularly in high doses (150). In case reports, arterial hypertensive crisis and acute myocardial infarction were reported (148; 149).
  • Anti-inflammatoriesAnti-inflammatories: In humans, capsaicin suppressed histamine-induced itching in healthy skin (393) and inhibited the flare and weal components of the cutaneous allergy reaction (394; 395; 396). In vitro, capsaicin inhibited Jurkat T cell activation by blocking calcium entry (397) and reduced mRNA levels of cytokines (398). In vitro, capsaicin enhanced skin permeation of naproxen (399). In animals treated with desoxycorticosterone acetate, submucous fibrosis of the palate was induced by local painting with capsaicin (304). Capsaicin was shown to have gastroprotective effects against indomethacin in humans (372).
  • AntilipemicsAntilipemics: In animals, Capsicum reduced cholesterol levels (400). In human research, use of a fermented red pepper paste as part of a combination product had lipid lowering effects (77).
  • AntineoplasticsAntineoplastics: In vitro, capsaicin induced apoptosis (401) and was shown to have antiproliferative (402) and antiangiogenic (403) effects in cancer cell lines. The cancer-promoting and anticancer effects of various plant phenolics, including capsaicin, have been reviewed (35; 13; 236; 237; 238; 37; 404; 405).
  • Antiobesity agentsAntiobesity agents: In human research, consumption of cayenne chili attenuated postprandial hyperinsulinemia (48), and increased carbohydrate oxidation both at rest and during exercise (406). In human research, capsaicin or other constituents of Capsicum, as well as intake of red pepper, increased energy expenditure, fat oxidation, and body temperature (407; 408; 409; 410; 411) and promoted a negative fat balance (412). In animals, capsaicin induced thermogenesis (413), and in humans, dihydrocapsiate had a small thermogenic effect (414). Constituents other than capsaicinoids have also been investigated for weight loss effects in humans, with positive benefits from the nonpungent capsinoids in some (415), but not all (416), studies.
  • AntiparasiticsAntiparasitics: In vitro, extracts from the leaves of Capsicum annuum resulted in the death of the cercaria of Schistosoma mansoni within 15 minutes (417). The active principles appeared to be water-soluble unsaturated compounds from the oils or their hydrolysis products.
  • AntipyrineAntipyrine: In animal research, intravenous capsaicin reduced the clearance of antipyrine, consistent with a prolongation in the elimination half-life (418).
  • AntispasmodicsAntispasmodics: According to secondary sources, cayenne has antispasmodic properties.
  • Antiulcer and gastric acid-reducing agentsAntiulcer and gastric acid-reducing agents: According to secondary sources, Capsicum may increase stomach acid and therefore may interfere with antiulcer agents including H2-blockers and proton pump inhibitors.
  • AntiviralsAntivirals: In animals, capsaicin protected against cutaneous herpes simplex virus disease (419). However, it was suggested that the effect was not due to direct antiviral activity but to another mechanism.
  • AspirinAspirin: In animals, Capsicum decreased blood levels of aspirin (172). Capsaicin was shown to have gastroprotective effects against aspirin in animals (420). No subjects without preexisting gastritis developed acute gastritis after ingesting aspirin with chili (421). In human research, acetylsalicylic acid (aspirin) counteracts the excitatory effects of capsaicin on nociceptors and mechanical hyperalgesia but not its sensitizing action to heat (422). Interactions between cayenne and aspirin were the topic of a general review on herbal supplements and drug interactions (423).
  • Beta-blockersBeta-blockers: In human research, propranolol partly abolished the thermogenic response of capsaicin in combination with tyrosine, catechins, and caffeine (424).
  • CaffeineCaffeine: In vitro, caffeine triggered acute desensitization to capsaicin (425). In human research, capsaicin, as part of a product also containing raspberry ketone, caffeine, garlic, ginger and Citrus aurantium (Prograde MetabolismT) resulted in a decrease in body weight, fat mass, waist girth, and hip girth, and increased lean mass and energy levels (426).
  • CannabinoidsCannabinoids: In isolated lamb detrusor, cannabinoids had a lack of an effect on capsaicin-induced responses (427). In human research, delta-9-tetrahydrocannabinol (THC) reduced the reported unpleasantness associated with pain due to capsaicin, but effects on the intensity of ongoing pain and hyperalgesia were lacking (382).
  • CapsazepineCapsazepine: In vitro, capsazepine, a synthetic analog of capsaicin and vanilloid receptor (VR1) antagonist, acts as an antagonist to capsaicin-induced currents (428).
  • Cardiovascular agentsCardiovascular agents: The use of cayenne pepper pills resulted in a case of acute myocardial infarction (293) and topical capsaicin resulted in a case of coronary vasospasm and acute myocardial infarction (294).
  • CGRP receptor antagonistsCGRP receptor antagonists: A capsaicin-induced increase in dermal blood flow was used as a human model to examine the efficacy and mechanism of action of oral CGRP receptor antagonists, such as telcagepant, for migraines (139; 140).
  • CNS depressantsCNS depressants: According to secondary sources, Capsicum may cause additive sedation when used with CNS depressants. The effect of capsaicin on hexobarbital-anesthetized rats was discussed in early study (429). Further details are lacking.
  • CocaineCocaine: According to case reports, a combination of Capsicum spray and cocaine may increase the risk of death (430; 431).
  • Cytochrome P450-metabolized agentsCytochrome P450-metabolized agents: In vitro, capsaicin is metabolized by cytochrome P450 enzymes (178; 179; 180). Metabolism was catalyzed by CYP1A1, 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4. According to reviews, capsaicin and other constituents of chili inhibit cytochrome P450 enzymes (37; 177).
  • Dental agentsDental agents: In vitro, capsaicin-evoked the release of iCGRP from human dental pulp; this release was used as part of a model system for the study of peripheral neuropeptide secretion in normal healthy tissue (432).
  • Dermatological agentsDermatological agents: A burning sensation at the application site and local skin irritation have been noted in some subjects; this has been shown in many clinical trials of capsaicin itself (152; 93; 153; 154; 155).
  • Gastrointestinal agentsGastrointestinal agents: In humans, pungent Capsicum annuum species were shown to improve the motor performance of the esophageal body in patients with ineffective motility (433) and to increase the gastric emptying rate (434). In animals, capsaicin caused gastric hyperemia and healing of acetic acid-induced ulcers (435) and reduced gastric mucosal injury (436). In vitro, capsaicin inhibited the growth of Helicobacter pylori (383), but there was a lack of an effect observed in humans (210). In clinical trial, dyspepsia, increased abdominal pain, gastric distress, anal burning, and decreased food palatability have been reported (164; 163).
  • ImmunosuppressantsImmunosuppressants: In vitro, capsaicin and an extract of Capsicum annuum resulted in suppression of IL-2, interferon (IFN)-gamma, IL-4, and IL-5 production; ex vivo production of IL-2, IFN-gamma, and IL-5 was increased in response to concanavalin A (Con A) following oral treatment in animal study (437). Furthermore, flow cytometric analysis revealed a reduced population of CD3(+) cells and an increase in CD19(+) cells. In vitro, immunomodulatory effects have also been shown (438; 397).
  • Isopropyl alcoholIsopropyl alcohol: In humans, isopropyl alcohol increased the amount of capsaicin penetration into the human stratum corneum (439).
  • LidocaineLidocaine: Inhalation of lidocaine reduced the cough provocation associated with capsaicin, used as an objective way to test sensory hyperreactivity in patients with asthma-like symptoms (323).
  • MorphineMorphine: In animals, capsaicinoids induced an increase in nerve firing capacity, which was inhibited by morphine (440).
  • NabiloneNabilone: In human research, nabilone lacked effect on capsaicin-induced pain and hyperalgesia (354).
  • NaloxoneNaloxone: In animal research, capsaicinoids induced an increase in nerve firing capacity, which was inhibited by morphine; naloxone antagonized this effect (440).
  • NitratesNitrates: In human research, topical application of glyceryl nitrate reduced thermal allodynia caused by capsaicin cream (441).
  • OlapatadineOlapatadine: In human research, olopatadine hydrochloride inhibited capsaicin-induced flare response (290).
  • PesticidesPesticides: In vitro, fruit extracts of various hot pepper species were found to have insecticidal effects (74; 442) and addition of capsaicin to poultry feed resulted in reduced consumption by rodents (443), although results are conflicting as roses surrounded by sachets with crushed red pepper had significantly more beetles than the control plants (444).
  • P-glycoprotein-regulated drugsP-glycoprotein-regulated drugs: In vitro, capsaicin modulated p-glycoprotein expression and activity (445; 446). Modulation of p-glycoprotein has been the topic of a review (447).
  • PropranololPropranolol: In human research, propranolol partly abolished the thermogenic response of capsaicin in combination with tyrosine, catechins, and caffeine (424).
  • QuinineQuinine: In animal research, capsaicin had a lack of an effect on the pharmacokinetics of quinine (418).
  • Renal agentsRenal agents: According to secondary sources, eating too much Capsicum may cause kidney damage. Symptoms may include a change in the amount of urine production.
  • ResiniferatoxinResiniferatoxin: In vitro, capsaicin and resiniferatoxin, a capsaicin analog, may compete for binding on cell receptor sites, activate downstream effects, and induce similar responses to capsaicin (448; 449).
  • Respiratory agentsRespiratory agents: Cough reflex sensitivity to capsaicin is used as a testing mechanism in human pharmacological and clinical research (320; 322; 323; 324; 325; 326; 327; 328; 329; 330; 331). The cough sensitivity to capsaicin is used to the clinical evaluation of cough suppressants, such as benzonatate and guaifenesin (450). In human research, capsaicin desensitized nasal mucosa and reduced allergic symptoms of nasal allergy or pain induced by other agents (451; 452).
  • SedativesSedatives: According to secondary sources, Capsicum may cause additive sedation when used with sedatives.
  • SucralfateSucralfate: According to secondary sources, caution is advised, as combination with cayenne may decrease sucralfate efficacy.
  • TheophyllineTheophylline: In animals, Capsicum increased blood levels of theophylline (173); however, this was not observed in other studies (418).
  • TobaccoTobacco: In animal research, capsaicin was not protective against tobacco-induced lung cancer (453). However, capsaicin did modify the metabolism of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (454; 455; 456).
  • TriptansTriptans: According to secondary sources, Capsicum may interact with antimigraine agents.
  • ValdecoxibValdecoxib: In vitro, Capsicum annuum induced biotransformation of valdecoxib into more polar compounds, using hydroxylation, methylation, or demethylation (457).
  • VasodilatorsVasodilators: In humans, capsaicin increased cutaneous and arterial vasodilation (458; 459; 460; 461; 172; 372; 421; 422).

    • Cayenne/Herb/Supplement Interactions:

  • AnalgesicsAnalgesics: According to various reviews, Capsicum species may topically reduce pain by activating neurons and depleting stores of the neurotransmitter substance P, thus desensitizing neurons to pain (2; 3; 2; 4; 373; 374). However, in human pain models, analgesics have been used to reduce pain associated with capsaicin or Capsicum (310; 311; 375; 376; 377; 378; 379; 380; 381; 382).
  • AndrogensAndrogens: In vitro, capsaicin induced an increase in androgen receptor expression, likely due to binding to TRPV1 (242).
  • AntibacterialsAntibacterials: In vitro, capsaicin inhibited the growth of various bacteria (383; 384; 385; 386), including Helicobacter pylori (383), but there was a lack of an effect observed in human research (210). In animals, capsaicin increased cefazolin absorption (387) and increased bioavailability of ciprofloxacin (388).
  • Anticoagulant and antiplateletsAnticoagulant and antiplatelets: The potential effect of Capsicum on increased risk of bleeding has been reviewed (147). In vitro, capsaicin reduced platelet aggregation and increased fibrinolytic activity (144; 145). Cayenne was one of various complementary and alternative therapies associated with increased risk of self-reported bleeding in patients receiving warfarin (146).
  • AnticonvulsantsAnticonvulsants: According to secondary sources, Capsicum may interact with antiseizure medications causing increased sleepiness.
  • Antidepressants, monoamine oxidase inhibitors (MAOIs)Antidepressants, monoamine oxidase inhibitors (MAOIs): According to secondary sources, capsaicin may interfere with neurotransmitters, which are also affected by MAO inhibitors.
  • AntifungalsAntifungals: In vitro, a steroidal saponin isolated from the ground fruit of Capsicum frutescens has been shown to be a potent fungicide for Candida and Aspergillus spp. (390; 391). According to a review, lipid transfer proteins from chili pepper have anti-fungal effects (392).
  • AnthelminticsAnthelmintics: In vitro, extracts from the leaves of Capsicum annuum resulted in the death of the cercaria of Schistosoma mansoni within 15 minutes (417). The active principles appeared to be water-soluble unsaturated compounds from the oils or their hydrolysis products.
  • Anti-inflammatoriesAnti-inflammatories: In humans, capsaicin suppressed histamine-induced itching in healthy skin (393) and inhibited the flare and weal components of the cutaneous allergy reaction (394; 395; 396). In vitro, capsaicin inhibited Jurkat T cell activation by blocking calcium entry (397) and reduced mRNA levels of cytokines (398). In vitro, capsaicin enhanced skin permeation of naproxen (399). In animals treated with desoxycorticosterone acetate, submucous fibrosis of the palate was induced by local painting with capsaicin (304). Capsaicin was shown to have gastroprotective effects against indomethacin in humans (372).
  • AntilipemicsAntilipemics: In animals, Capsicum reduced cholesterol levels (400). In human research, use of a fermented red pepper paste as part of a combination product had lipid lowering effects (77).
  • AntineoplasticsAntineoplastics: In vitro, capsaicin induced apoptosis (401) and was shown to have antiproliferative (402) and antiangiogenic (403) effects in cancer cell lines. The cancer-promoting and anticancer effects of various plant phenolics, including capsaicin, have been reviewed (35; 13; 236; 237; 238; 37; 404; 405).
  • Antiobesity agentsAntiobesity agents: In human research, consumption of cayenne chili attenuated postprandial hyperinsulinemia (48), and increased carbohydrate oxidation both at rest and during exercise (406). In human research, capsaicin or other constituents of Capsicum, as well as intake of red pepper, increased energy expenditure, fat oxidation, and body temperature (407; 408; 409; 410; 411) and promoted a negative fat balance (412). In animals, capsaicin induced thermogenesis (413), and in humans, dihydrocapsiate had a small thermogenic effect (414). Constituents other than capsaicinoids have also been investigated for weight loss effects in humans, with positive benefits from the nonpungent capsinoids in some (415), but not all (416), studies.
  • AntioxidantsAntioxidants: In human and in vitro research, consumption of cayenne chili decreased the rate of oxidation, increased lag time to lipoprotein oxidation, and had other antioxidant effects (48; 462; 463; 464). Antioxidant activity has been shown by various capsaicinoids, as well as other constituents of Capsicumin vitro (465; 466; 467; 468; 469; 470; 471; 472; 473; 29).
  • AntiparasiticsAntiparasitics: In vitro, extracts from the leaves of Capsicum annuum resulted in the death of the cercaria of Schistosoma mansoni within 15 minutes (417). The active principles appeared to be water-soluble unsaturated compounds from the oils or their hydrolysis products.
  • AntispasmodicsAntispasmodics: According to secondary sources, cayenne has antispasmodic properties.
  • Antiulcer and gastric acid-reducing agentsAntiulcer and gastric acid-reducing agents: According to secondary sources, Capsicum can increase stomach acid and therefore may interfere with antacids.
  • AntiviralsAntivirals: In animals, capsaicin protected against cutaneous herpes simplex virus disease (419). However, it was suggested that the effect was not due to direct antiviral activity but to another mechanism.
  • Apple cider vinegarApple cider vinegar: According to secondary sources, one part cayenne pepper and equal parts mullein leaf, slippery elm powder, and apple cider vinegar (to dampen) have been used for arthritis.
  • CaffeineCaffeine: In vitro, caffeine triggered acute desensitization to capsaicin (425). In human research, capsaicin, as part of a product also containing raspberry ketone, caffeine, garlic, ginger and Citrus aurantium (Prograde MetabolismT) resulted in a decrease in body weight, fat mass, waist girth, and hip girth, and increased lean mass and energy levels (426).
  • CalciumCalcium: Calcium chloride improved firmness of Capsicum peppers and had a lack of an effect on ascorbic acid, flavonoid, or capsaicinoid retention during pasteurization and storage (474).
  • CannabinoidsCannabinoids: In isolated lamb detrusor, cannabinoids had a lack of an effect on capsaicin-induced responses (427). In human research, delta-9-tetrahydrocannabinol (THC) reduced the reported unpleasantness associated with pain due to capsaicin, but effects on the intensity of ongoing pain and hyperalgesia were lacking (382).
  • Cardiovascular agentsCardiovascular agents: The use of cayenne pepper pills resulted in a case of acute myocardial infarction (293) and topical capsaicin resulted in a case of coronary vasospasm and acute myocardial infarction (294).
  • CatechinCatechin: In vitro, catechin vanilloid (capsaicin) combinations were more effective than capsaicin alone for inducing apoptosis of cancer cells (475).
  • Citrus aurantiumCitrus aurantium: In human research, capsaicin, as part of a product also containing raspberry ketone, caffeine, garlic, ginger and Citrus aurantium (Prograde MetabolismT) resulted in a decrease in body weight, fat mass, waist girth, and hip girth, and increased lean mass and energy levels (426).
  • CocaCoca: According to case reports, a combination of Capsicum spray and cocaine may increase the risk of death (430; 431). It is not known if coca would have the same effect.
  • CopperCopper: Copper may be adsorbed onto Capsicum annuum seeds (476).
  • Cytochrome P450-metabolized agentsCytochrome P450-metabolized agents: In vitro, capsaicin is metabolized by cytochrome P450 enzymes (178; 179; 180). Metabolism was catalyzed by CYP1A1, 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4. According to reviews, capsaicin and other constituents of chili inhibit cytochrome P450 enzymes (37; 177).
  • Dental agentsDental agents: In vitro, capsaicin-evoked the release of iCGRP from human dental pulp; this release was used as part of a model system for the study of peripheral neuropeptide secretion in normal healthy tissue (432).
  • Docosahexaenoic acidDocosahexaenoic acid: In vitro, the DHA analog of capsaicin (dohevanil) had a more potent effect on apoptosis induction than capsaicin (477).
  • GarlicGarlic: In human research, capsaicin, as part of a product also containing raspberry ketone, caffeine, garlic, ginger and Citrus aurantium (Prograde MetabolismT) resulted in a decrease in body weight, fat mass, waist girth, and hip girth, and increased lean mass and energy levels (426).
  • Gastrointestinal agentsGastrointestinal agents: In humans, pungent Capsicum annuum species were shown to improve the motor performance of the esophageal body in patients with ineffective motility (433) and to increase the gastric emptying rate (434). In animals, capsaicin caused gastric hyperemia and healing of acetic acid-induced ulcers (435) and reduced gastric mucosal injury (436). In vitro, capsaicin inhibited the growth of Helicobacter pylori (383), but there was a lack of an effect observed in humans (210). In clinical trial, dyspepsia, increased abdominal pain, gastric distress, anal burning, and decreased food palatability have been reported (164; 163).
  • GingerGinger: In human research, capsaicin, as part of a product also containing raspberry ketone, caffeine, garlic, ginger and Citrus aurantium (Prograde MetabolismT) resulted in a decrease in body weight, fat mass, waist girth, and hip girth, and increased lean mass and energy levels (426).
  • HypoglycemicsHypoglycemics: In animal and human research, capsaicin reduced blood glucose and increased plasma insulin (49; 181; 182). In human research, consumption of cayenne chili attenuated postprandial hyperinsulinemia (48). In rats, red chili had insulinotropic, but not hypoglycemic effects (389). In dogs, capsaicin decreased blood glucose levels and increased plasma insulin with decreased binding of insulin to its receptor (50).
  • HypotensivesHypotensives: In animal research, capsaicin caused hypertension, particularly in high doses (150). In case reports, arterial hypertensive crisis and acute myocardial infarction were reported (148; 149).
  • ImmunomodulatorsImmunomodulators: In vitro, capsaicin and an extract of Capsicum annuum resulted in suppression of IL-2, interferon (IFN)-gamma, IL-4, and IL-5 production; ex vivo production of IL-2, IFN-gamma, and IL-5 was increased in response to concanavalin A (Con A) following oral treatment in animal study (437). Furthermore, flow cytometric analysis revealed a reduced population of CD3(+) cells and an increase in CD19(+) cells. In vitro, immunomodulatory effects have also been shown (438; 397).
  • IronIron: In humans, chili pepper reduced iron availability (478).
  • Mullein leafMullein leaf: According to secondary sources, one part cayenne pepper and equal parts mullein leaf, slippery elm powder, and apple cider vinegar (to dampen) have been used for arthritis.
  • PesticidesPesticides: In vitro, fruit extracts of various hot pepper species were found to have insecticidal effects (74; 442) and addition of capsaicin to poultry feed resulted in reduced consumption by rodents (443), although results are conflicting as roses surrounded by sachets with crushed red pepper had significantly more beetles than the control plants (444).
  • P-glycoprotein modulatorsP-glycoprotein modulators: In vitro, capsaicin modulated p-glycoprotein expression and activity (445; 446). Modulation of p-glycoprotein has been the topic of a review (447).
  • PiperinePiperine: In vitro, piperine and capsaicin had synergistic effects on the inhibition of P-glycoprotein-mediated efflux (446).
  • PoppyPoppy: In animals, capsaicinoids induced an increase in nerve firing capacity, which was inhibited by morphine (440).
  • ProbioticsProbiotics: In vitro, Bifidobacterium longum lysate inhibited capsaicin-induced CGRP release by neurones (479).
  • Quinine-containing agentsQuinine-containing agents: In animal research, capsaicin had a lack of an effect on the pharmacokinetics of quinine (418).
  • Raspberry ketoneRaspberry ketone: In human research, capsaicin, as part of a product also containing raspberry ketone, caffeine, garlic, ginger and Citrus aurantium (Prograde MetabolismT) resulted in a decrease in body weight, fat mass, waist girth, and hip girth, and increased lean mass and energy levels (426).
  • Renally eliminated agentsRenally eliminated agents: According to secondary sources, eating too much Capsicum may cause kidney damage. Symptoms may include a change in the amount of urine production.
  • Respiratory agentsRespiratory agents: Cough reflex sensitivity to capsaicin is used as a testing mechanism in human pharmacological and clinical research (320; 322; 323; 324; 325; 326; 327; 328; 329; 330; 331). The cough sensitivity to capsaicin is used to the clinical evaluation of cough suppressants, such as benzonatate and guaifenesin (450). In human research, capsaicin desensitized nasal mucosa and reduced allergic symptoms of nasal allergy or pain induced by other agents (451; 452).
  • Salicylate-containing agentsSalicylate-containing agents: In animals, Capsicum decreased blood levels of aspirin (172). Capsaicin was shown to have gastroprotective effects against indomethacin in humans (372) and aspirin in animals (420). No subjects without pre-existing gastritis developed acute gastritis after ingesting aspirin with chili (421). In human research, acetylsalicylic acid (aspirin) counteracts the excitatory effects of capsaicin on nociceptors and mechanical hyperalgesia but not its sensitizing action to heat (422). Interactions between cayenne and aspirin were the topic of a general review on herbal supplements and drug interactions (423).
  • SedativesSedatives: According to secondary sources, Capsicum may cause additive sedation when used with sedatives.
  • Slippery elmSlippery elm: According to secondary sources, one part cayenne pepper and equal parts mullein leaf, slippery elm powder, and apple cider vinegar (to dampen) have been used for arthritis.
  • TheophyllineTheophylline: In animals, Capsicum increased blood levels of theophylline (173); however, this was not observed in other studies (418).
  • TobaccoTobacco: In animal study, capsaicin was not protective against tobacco-induced lung cancer (453). However, capsaicin did modify the metabolism of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (454; 455; 456).
  • Trans-4-tert-butylcyclohexanolTrans-4-tert-butylcyclohexanol: In vitro, trans-4-tert-butylcyclohexanol inhibited capsaicin-induced TRPV1 activation (480).
  • TyrosineTyrosine: In vitro, tyrosine prevented capsaicin-induced effects by preventing its metabolism (247).
  • VasodilatorsVasodilators: In humans, capsaicin increased cutaneous and arterial vasodilation (458; 459; 460; 461; 172; 372; 421; 422).
  • Vitamin CVitamin C: In vitro, extracts of Capsicum inhibited ascorbate autoxidation (481). Also, ascorbate decreased capsaicinoid radical production in vitro (482) and had protective effects against other Capsicum constituents (483).

    • Cayenne/Food Interactions:

  • AlcoholAlcohol: In humans, capsaicin was shown to have gastroprotective effects against ethanol (372).
  • Acidic foodAcidic food: In humans, capsaicin increased heartburn and postprandial gastroesophageal reflux when capsaicin capsules were taken with heartburn-promoting food (168).
  • BananaBanana: In vitro, polygalacturonase from banana fruit was inhibited by the preparations of the protein inhibitor from Capsicum annuum L. fruit (484).
  • Cocos nuciferaCocos nucifera: In animals, Cocos nucifera reduced the mutagenic and carcinogenic effects of chili (485).

    • Cayenne/Lab Interactions:

  • Blood glucoseBlood glucose: In animal and human research, capsaicin reduced blood glucose (49; 181; 182; 246).
  • Blood pressureBlood pressure: In animal research, capsaicin caused hypertension, particularly in high doses (150). In animal study, capsaicin attenuated blood pressure rise following muscle contraction (486). An increase in blood pressure was also shown in other animal study (148).
  • Body temperatureBody temperature: In human study, capsaicin lowered body and skin temperature, perhaps by stimulating the cooling center in the hypothalamus (487; 488). In separate study, core temperature was increased and skin temperature was decreased (410).
  • CatecholamineCatecholamine: In vitro, capsaicin inhibited catecholamine secretion (489).
  • Coagulation panelCoagulation panel: The potential effect of Capsicum on increased risk of bleeding has been reviewed (147). In vitro, capsaicin has been shown to reduce platelet aggregation and increase fibrinolytic activity (144; 145). Cayenne was one of various complementary and alternative therapies associated with increased risk of self-reported bleeding in patients receiving warfarin (146).
  • CorticotropinCorticotropin: The sites at which capsaicin acts to stimulate corticotropin secretion have been discussed (490). Further details are lacking.
  • CytokinesCytokines: In animal study, juice or extracts of various pungent Capsicum fruit, as well as capsaicin, resulted in reduced tumor necrosis factor-alpha and interleukin-1beta (491). In an obesity model, capsaicin reduced the release of adipokine and other inflammatory mediators (e.g., IL-6) from macrophages (492). In vitro, capsaicin and an extract of Capsicum annuum resulted in a suppression of IL-2, interferon (IFN)-gamma, IL-4, and IL-5 production; ex vivo production of IL-2, IFN-gamma, and IL-5 was increased in response to concanavalin A (Con A) following oral treatment in animal study (437).
  • EpinephrineEpinephrine: In long-distance male runners, pungent Capsicum increased plasma epinephrine and norepinephrine levels (406).
  • Fecal fatFecal fat: In animal research, Capsicum annuum consumption reduced fecal bile acid and neutral sterol levels (244).
  • Free fatty acidsFree fatty acids: In animals, capsaicin reduced olive oil induced increases in various biliary fatty acids, including arachidonic acid (493) and reduced free fatty acid levels (246). In human research, capsaicinoid beadlets increased blood levels of free fatty acids (494).
  • Glucagon like peptide (GLP)-1Glucagon like peptide (GLP)-1: In human research, capsaicin increased GLP-1 levels (495).
  • GlycerolGlycerol: In human research, capsaicinoid beadlets increased blood levels of glycerol (494).
  • Heart rateHeart rate: In humans, regular chili ingestion decreased resting heart rate (496).
  • InsulinInsulin: In humans and animals, capsaicin increased plasma insulin (49; 181; 182; 50).
  • IronIron: In humans, chili pepper reduced iron availability (478).
  • LactateLactate: In long-distance male runners, pungent Capsicum increased blood lactate levels at rest and during exercise (406).
  • LeptinLeptin: In human research, capsaicin, as part of a product also containing raspberry ketone, caffeine, garlic, ginger and Citrus aurantium (Prograde MetabolismT) resulted in an increase in serum leptin levels (426).
  • Lipid profileLipid profile: In animals, Capsicum was shown to reduce cholesterol levels (400). In humans, the carotenoid capsanthin, a constituent of Capsicum annuum, resulted in increases in plasma HDL cholesterol and had a lack of an effect on plasma total cholesterol and triglyceride concentrations (497). In animal research, capsaicin reduced LDL cholesterol, increased HDL cholesterol levels, decreased total cholesterol, increased and decreased and triglyceride levels (498; 246). In human research, use of a fermented red pepper paste as part of a combination product had lipid lowering effects (77).
  • Lipoprotein oxidationLipoprotein oxidation: In humans and in vitro, consumption of cayenne chili decreased the rate of oxidation and increased lag time to lipoprotein oxidation (48; 462; 463).
  • Liver function testsLiver function tests: In animal research, increased hot pepper intake resulted in inhibition and decreased levels of serum glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), alkaline phosphatase, and total bilirubin (499; 498; 246).
  • Subendocardial-viability ratio (SEVR)Subendocardial-viability ratio (SEVR): In humans, regular chili ingestion increased SEVR in men (496).