- Red peppers
- African chilies
- Tabasco peppers
- Mexican chilies
- Louisiana long pepper
For Patients & Caregivers
How It Works
Oral cayenne may provide limited relief of mucositis pain caused by radiation treatment, but it may cause gastric side effects in certain concentrations.
The capsicum pepper contains a chemical called capsaicin that is a powerful irritant. Because this compound can affect nerves that report painful stimuli to the brain, it has become useful in some forms such as over-the-counter creams for some skin conditions and nerve pain (See Capsaicin topical formulations). Oral forms have been marketed for circulation problems, poor appetite, and weight loss, but there are no studies to confirm such effects. It may be helpful for pain from mucositis caused by cancer therapy, but the study had a very small number of patients enrolled and effects were incomplete and temporary.
To treat gastrointestinal issues, improve appetite or digestion
Although capsaicin has been traditionally used for digestive issues, research is lacking. Also, the capsicum pepper is a known GI stimulant and irritant, and in certain amounts may actually cause diarrhea.
To improve circulation
Although cayenne is traditionally used for circulation, clinical trial data are lacking.
To manage type 2 diabetes
Limited data suggest capsaicin may help maintain insulin levels and lower blood glucose levels, but further study is needed.
To treat oral inflammation
A small study shows limited benefit to treat mucositis pain from cancer therapy. In addition, significant GI side effects occurred in a pilot study of patients with burning mouth syndrome.
For weight management
Any effect of capsaicin on weight management appears to be small.
Do Not Take If
- You are taking immunosuppressants: Capsaicin may increase its bioavailability or cause toxicities.
- You are taking blood pressure medications: Capsaicin may lessen its effects. It may also increase incidence of cough associated with ACE inhibitors.
- You are taking blood-thinning medications: Animal studies suggest capsaicin may have antiplatelet effects. Clinical relevance has yet to be determined.
- You are taking P-gp substrate drugs: Animal studies suggest capsaicin may affect how these drugs are absorbed or metabolized. Clinical relevance has yet to be determined.
- You are taking CYP450 3A substrate drugs: Animal studies suggest capsaicin may affect how these drugs are absorbed or metabolized. Clinical relevance has yet to be determined.
- You are taking theophylline: Animal studies suggest capsaicin may increase its absorption. Clinical relevance has yet to be determined.
- You are taking other prescription drugs: Capsaicin may interfere with their absorption.
- You have poorly controlled blood pressure, heart disease, or other vascular conditions.
- You are pregnant or breastfeeding: May cause skin redness in nursing babies.
- Sweating, flushing
- Eye/nose irritation
- GI irritation, pain
- Increased blood pressure
- High blood pressure: In two men after they ate large amounts of chili peppers.
- Gastric irritation, bleeding: After dietary intakes of capsicum in healthy volunteers.
- Skin rash/redness: In two infants shortly after breastfeeding by mothers who ate food spiced with red pepper.
For Healthcare Professionals
Derived from the fruit of Capsicum, cayenne is among the most widely consumed culinary spice. Traditionally, it is used as a gargle for laryngitis and orally as a gastrointestinal stimulant. Oral formulations are marketed largely for digestive and circulatory problems, poor appetite, and weight loss. The active component, capsaicin, is also marketed for topical use to relieve various types of pain and for certain skin conditions (See Capsaicin topical formulations).
Capsaicin may increase insulin and decrease blood glucose levels (1). Nonpungent capsaicin analogues can produce a stimulatory effect in humans, but their potential role in energy expenditure and weight management problems needs further clarification (2) (3) (4). In addition, the thermogenic and appetitive effects of capsaicin have been determined to be small (5). Oral capsaicin administered to participants in one study enhanced salty taste sensations, thereby lowering daily salt intake and subsequent blood pressure (29). A preliminary study of enteric-coated oral capsaicin suggests it may decrease visceral hyperalgesia and improve bloating in patients with irritable bowel syndrome (6), but supplementation with capsicum for burning mouth syndrome was associated with significant GI side effects (7).
Another study of oral capsaicin suggests it can alleviate oral mucositis pain from cancer therapy, but this relief was temporary and not complete (8). There is continued controversy over whether active constituents of capsicum act as a carcinogen, co-carcinogen, or anti-carcinogen (9) (10) (11) (12) , and effects may be concentration-dependent (9). In vitro studies have shown cytotoxic effects against breast (13), bladder (14), prostate (15), and oral cancer cell lines (16), and multidrug-resistant lymphoma (17). However, a human case-control study suggests an increased risk for gastric cancer with dietary capsaicin (18). Therefore, more studies are needed to clarify the roles of capsaicin in relationship to cancer.
Mechanism of Action
Capsaicin is the compound responsible for the irritant effects of capsicum (10). Perceived heat from capsaicin when ingesting cayenne is caused by activation of transient receptor potential vanilloid subfamily member 1 (TRPV1), located in neurons on the tongue (4). Capsinoids lack this sensory quality because they are hydrolyzed as they cross the oral mucosa (4). Potential thermogenic effects also involve TRPV1-receptor activation on vagal afferents in the gut (4). Capsaicin may induce energy expenditure by enhancing core body and skin temperature and influencing substrate oxidation, but these effects can vary with body composition (3) (5). In response to high-salt stimuli, oral capsaicin administration enhanced insula and orbitofrontal cortex (OFC) metabolic activity in participants, reversing salt intensity-dependent differences in the metabolism of the insula and OFC (29).
Vasodilator effects are attributed to the release of calcitonin gene-related peptide (CGRP). Depletion in CGRP leads to a subsequent increase in blood pressure (21). Interactions between capsaicin and cyclosporin suggest modulation of P-gp and CYP3A gene expression and increased cyclosporin bioavailability via CYP3A inhibition (22). Lignan glycosides isolated from capsicum pepper appear to have strong scavenging activity against free radicals (20).
In vitro and animal studies suggest capsaicin causes cell-cycle arrest and apoptosis in both ER+ and ER− breast cancer cells by modulating the EGFR/HER-2 pathway (13). Orally administered capsaicin slowed prostate cancer cell growth by downregulating androgen receptor expression and inhibiting PSA transcription (15). In bladder cancer, capsaicin mediates cell death through ROS production and mitochondrial depolarization (14). Conversely in certain concentrations, capsaicin may promote colorectal metastasis by triggering ROS production and modulating Akt/mTOR and STAT-3 pathways (9).
Common (oral): GI irritation, referred gastric pain (7).
Hypertension: Reported in two men following ingestion of large amounts of chili peppers (21) (24).
Gastric cell exfoliation, bleeding: Ingestion of dietary capsicum in healthy volunteers caused gastric cell exfoliation and bleeding (25).
Erythematous dermatitis: In two infants shortly after breastfeeding from mothers who had ingested food flavored with red pepper (23).
- Immunosuppressants (cyclosporin): Concurrent capsaicin should be avoided in transplant patients to minimize risk of kidney or liver toxicities as well as neurotoxicity. In animal models, chronic high-dose capsaicin use increased cyclosporin bioavailability (22).
- Antihypertensives: Capsaicin may affect their actions (21) or increase incidence of cough associated with ACE inhibitors (26).
- Antiplatelet drugs: Animal models indicate capsaicin has antiplatelet effects (27). Clinical relevance has yet to be determined.
- CYP450 3A substrates: Animal models indicate capsaicin may alter drug absorption and metabolism (22). Clinical relevance has yet to be determined.
- P-gp substrates: Animal models indicate capsaicin may alter drug absorption and metabolism (22).Clinical relevance has yet to be determined.
- Theophylline: Animal models indicate that concurrent capsaicin administration may increase absorption (28). Clinical relevance has yet to be determined.
- Oral coadministration of other drugs: Capsaicin causes mucosal vasodilation, and may thereby alter the uptake of other drugs (22).