- red peppers
- hot peppers
- African chilies
- tabasco peppers
- Mexican chilies
- Louisiana long pepper
For Patients & Caregivers
Bottom Line: 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. 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 relieve colic and stomach/intestinal gas
No scientific evidence supports this use. The capsicum pepper is known to be a gastrointestinal stimulant and irritant.
- To treat diarrhea
This claim is not backed by data. In certain amounts, it may actually cause diarrhea.
- To treat headaches
Laboratory data show that capsaicin blocks pain fibers, but whether it can treat headaches is unknown.
- To lower high cholesterol
No scientific evidence supports this use.
- To manage type 2 diabetes
Capsaicin may help to maintain insulin levels and lower blood glucose levels. Further study is needed.
- To improve circulation
Although cayenne is traditionally used for circulation, clinical trial data are lacking.
- To treat burning mouth syndrome
A pilot study showed benefit, however, significant side effects were also noted.
- To treat oral inflammation
A small study shows limited benefit to treat mucositis pain from cancer therapy.
- To treat stomach and intestinal gas
Although capsaicin has traditionally been used for digestive issues, research is lacking.
- Weight management
Any effect of capsaicin on weight management appears to be small.
Type 2 diabetes
A small study suggests that cayenne may decrease blood glucose levels and maintain insulin levels, but large-scale clinical trials are needed to confirm such observations.
In reviewing 234 cases of gastric cancer in Mexico, a study found that high intake of chili peppers (about 9–25 jalapeno peppers daily) was linked to an increased risk of gastric cancer.
Capsaicin in a taffy candy was given to 11 patients with oral mucositis pain from cancer therapy. Limited, temporary relief was provided by the therapy. Further study is warranted.
- You are taking ACE inhibitors: Can increase the incidence of cough that is associated with ACE inhibitors.
- You are taking blood-thinning medications: Capsaicin may have antiplatelet effects.
- You are taking blood pressure medications: Capsaicin may lessen its effects.
- You are taking immunosuppressants: Capsaicin may increase its bioavailability.
- You are taking drugs that are substrates of P-glycoprotein: Capsaicin may affect how these drugs are absorbed or metabolized.
- You are taking drugs that are substrates of Cytochrome P450 3A: Capsaicin may affect how these drugs are absorbed or metabolized.
- You are taking theophylline: Capsaicin may increase its absorption.
- 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 and flushing, irritation of the eyes and nose. In large doses, capsicum can cause irritation of the gastrointestinal tract or increase blood pressure.
- High blood pressure in two men after they ate large amounts of chili peppers.
- Gastric cell exfoliations and bleeding after dietary intakes of capsicum in healthy volunteers.
- Skin rash/redness in two infants shortly after being breastfed 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 also 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). A preliminary study of enteric-coated oral capsaicin suggests it may decrease visceral hyperalgesia and improve bloating in patients with irritable bowel syndrome (6). Supplementation with capsicum for burning mouth syndrome is associated with significant side effects (7). Another study of oral capsaicin in a candy 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.
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 activation of TRPV1 receptors 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). It was also found to induce coronary vasodilation by releasing calcitonin gene-related peptide (CGRP), a potent vasodilator. Depletion in CGRP leads to a subsequent increase in blood pressure (21). Interactions between capsaicin and cyclosporin indicate the ability of capsaicin to modulate P-gp and CYP3A gene expression and to also increase cyclosporin bioavailability via CYP3A inhibition (22). Lignan glycosides isolated from capsicum pepper were also shown to have strong scavenging activity against the free radical, DPPH (20). In vitro and animal studies indicate 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 also slowed the growth of PC-3 prostate cancer cells in mice by downregulating expression of androgen receptors and by a direct inhibitory effect on prostate specific antigen transcription (15). In bladder cancer, capsaicin mediates cell death through reactive oxygen species (ROS) production and mitochondrial depolarization (14). Conversely, in certain concentrations, capsaicin may promote colorectal cancer metastasis by triggering ROS production and modulating Akt/mTOR and STAT-3 pathways (9).
In 12 healthy volunteers, after ingestion of fresh capsicum 5g (capsaicin 26.6 mg), capsaicin was detected in the plasma at 10 minutes, with peak plasma concentration of 2.47 ± 0.13 ng/mL (Tmax, 47.08 ± 1.99 minutes). Capsaicin absorption AUC0–t was 103.6 ± 11.3 ng.min/mL (1).
Common (oral): GI irritation, referred gastric pain (7).
Arterial hypertension: Reported in two men following ingestion of large amounts of chili peppers (21)(24).
Gastric cell exfoliation and bleeding: Ingestion of dietary capsicum in healthy volunteers caused gastric cell exfoliation and bleeding (25).
Erythematous dermatitis: Reported in two infants shortly after breastfeeding from mothers who had ingested food flavored with red pepper (23).
ACE inhibitors: Capsaicin may increase the incidence of cough associated with ACE inhibitors (26).
Antihypertensives: Capsaicin may affect their actions (21).
Antiplatelet drugs: Animal models indicate capsaicin has antiplatelet effects (27).
Cytochrome P450 (CYP) 3A substrates: Capsaicin may alter drug absorption and metabolism (22). Immunosuppressants (cyclosporin): Concurrent capsaicin should be avoided for transplant patients in order to minimize the risk for nephrotoxicity, hepatotoxicity and neurotoxicity. In animal models, chronic high-dose capsaicin use increased cyclosporin bioavailability (22).
P-glycoprotein (P-gp) substrates: Capsaicin may alter drug absorption and metabolism (22).
Theophylline: Animal models indicate that concurrent capsaicin administration may increase absorption (28).
Oral co-administration of other drugs: Capsaicin causes mucosal vasodilation, thereby altering the uptake of other drugs (22).
Chalyasit K, et al. Pharmacokinetic and the effect of capsaicin in Capsicum frutescens on decreasing plasma glucose level. J Med Assoc Thai. 2009 Jan;92(1):108-13.
A placebo-controlled, crossover study was conducted to determine the effect of capsaicin on plasma insulin and blood glucose levels. This study enrolled 12 healthy volunteers who received a single dose of either placebo or capsicum 5g. After a 1-week washout period, subjects crossed over to receive the other treatment. Insulin secretion and capsaicin levels in plasma were measured using an HPLC method. Results of an oral glucose tolerance test demonstrated that in subjects who had received capsicum, plasma glucose levels were significantly lower at 30 and 45 minutes (P<.05), and plasma insulin levels were significantly higher at 60, 75, 105, and 120 minutes (P<.05), than for those in the placebo group. Ingestion of capsicum 5g was therefore associated with decreased plasma glucose levels and the maintenance of insulin levels. The authors concluded that these study results may have clinical implications for the management of type 2 diabetes.
Lopez-Carrillo L, et al. Capsaicin consumption, Helicobacter pylori positivity and gastric cancer in Mexico. Int J Cancer. 2003;106:277-282.
Chili pepper intake was evaluated in this case control study to assess whether capsaicin (CAP) intake increased gastric cancer (GC) risk independently of H. pylori (Hp) positivity. From 1994 to 1996, 234 cases of GC and 468 matched controls in 3 areas of Mexico were enrolled. Chili pepper intake was queried by interview. CAP amount in chilies was determined in a separate analysis by gas chromatography to estimate intake; IgG Hp serum antibodies were determined by ELISA. GC risk increased (OR=1.71; 95% CI=0.76–3.88) among high-level vs low-level CAP consumers: 90–250 mg daily (~9–25 jalapeno peppers daily) vs 0–30 mg daily (<3 jalapeno peppers daily), respectively. This effect appeared to be independent of Hp status and other potential GC determinants, and was higher among diffuse GC cases (OR=3.64; 95% CI=1.09-12.2; P for trend=.002) compared with intestinal GC cases (OR=1.36; 95% CI = 0.31-5.89; P for trend=.493). No significant interaction was found between CAP intake and Hp on GC risk. The authors determined that levels of chili pepper consumption might be an independent determinant of GC.
Berger A, et al. Oral capsaicin provides temporary relief for oral mucositis pain secondary to chemotherapy/radiation therapy. J Pain Symptom Manage. 1995;10:243-248.
This older pilot study evaluated whether oral capsaicin in the form of a cayenne pepper taffy candy could provide relief from oral mucositis pain caused by cancer therapy. Taffy was chosen as the delivery vehicle because it does not have sharp edges, which could exacerbate symptoms. At total of 11 patients were enrolled and had the option of full-strength (n=9) or half-strength formulations (n=2). Although patients experienced pain reduction, the relief experienced was not complete and was also temporary. Additional research is needed.