Capsicum frutescens, Capsicum annuum
The capsicum family includes red peppers, bell peppers, pimento, and paprika, but the most famous medicinal member of this family is the common cayenne pepper.
Cayenne and related peppers have a long history of use as digestive aids in many parts of the world, but the herb's recent popularity has, surprisingly, come through conventional medicine.
What Is Cayenne Used for Today?
Many people think that hot peppers cause inflammation to tissues, and that this is the source of the classic hot pepper sensation. However, hot peppers don’t actually have any damaging effect; they merely simulate the sensations produced by damage. (Herbs like garlic, ginger, horseradish, and mustard actually can cause tissue damage.)
Here’s how it works: All hot peppers contain a substance called capsaicin. When applied to tissues, capsaicin causes release of a chemical called substance P. Substance P is ordinarily released when tissues are damaged; it is part of the system the body uses to detect injury. When hot peppers artificially release substance P, they trick the nervous system into thinking that an injury has occurred. The result: a sensation of burning pain.
When capsaicin is applied regularly to a part of the body, substance P becomes depleted in that location. This is why individuals who consume a lot of hot peppers gradually build up a tolerance.
It’s also the basis for a number of medical uses of capsaicin. When levels of substance P are reduced in an area, all pain in that area is somewhat reduced. Because of this effect, capsaicin cream is widely used for the treatment of various painful conditions.
Under the brand name Zostrix, a cream containing concentrated capsaicin has been approved by the FDA for the treatment of post-herpetic neuralgia, the pain that often lingers after an attack of shingles. There is also relatively good evidence that topical capsaicin can modestly decrease the pain of diabetic peripheral neuropathy, other forms of peripheral neuropathy nerve pain following cancer surgery, as well as the pain of arthritis. Capsaicin cream may also be helpful for other forms of pain, including fibromyalgia, back pain, and cluster headaches.1,2,3,4 However, the benefits seen with capsaicin are seldom dramatic; in many cases, other pain relieving treatments are used simultaneously.
Besides pain-related conditions, some evidence indicates that topical capsaicin may be helpful for psoriasis and possibly other skin conditions as well (especially those that involve itching).
Cayenne can be taken internally as well. It appears that oral use of cayenne might reduce the pain of minor indigestion ( dyspepsia). This may seem like an odd use of the herb; intuitively, it seems that hot peppers should be hard on the stomach. However, remember that hot peppers don’t actually damage tissues—they merely produce sensations similar to those caused by actual damage. Apparently, by depleting substance P in the stomach, they reduce sensations of discomfort. In fact, some evidence suggests that oral use of cayenne or capsaicin can actually protect the stomach against ulcers caused by anti-inflammatory drugs .5,6,7 However, contrary to some reports, cayenne does not appear to be able to kill Helicobacter pylori, the stomach bacteria implicated as a major cause of ulcers.9
What is the Scientific Evidence for Cayenne?
Oral Uses of Cayenne
In a double-blind, placebo-controlled study, 30 individuals with dyspepsia were given either 2.5 g daily of red pepper powder (divided up and taken prior to meals) or placebo for 5 weeks.13 By the third week of treatment, individuals taking red pepper were experiencing significant improvements in pain, bloating, and nausea as compared to placebo, and these relative improvements lasted through the end of the study.
Topical Uses of Cayenne
All double-blind studies of topical capsaicin (or cayenne) suffer from one drawback: It isn’t really possible to hide the burning sensation that occurs during initial use of the treatment. For this reason, such studies probably aren’t truly double-blind. It has been suggested that instead of an inactive placebo, researchers should use some other substance (such as camphor) that causes at least mild burning. However, such treatments might also have therapeutic benefits; they have a long history of use for pain as well.
Because of these complications, the evidence for topical treatments cited below is less meaningful than it might at first appear.
Capsaicin cream is well established as a modestly helpful pain-relieving treatment for:
In a review of six randomized trials of 2,073 adults with postherpetic neuralgia or HIV-associated neuropathy, a high-dose capsaicin (8%) patch significantly improved pain symptoms for up to 12 weeks compared to a low-dose (0.04%) capsaicin patch.42
Supportive evidence also exists for the use of topical capsaicin for soft tissue pain (muscles, tendons, and ligaments)40 and pain following hernia repair.36 Weak evidence supports its use for fibromyalgia.4
Topical capsicum-based cream was associated with reduced acute low back pain compared to placebo in a small randomized trial with 40 adults.43 Actual cayenne rather than capsaicin has been tested for pain, as well. A 3-week, double-blind trial of 154 individuals with back pain found that cayenne applied topically as a “plaster” improved pain to a greater extent than placebo.30
A double-blind, placebo-controlled trial of nearly 200 individuals found that use of topical capsaicin can improve itching as well as overall severity of psoriasis.31 Benefits were also seen in a smaller double-blind study of topical capsaicin for psoriasis.32
Intranasal Uses of Cayenne for Rhinitis
One study of 208 patients with idiopathic (unknown cause) rhinitis found that using a capsicum nasal spray 3 times daily for 3 days (4 mcg/puff) may reduce symptom frequency.38 And, a small randomized, placebo-controlled trial involving 42 people with nonallergic rhinitis found that an intranasal product called Sinus Buster (a combination of cayenne and eucalyptus) used twice daily for 2 weeks helped to improve sinus congestion, pain, pressure, and headache.41
Capsaicin creams are approved over-the-counter drugs and should be used as directed. If the burning sensation that occurs with initial use is too severe, using weaker forms of the cream at first may be advisable.
For treatment of dyspepsia, cayenne may be taken at a dosage of 0.5 to 1.0 g three times daily (prior to meals).
Capsaicin creams commonly cause an unpleasant burning sensation when they are first applied; this sensation disappears over subsequent days as treatment is continued.
1. McCleane G. Topical application of doxepin hydrochloride, capsaicin and a combination of both produces analgesia in chronic human neuropathic pain: a randomized, double-blind, placebo-controlled study. Br J Clin Pharmacol. 2000;49:574-579.
2. Deal CL, Schnitzer TJ, Lipstein E, et al. Treatment of arthritis with topical capsaicin: A double blind trial. Clin Ther. 1991;13:383-395.
3. McCarthy GM, McCarty DJ. Effect of topical capsaicin in the therapy of painful osteoarthritis of the hands. J Rheumatol. 1992;19:604-607.
4. McCarty DJ, Csuka M, McCarthy, et al. Treatment of pain due to fibromyalgia with topical capsaicin: A pilot study. Semin Arthritis Rheum. 1994;23(suppl 3):41-47.
5. Yeoh KG, Kang JY, Yap I, et al. Chili protects against aspirin-induced gastroduodenal mucosal injury in humans. Dig Dis Sci. 1995;40:580-583.
6. Abdel Salam OM, Moszik G, Szolcsanyi J. Studies on the effect of intragastric capsaicin on gastric ulcer and on the prostacyclin-induced cytoprotection in rats. Pharmacol Res. 1995;32:209-215.
7. Holzer P, Pabst MA, Lippe IT. Intragastric capsaicin protects against aspirin-induced lesion formation and bleeding in the rat gastric mucosa. Gastroenterology. 1989;96:1425-1433.
8. Stander S, Luger T, Metze D. Treatment of prurigo nodularis with topical capsaicin. J Am Acad Dermatol. 2001;44:471-478.
9. Graham DY, Anderson SY, Lang T. Garlic or jalapeno peppers for treatment of Helicobacter pylori infection. Am J Gastroenterol. 1999;94:1200-1202.
10. Rodriguez-Stanley S, Collings KL, Robinson M, et al. The effects of capsaicin on reflux, gastric emptying and dyspepsia. Aliment Pharmacol Ther. 2000;14:129-134.
11. Graham DY, Smith JL, Opekun AR. Spicy food and the stomach. Evaluation by videoendoscopy. JAMA. 1988;260:3473-3475.
12. Bouraoui A, Toumi A, Mustapha HB, et al. Effects of capsicum fruit on theophylline absorption and bioavailability in rabbits. Drug Nutr Interact. 1998;5:345-350.
13. Bortolotti M, Coccia G, Grossi G, et al. The treatment of functional dyspepsia with red pepper. Aliment Pharmacol Ther. 2002;16:1075-1082.
14. Watson CP, Evans RJ, Watt VR. Post-herpetic neuralgia and topical capsaicin. Pain.1988;33:333-340.
15. Watson CP, Tyler KL, Bickers DR, et al. A randomized vehicle-controlled trial of topical capsaicin in the treatment of postherpetic neuralgia. Clin Ther. 1993;15:510-526.
16. Alper BS, Lewis PR. Treatment of postherpetic neuralgia: a systematic review of the literature. J Fam Pract. 2002;51:121-128.
17. Low PA, Opfer-Gehrking TL, Dyck PJ, et al. Double-blind, placebo-controlled study of the application of capsaicin cream in chronic distal painful polyneuropathy. Pain. 1995;62:163-168.
18. Biesbroeck R, Bril V, Hollander P, et al. A double-blind comparison of topical capsaicin and oral amitriptyline in painful diabetic neuropathy. Adv Ther. 1995;12:111-120.
19. The Capsaicin Study Group. Effect of treatment with capsaicin on daily activities of patients with painful diabetic neuropathy. Diabetes Care. 1992;15:159-165.
20. Tandan R, Lewis GA, Krusinski PB, Badger GB, Fries TJ. Related Articles Topical capsaicin in painful diabetic neuropathy. Controlled study with long-term follow-up. Diabetes Care. 1992;15:8-14.
21. The Capsaicin Study Group. Treatment of painful diabetic neuropathy with topical capsaicin. A multicenter, double-blind, vehicle-controlled study. Arch Intern Med. 1991;151:2225-2229.
22. Scheffler NM, Sheitel PL, Lipton MN. Related Articles Treatment of painful diabetic neuropathy with capsaicin 0.075%. J Am Podiatr Med Assoc. 1991; 81:288-293.
23. Jensen PG, Larson JR. Management of painful diabetic neuropathy. Drugs Aging. 2001;18:737-749.
24. Ellison N, Loprinzi CL, Kugler J, et al. Phase III placebo-controlled trial of capsaicin cream in the management of surgical neuropathic pain in cancer patients. J Clin Oncol. 1997;15:2974-2980.
25. Dini D, Bertelli G, Gozza A, et al. Treatment of the post-mastectomy pain syndrome with topical capsaicin. Pain. 1993;54:223-226.
26. Watson CP, Evans RJ. The postmastectomy pain syndrome and topical capsaicin: a randomized trial. Pain. 1992;51:375-379.
27. Watson CP, Evans RJ, Watt VR, et al. The post-mastectomy pain syndrome and the effect of topical capsaicin. Pain. 1989;38:177-186.
28. Todd C. Meeting the therapeutic challenge of the patient with osteoarthritis. J Am Pharm Assoc (Wash). 2002;42:74-82.
29. Marks DR, Rapoport A, Padla D, et al. A double-blind placebo-controlled trial of intranasal capsaicin for cluster headache. Cephalalgia. 1993;13:114-116.
30. Frerick H, Keitel W, Kuhn U, et al. Topical treatment of chronic low back pain with a capsicum plaster. Pain. 2003;106:59-64.
31. Ellis CN, Berberian B, Sulica VI, et al. A double-blind evaluation of topical capsaicin in pruritic psoriasis. J Am Acad Dermatol. 1993;29:438-442.
32. Bernstein JE, Parish LC, Rapaport M, et al. Effects of topically applied capsaicin on moderate and severe psoriasis vulgaris. J Am Acad Dermatol. 1986;15:504-507.
33. Reimann S, Luger T, Metze D. Topical administration of capsaicin in dermatology for treatment of itching and pain. Hautarzt. 2000;51:164-172.
34. Altomare DF, Rinaldi M, La Torre F, et al. Red Hot Chili Pepper and Hemorrhoids: The Explosion of a Myth: Results of a Prospective, Randomized Placebo-Controlled Crossover Trial. Dis Colon Rectum. 2006 May 19. [Epub ahead of print]
35. Simpson DM, Brown S, Tobias J. Controlled trial of high-concentration capsaicin patch for treatment of painful HIV neuropathy. Neurology. 2008;70:2305-2313.
36. Aasvang EK, Hansen JB, Malmstrom J, et al. The effect of wound instillation of a novel purified capsaicin formulation on postherniotomy pain: a double-blind, randomized, placebo-controlled study. Anesth Analg. 2008;107:282-291.
37. Backonja M, Wallace MS, Blonsky ER, et al. NGX-4010, a high-concentration capsaicin patch, for the treatment of postherpetic neuralgia: a randomised, double-blind study. Lancet Neurol. 2008;7:1106-1112.
38. Ciabatti PG, D'Ascanio L. Intranasal Capsicum spray in idiopathic rhinitis: a randomized prospective application regimen trial. Acta Otolaryngol. 2009;129:367-71.
39. De Silva V, El-Metwally A, Ernst E, Lewith G, Macfarlane GJ. Evidence for the efficacy of complementary and alternative medicines in the management of osteoarthritis: a systematic review. Rheumatology. 2010 Dec 17.
40. Chrubasik S, Weiser T, Beime B. Effectiveness and safety of topical capsaicin cream in the treatment of chronic soft tissue pain. Phytother Res. 2010;24(12):1877-1885.
41. Bernstein JA, Davis BP, Picard JK, Cooper JP, Zheng S, Levin LS. A randomized, double-blind, parallel trial comparing capsaicin nasal spray with placebo in subjects with a significant component of nonallergic rhinitis. Ann Allergy Asthma Immunol. 2011;107(2):171-178.
42. Irving G, Backonja M, et al. NGX-4010, a capsaicin 8% dermal patch, administered alone or in combination with systemic neuropathic pain medications, reduces pain in patients with postherpetic neuralgia. Clin J Pain. 2012;28(2):101-107.
43. Oltean H, Robbins C, et al. Herbal medicine for low-back pain. Cochrane Database Syst Rev. 2014;12:CD004504.
Last reviewed December 2015 by EBSCO CAM Review Board
Last Updated: 12/15/2015
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