How does it feel?
Chilli is characterised by its unique hot, spicy pungent qualities. The heat or spice element of chilli varies for each specific variety. Once the initial hot sensation settles on the taste buds chillies fruity and sour taste sensations shine through.
The tincture of chilli is often used by herbalists in very small doses in formulas for internal use. Tinctures can be extremely powerful in their pungency. Even 2 drops drop in a 100ml formula can be detected.
The tincture is also often used in small quantities mixed into ointments or liniments for topical use for pain management. Used topically, chilli has powerful analgesic effects.
What can I use it for?
The capsicum genus comprises a number of different subspecies, varieties and cultivars. The most readily available are chilli peppers, bell peppers and jalapeño peppers. All of the varieties of hot or spicy chillies have many benefits for systemic health.
Regular intake of foods containing chilli spice or fresh chilli can have a number of therapeutic effects on the digestive, cardiovascular and respiratory systems.
Chilli is one of the most useful of the stimulating diaphoretic herbs (a herb that stimulates the sweat reflex). Its potent diaphoretic action makes it useful to help bring out or ‘break’ a fever making it a useful tonic to help the body’s natural defences against infections and also for general body cleansing as it promotes circulation and movement between the blood and the tissues.
Chilli is also useful for alleviating symptoms of various respiratory problems such as coughs, colds and sinus infections. It can help reduce inflammation, improve blood flow, and relieve congestion in the upper respiratory tract and may be useful for conditions such as rhinitis and allergic airway inflammation.
As a carminative, chilli is also used in flatulence, dyspepsia and colic. It is also a powerful circulatory stimulant and it will increase blood supply to the digestive organs, hence it enhances their activities (secretions and regular contractions) and metabolism of nutrients.
Chilli also produces many beneficial effects on the cardiovascular system. It acts as a cardiac tonic that can improve cardiac circulation- strengthening the heart, arteries and capillaries. Chilli also improves peripheral circulation to the hands and feet making them an excellent dietary tonic for those who suffer from cold extremities.
If one wants to work with chilli at home to treat mild digestive issues, acute infections or for digestive support – regular or daily dietary intake of dried or fresh chilli is sufficient for these purposes.
Into the heart of Chilli Peppers
Chilli is classified energetically as a warming stimulant. It is hot in the 3rd degree- making it one of the hottest of herbs. This heating action is really best understood by the plant’s ability to support increased circulation and tissue perfusion. Chilli is a vasodilator (dilates the blood vessels) and therefore increases the movement of blood between the capillaries and the tissues around the body. Because of this systemic circulatory action, it affects nearly every organ system in the body.
It works best for conditions where there is a cold and depressed tissue state. ‘Coldness’, as referenced in Western herbal energetics- refers to a lack of physiological vitality or lack of warmth and perfusion to the tissues. ‘Depressed’ refers to a lack of or reduced function.
A cold, depressed tissue state will likely be indicated where there is a pale complexion along with darkness around the eyes, cold extremities and cold skin. They will often have low resilience to infections. Depressed tissue states will sometimes present with imbalances in the microbiome due to a lack of integrity in the digestive mucosa. Where the system is in a depressed or poor state of function there will likely also be signs of congestion, excess of mucous and infective secretions as a result of poor mucosal tone.
The stimulating aromatic qualities of chilli allow for better tissue function due to its opening effect on the microcirculation and increased tissue perfusion. This includes the periphery and also the mucous membranes that line our internal organs. Aromatic herbs play an important role in re-energising the tissues. Improving the movement of blood brings warmth and vitality. These herbs can be invaluable for treating cold and depressed tissue conditions (9).
Herbalists will often pay close attention to the condition of the tissues i.e. inflammation (heat), coldness (depressed function) rather than specific diagnoses. Many diagnosable conditions say a lot more about the systemic health of the tissues and how the tissues are responding to factors such as environmental factors and stress. What is often found is that tissue disorder is found throughout the body and is not just localised i.e. a migraine patient will likely have constriction and tension in other parts of the body.
A herbalist understands that the body is a self-correcting system and that imbalances or diseases occur when there is a disparity within the body that has a cause. When it comes to chronic illness- patients will often have a number of ‘conditions’, diagnoses or symptoms that are seemingly unrelated. However, upon assessment of the tissue state – a herbalist will be able to identify the root causes of these problematic physiological patterns. A herbalist will likely use both herbs and nutrition to nudge the system back towards balanced physiological function.
Chilli is native to central and south America. Their medicinal and culinary use by Native Americans as food and medicine has been documented for at least nine thousand years.
Based on archaeological evidence, its cultivation in Mexico is believed to have begun around seven thousand years ago. Chilli was introduced into traditional Indian Ayurvedic medicine as well as traditional Chinese medicine (TCM), Japanese, and Korean medicines, respectively.
In TCM, cayenne is considered to have digestive stimulant action and is sometimes used to stimulate diaphoresis. In China and Japan, the tincture is used as an ointment externally to treat muscle pain and frostbite.
What practitioners say
Chilli is known as some of the most powerful pungent, circulatory stimulants in the materia medica. A renowned herbalist Simon Mills discusses their therapeutic actions in his book ‘The Essential Book of Herbal Medicine’ in which he states that chillies ‘influence is permanent and reaches every organ through its primary influence upon the circulation’ (10).
Chilli is used in very small doses usually as part of a prescription for internal use. Herbalists will often include stimulating aromatic herbs as part of a prescription to assist in the vigorous circulation and deliverance of other herbs and their active constituents to the tissues where they are needed. This classification of aromatic stimulants may be described as carrier remedies- they support and potentiate the effects of other herbs.
These aromatic herbs are invaluable as part of any prescription. However, chilli is not the best remedy for gentle effects and is best used where there is a more immediate or intense need to bring ‘vital heat’ to the body such as where there is deeply ‘cold’, congested and cyanotic tissues often associated with severely compromised circulation (10).
Chilli is used in herbal medicine both internally and externally for pain management. A compound found in chilli called capsaicin acts upon the sensory neurons and pain transmitters to elicit an analgesic action. Capcaicin also stimulates the hypothalamus to reduce core body temperature (2) thus explaining how it is able to help regulate the temperature in fever management.
Capsaicin blocks the transmission of pain and itching via a mechanism of nerve fibres in the skin. It works by depleting local supplies of a neurotransmitter called substance P which is involved in transmitting pain and itching signals from the nerves to the central nervous system (2, 11).
A link exists between pain disorders and unusually high levels of substance P in nerve fibres. Chilli works selectively and does not block impulses to all of the nerve fibres. This means that it does not interfere with the perception of touch, temperature or pressure in the ways that other local anaesthetics sometimes do (11).
Chilli also allows for better cerebral circulation and may therefore be a valuable part of a formula for the treatment of depression- particularly when accompanied by a low libido. The warming and stimulating action of chilli improves circulation to the reproductive organs.
Liniments or ointments containing chilli extract are used topically to treat shingles (herpes zoster) and chronic post-herpetic neuralgia (5).
Chilli is both analgesic and antispasmodic making it a valuable herb for the internal and topical treatment of rheumatic conditions.
Internal use of chilli works in a number of dynamic ways to to help stimulate the movement of circulation to the periphery and also enhance perfusion into the muscular tissue. This allows for better detoxification of the muscle tissue whilst also delivering more oxygen and nutrients to them.
Chilli is often added into topical liniments or ointments to be used to alleviate various types of pain, including lower back pain, muscle pain (4) joint pain, and nerve pain. This may be applied in conditions such as carpal tunnel syndrome, rheumatism, neuralgia and sciatica (2).
Chilli is also sometimes used within a prescription for other rheumatic conditions such as rheumatoid arthritis (2). Its anti-spasmodic and analgesic actions combine to reduce nerve pain whilst also relaxing the musculature through a spasmolytic action.
One of the mechanisms by which chilli works is by reducing the amount of substance P (a neurotransmitter that is involved in pain perception) in the nerve tissue. Capsaicin, a key constituent in chilli can also help improve blood flow and reduce inflammation (6).
Chilli has many health-promoting effects for the circulatory system. One of its primary actions is as a vasodilator, meaning that it helps relax and open up the microcirculation. This may be one of the most appropriate herbal medicines to encourage healing in the tissues where circulation has led to tissue damage in the periphery (2).
It works by improving the blood flow, therefore enhancing tissue perfusion (1). It improves systemic circulation but also circulation within the heart as well as having many metabolic actions that can help to protect against heart disease.
Chilli is sometimes used in the treatment of heart conditions- particularly where the cardiac circulation is affected such as in angina (2). It is said to be one of the ‘most powerful and persistent heart stimulants known’- both increasing arterial force and frequency of heart rate (10).
It is however not suitable for those with severe high blood pressure or where there is systemic heat and inflammation as it is likely to aggravate the condition.
Chilli is used to promote digestive health and alleviate various digestive problems such as indigestion, bloating, and constipation. It can help stimulate the digestive system, improve digestion and reduce inflammation in the gastrointestinal tract (2).
It can effectively stimulate stomach acid secretion and mucosal function in the upper digestive tract. It also enhances gastric mucosal blood supply which may help in the prevention and healing of gastric ulcers (6). However- other texts state that chilli may not be problematic in the treatment of gastric ulcers and hyperacidity (10). It is best to consult a qualified medical herbalist for the effective and safe treatment of gastric ulcers and other more serious conditions as not all herbs are suitable for everyone.
Increasing stomach acid production also assists in the sterilising activity of the stomach against potential enteric infections (10). It is well known in tropical countries that pungent spices such as chilli can offer some protection against enteric infections.
Various studies also show that capsicum spp can improve microbiome health. You can read more about chilli and the microbiome, as well as other herbs for the gut in our article “Plants and the gut microbiome: Prebiotics and postbiotics“.
Chilli is also sometimes used as part of a treatment plan for weight loss and obesity. There are four primary areas of potential benefit for weight management which are thought to combine in effects. Chilli increases energy output, increases lipid oxidation and reduces appetite (7). It is also anticholesterolaemic and antiscletrotic (2). All of these factors help towards this well-studied application for chilli.
Chilli is sometimes recommended for use 1 hour before low-intensity exercise to improve the metabolism of fats which may be a useful element in a treatment protocol for patients with hyperlipidemia and/ or obesity. This is likely because chilli ingestion increases energy expenditure through the activation of brown adipose tissue (8).
Topically chilli is used as a rubefacient (counter-irritant) to increase circulation and aid in pain management such as for rheumatic pains. Its counter-irritant effect causes vasodilation (and heat) in whichever tissue it comes into contact (11).
Applied externally as a plaster, liniment or ointment it will produce a considerable counter-irritant effect. This works by a significant increase in sub-dermal circulation in the capillary beds in the area of treatment- which results in reduced inflammation and pain in the localised area whilst also assisting in healing (10).
An external preparation of chilli can also be used to treat some itchy skin disorders. The topical application of chilli is suitable for the pain and itching associated with shingles. It may also be used topically in the treatment of psoriasis (11) perhaps as part of an ointment in combination used alongside internal herbs that address systemic issues and inflammation. Psoriasis is best treated with a herbalist as it is a complex condition, and so systemic approaches are needed to focus on the root cause which will be unique to the patient.
There are some promising clinical trials on chilli as well as some insightful in vivo and in vitro studies that focus on a number of its compounds which demonstrate a variety of its effects. A number of these studies have been included below to demonstrate the mechanism of action for some of the medicinal actions of chilli discussed in this monograph.
Animal studies are not condoned by herbal reality, however for the purpose of including research from which some understanding of therapeutic actions can be confirmed, some animal studies have been included herein.
Cardiovascular health and other therapeutic effects of capsicum: A review
A review discusses a number of studies whose results demonstrate a range of therapeutic effects of capsicum and its constituents. Clinically, the ingestion of capsaicin-or its less stable non-pungent analogue capsiate has been shown to boost metabolic rate. This action is also associated with the metabolic of brown adipose tissue – raising metabolic rate.
Topical application of capsaicin via a dermal patch was found to increase exercise time to ischaemic threshold in patients with angina. In vivo studies show that capsaicin favourably impacts endothelium-dependent vasodilation. Capsaicin also promotes cholesterol export and antagonises plaque formation.
Other effects which may help in the understanding of chilli mechanism of action relate to its antioxidant and anti-inflammatory actions. This review also confirms that decreasing expression of pro-inflammatory proteins has been evidenced in research. These mechanisms may help in the understanding of chillies important potential for promoting vascular and metabolic health (13).
A succession of studies have been carried out starting from a small preliminary study size which led through to a number of larger studies to evaluate the effects of chilli and its constituents in the treatment of postherpetic and neuralgic pain.
A preliminary study was carried out to ascertain the effects of capsaicin on patients with postherpetic neuralgia. 14 patients with postherpetic neuralgia were given capsaicin as a topical application for painful areas of skin for a period of 4 weeks. 12 patients completed this preliminary study, 75% experienced substantial relief of their pain. The only adverse reaction was an intermittent, localized burning sensation experienced by one patient with the application of capsaicin. Although these results are preliminary, they suggest that topical application of capsaicin may provide a useful approach for alleviating postherpetic neuralgia and other syndromes characterized by severe localised pain (5).
In another double-blind study 32 elderly patients with chronic postherpetic neuralgia were treated with either capsaicin cream or a placebo for a 6-week period. The results showed a significantly greater relief in the capsaicin-treated group compared with placebo. After 6 weeks almost 80% of capsaicin-treated patients experienced relief from their chronic pain. The study suggests that topical capsaicin may be useful for initial management of postherpetic neuralgia (15).
A larger double-blind, placebo-controlled study of 143 patients with chronic postherpetic neuralgia was conducted. All efficacy variables including pain reduction and changes in pain severity showed significant improvements at nearly all time points throughout the study for the chilli group. In contrast, the group receiving placebo cream remained essentially unchanged.
The present study concludes that capsaicin 0.075% cream is a safe and effective treatment for the pain of postherpetic neuralgia (16).
A clinical review of biological activities of Capsicum annum
A review was carried out to assess the available studies on C. annum- an important variety of chilli. The review concludes that this species has a potential clinical value for use as a cardio protective, anti-lithogenic, anti-inflammatory, and analgesic. It also discusses the clinical relevance of C. anuum for its thermogenic influence, and beneficial effects on the gastrointestinal system as well as for weight loss.
The review also confirms the result of studies that have investigated capsaicinoid potential as agonists of capsaicin receptor (TRPV1) in pain relief as well as the involvement of neuropeptide Substance P, serotonin, and somatostatin in the pharmacological actions of capsaicin.
Topical application of capsaicin is proven to alleviate pain in arthritis, postoperative neuralgia, diabetic neuropathy and psoriasis. Toxicological studies documented also demonstrate capsaicin’s ability to inhibit acid secretion, stimulate alkali and mucus secretion and particularly gastric mucosal blood flow which may help in the prevention and healing of gastric ulcers.
Antioxidant and anti-inflammatory properties of capsaicin are established in a number of studies. Various cell line studies show the chemopreventive potential of capsaicin is also evidenced. The hypocholesterolemic influence of capsaicin besides being cardioprotective has other implications such as supporting the prevention of cholesterol gallstones and the protection of the structural integrity of erythrocytes under conditions of hypercholesterolemia.
Beneficial influences of capsaicin on the gastrointestinal system include digestive stimulant action and the modulation of intestinal ultrastructure so as to enhance permeability to micronutrients (6).
A systemic review of studies for the use of capsaicinoids in weight management
A systematic review of research investigating the potential benefits of capsaicinoids in relation to weight management was carried out. 90 trials were identified, 20 of which were selected for inclusion, involving a total of 563 participants.
Three main areas of potential benefit for weight management were found: (1) increased energy expenditure; (2) increased lipid oxidation and (3) reduced appetite.
The review confirms that consumption of capsaicinoids increases energy expenditure by approximately 50 kcal/day suggesting clinically significant levels of weight loss in 1-2 years.
It was also observed that regular consumption significantly reduced abdominal adipose tissue levels and reduced appetite and energy intake. The review concludes that the weight of evidence shows a positive potential for chilli as part of a weight management program (7).
A crossover, randomised, double blind study was carried out to determine the efficacy of capsaicin in desensitising the cough reflex and improving unexplained coughing. Twenty-four patients with irritant-induced, unexplained chronic cough and 15 control subjects were included in the study. Participants took capsules with pure capsaicin and the control group took a placebo capsule for a period of 4 weeks.
The cough symptom scores improved after 4 weeks of active treatment compared to the placebo group. The study concludes that capsaicin powder taken orally decreases cough sensitivity and cough symptoms (12).
Meta-analysis of studies associated with capsicum and capsaicin in relation to metabolic syndrome
In this meta-analysis numerous databases were searched to analyse the available studies on C. annuum supplementation and their effects on the components of metabolic syndrome in human subjects. 11 main studies were included with a total of 609 participants with results demonstrating that C. annuum had significant effects on low density lipoprotein-cholesterol (LDL cholesterol) and on body weight (13). Metabolic syndrome is the main risk factor for cardiovascular diseases and type II diabetes mellitus.
Gestational diabetes mellitus (GDM)
In a randomized, double-blind, placebo-controlled study was carried out to determine the effect of capsaicin supplementation on blood glucose, lipid metabolism and pregnancy outcomes in women with GDM. Forty-four pregnant women with GDM between 22-33 weeks pregnant were randomly assigned to the capsaicin group (5 mg a day of capsaicin) or to the placebo group for 4 weeks. The results showed that fasting serum total cholesterol and triglycerides concentrations significantly decreased in the capsaicin group after treatment compared to the placebo group. Moreover, the fasting serum apolipoprotein B and CGRP concentrations significantly increased in the capsaicin group. Additionally, the incidence of large-for-gestational-age (LGA) newborns was significantly lower in the capsaicin group than in the placebo group.
The study concludes that aapsaicin- containing chilli supplementation improved postprandial hyperglycemia and hyperinsulinemia as well as fasting lipid metabolic disorders in women with GDM, and it decreased the incidence of LGA newborns (14).
Did you know?
A patent US skin cream called Zostrix that uses capsaicin has been clinically proven to improve healing from postherpetic neuralgia and reduce pain in diabetic neuropathy.
Chilli usually grows as a small shrub with green glossy leaves which can be long, lanceolate, or oval in shape with smooth margins and can reach up to 7.5 cm (3 inches) in length. The leaves of some cultivars turn dark purple or black as the plant grows. It can grow to a height of 0.3–1.2 metres and a width of 15–30 cm.
The star or bell-shaped flowers have 4–5 petals and are white, greenish, or purple in colour. The fruits are true berries and come in many shapes, sizes and degrees of spiciness i.e. bell peppers are large, roundish, and furrowed, whereas cayenne peppers are long and thin.
Depending on the cultivar, the fruits may be green, red, yellow, orange, or black, and many change colour as they mature. Given that the myriad of forms cross-pollinate easily, varieties and cultivars are often difficult to quantify and are usually classified by characteristics of the fruits, such as size, shape, colour, flavour, and degree of heat.
- Hot chilli
- Sweet chilli
- Bird pepper
- Bell pepper
- Cherry pepper
- Chilli pepper
Capsicum annuum is the most economically important of the species in the Capsicum genus. Its common forms include bell, poblano, cayenne, pimento (including those used to make paprika), jalapeño, serrano, and various other chilli peppers.
Other species of capsicum used in herbal medicine include C. frutescens and C. minimum. This monograph refers to the use of these Capsicum species.
It is important to note that while chilli is generally considered safe for use in normal food quantities or when used in recommended doses, it may cause side effects in some people, such as skin irritation and stomach upset.
It is important to consult a qualified healthcare practitioner before using chilli in medicinal doses, especially if you are pregnant, breastfeeding, or taking prescription medications.
Chilli has the potential to decrease the absorption of aspirin, increase the absorption of ciprofloxacin and theophylline, and alter the absorption of cefalexin and digoxin.
Chilli may also affect the metabolism of pentobarbital and phenazone. It is important to seek advice from a medical herbalist or qualified healthcare practitioner before using chilli in medicinal doses (17).
Chilli is contraindicated for use in cases of severe hypertension. It is also not recommended for use in gastric ulcers and hyperacidity.
Tincture (1:5 in 25%): Take between 0.25- 1ml in a little water up to 3 times a day.
Infusion: To make an infusion place half to one teaspoon of dried material in one cup of boiling water infuse for up to 10 minutes. Strain and set aside. Mix one tablespoon of this infusion in a cup of hot water and drink up to 3 times a day.
Plant parts used
- Capsaicinoid alkaloids: Capsaicin
- Carotenoid pigments: Capsanthin
- Ascorbic acid
- Volatile oils (10, 11)
The plant genus capsicum are native to southern North America, the Caribbean, and northern South America. It grows in tropical regions in the Americas. Its native habitat is in forests and shrub land.
According to the IUCN Red List of Threatened Plants Status chilli, particularly C. annuum, is classified as ‘least concern’. It is widely distributed and abundant. It is also encouraged and protected by humans and even though it is affected by several threats in portions of its range the overall population is stable (3).
Habitat loss and over-harvesting from the wild are two of the biggest threats faced by medicinal plant species. There are an increasing number of well-known herbal medicines at risk of extinction. We must therefore ensure that we source our medicines with sustainability in mind.
The herb supplement industry is growing at a rapid rate and until recent years a vast majority of medicinal plant produce in global trade was of unknown origin. There are some very real and urgent issues surrounding sustainability in the herb industry. These include environmental factors that affect the medicinal viability of herbs, the safety of the habitats that they are taken from, as well as the welfare of workers in the trade.
The botanical supply chain efforts for improved visibility (transparency and traceability) into verifiably sustainable production sites around the world is now certificated through the emergence of credible international voluntary sustainability standards (VSS). Read our article on sustainable sourcing of herbs to learn more about what to look for and questions to ask suppliers about sustainability.
The levels of capsaicin or capsaicinoids determine how hot a chilli feels, with the amount of ‘heat’ expressed with a tool called the Scoville Scale. The amount of heat is expressed in Scoville Heat Units (SHU). Each unit represents the number of times the concentration of capsaicinoids needs to be diluted before it’s no longer detectable. For example, the jalapeno pepper is measured at 2,000-8,000 SHUs, which means it took 2,000-8,000 dilutions for the heat quality to be undetectable. The scale starts at 0 SHUs with the bell pepper, which has no capsaicin compounds, to 3.2 million SHUs with Pepper X (16).
Herbal Medicines are often extremely safe to take, however it is important to buy herbal medicines from a reputed supplier. Sometimes herbs bought from unreputable sources are contaminated, adulterated or substituted with incorrect plant matter.
Some important markers for quality to look for would be to look for certified organic labelling, ensuring that the correct scientific/botanical name is used and that suppliers can provide information about the source of ingredients used in the product.
A supplier should be able to tell you where the herbs have come from. There is more space for contamination and adulteration when the supply chain is unknown.
How to grow
Chilli is easy to grow. They prefer a warm, sheltered and sunny position so will grow best indoors or in a conservatory or glass house in temperate regions.
- Sow seeds at 18-21°C (65-70°F) in pots of good seed sowing compost in late winter to early spring using fertile peat-free organic compost under glass or on a sheltered sunny patio.
- Transplant the seedlings individually into 9-10cm (3-4in) pots when two true leaves have formed, and grow them on at around 16-18°C (60-65°F).
- Gradually harden off the plants for 10-14 days before planting outside.
- Pinch out the growing tip of shoots to encourage a bushier plant. Keep picking fruit to encourage further flowering
Herbal analgesic liniment
A liniment is a herbal preparation that is used topically to help alleviate pain in sore muscles and soft tissues. It’s usually made with either rubbing alcohol or witch hazel along with a small amount of infused oil.
There are several herbs that can be included in a pain-relieving liniment. In this recipe, pain relieving and anti-inflammatory herbs have been included.
- 250ml Witch Hazel water or rubbing alcohol
- 2 Tbsp dried meadowsweet
- 2 Tbsp dried willow bark
- 2 Tbsp dried yarrow
- 2 Tbsp dried calendula
- 2 Tbsp dried daisy flower
- ½ tsp dried chilli or 1-2ml of capsicum tincture
- 30ml St. John’s Wort Tincture or infused oil
- 25 drops peppermint essential oil
Place all the dried herbs in a large clip top kilner jar. Cover with witch hazel or alcohol so that there is no herbal matter appearing over the top. Steep for 4-6 weeks, shaking daily. Strain and compost the herbs. Add St. John’s Wort tincture, capsicum tincture and essential oil, then bottle and label. A liniment may be most useful stored in a spray bottle for easy and quick application.
A liniment should be applied to the affected area and used up to 4 times a day.
- Bone, K. and Mills, S. (2013). Principles and practice of Phytotherapy modern Herbal Medicine. 2nd ed. Edinburgh Churchill Livingstone, Elsevier.
- Menzies-Trull, C. (2013). Herbal medicine keys to physiomedicalism including pharmacopoeia. Newcastle: Faculty Of Physiomedical Herbal Medicine (Fphm).
- Contreras, A., Menjívar, J., Cerén-López, G., Azurdia, C. and Aguilar-Meléndez, A. (2017). IUCN Red List of Threatened Species: Capsicum annuum. [online] IUCN Red List of Threatened Species. Available at: https://www.iucnredlist.org/species/100895534/172969027 [Accessed 7 Jul. 2023].
- March, J. (no date) European Union herbal monograph on Capsicum annuum L. var. minimum (Miller) Heiser and small fruited varieties of Capsicum frutescens L., fructus Final Discussion in Working Party on European Union monographs and list (MLWP) November, Europa.eu. Available at: https://www.ema.europa.eu/en/documents/herbal-monograph/final-european-union-herbal-monograph-capsicum-annuum-l-var-minimum-miller-heiser-small-fruited_en.pdf (Accessed: July 11, 2023).
- Bernstein, J.E., Bickers, D.R., Dahl, M.V. and Roshal, J.Y. (1987). Treatment of chronic postherpetic neuralgia with topical capsaicin. A preliminary study. Journal of the American Academy of Dermatology, [online] 17(1), pp.93–96. doi:https://doi.org/10.1016/s0190-9622(87)70178-9.
- Srinivasan, K. (2015). Biological Activities of Red Pepper (Capsicum annuum) and Its Pungent Principle Capsaicin: A Review. Critical Reviews in Food Science and Nutrition, 56(9), pp.1488–1500. doi:https://doi.org/10.1080/10408398.2013.772090.
- Whiting, S., Derbyshire, E. and Tiwari, B.K. (2012). Capsaicinoids and capsinoids. A potential role for weight management? A systematic review of the evidence. Appetite, 59(2), pp.341–348. doi:https://doi.org/10.1016/j.appet.2012.05.015.
- Leung, F.W. (2014). Capsaicin as an anti-obesity drug. Progress in Drug Research. Fortschritte Der Arzneimittelforschung. Progres Des Recherches Pharmaceutiques, [online] 68, pp.171–179. doi:https://doi.org/10.1007/978-3-0348-0828-6_7.
- Wood. M. 2004. The Practice of Traditional Western Herbalism: Basic Organs and Systems. North Atlantic Books,U.S.
- Mills, S.Y. (1993). The Essential Book of Herbal Medicine. Editorial: Penguin.
- Hoffmann, D. (2003). Medical Herbalism – principles and practices. Inner Traditions Bear And Comp.
- Ternesten-Hasséus, E., Johansson, E.-L. and Millqvist, E. (2015). Cough reduction using capsaicin. 109(1), pp.27–37. doi:https://doi.org/10.1016/j.rmed.2014.11.001.
- McCarty, M.F., DiNicolantonio, J.J. and O’Keefe, J.H. (2015). Capsaicin may have important potential for promoting vascular and metabolic health: Table 1. Open Heart, [online] 2(1), p.e000262. doi:https://doi.org/10.1136/openhrt-2015-000262.
- Yuan, L.-J., Qin, Y., Wang, L., Zeng, Y., Chang, H., Wang, J., Wang, B., Wan, J., Chen, S.-H., Zhang, Q.-Y., Zhu, J.-D., Zhou, Y. and Mi, M.-T. (2016). Capsaicin-containing chili improved postprandial hyperglycemia, hyperinsulinemia, and fasting lipid disorders in women with gestational diabetes mellitus and lowered the incidence of large-for-gestational-age newborns. Clinical Nutrition, 35(2), pp.388–393. doi:https://doi.org/10.1016/j.clnu.2015.02.011.
- Bernstein, J., Korman, N.J., Bickers, D.R., Dahl, M.V. and Millikan, L.E. (1989). Topical capsaicin treatment of chronic postherpetic neuralgia. 21(2), pp.265–270. doi:https://doi.org/10.1016/s0190-9622(89)70171-7.
- Watson, C.P., Tyler, K.L., Bickers, D.R., Millikan, L.E., Smith, S. and Coleman, E. (1993). A randomized vehicle-controlled trial of topical capsaicin in the treatment of postherpetic neuralgia. Clinical therapeutics, [online] 15(3), pp.510–526. Available at: https://europepmc.org/article/med/8364943 [Accessed 12 Jul. 2023].
- Williamson, E.M., Driver, S. and Baxter, K. (2013). Stockley’s herbal medicines interactions : a guide to the interactions of herbal medicines. London: Pharmaceutical Press.