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We share traditional, scientific and practical insights written by experienced herbalists and health experts from the world of herbal medicine and natural health

  • Herb overview

    Safety

    Generally well tolerated. Not recommended during the first trimester of pregnancy

    Sustainability

    Status: Low risk

    Key constituents

    Flavonoids
    Phenolic acids
    Volatile oils

    Quality

    Native to North America
    Wild harvested and cultivated
    Adulteration risks with other skullcap species and germander

    Key actions

    Anxiolytic
    Relaxant
    Nervine
    Thymoleptic

    Key indications

    Anxiety
    PMS
    Insomnia
    Stress

    Key energetics

    Cool
    Dry
    Relaxing
    Bitter

    Preperation and dosage

    Aerial parts
    Dried herb: Up to 6 g per day
    Tincture (1:5): Up to 13 ml per day

  • How does it feel?

    The infused tincture has a pleasant fresh, slightly sweet smell with an initially sweet and grassy taste with mildly bitter after tones. The dried herb has a gentle aroma redolent of fresh field mushrooms.

    Skullcap (Scutellaria lateriflora)
    Skullcap (Scutellaria lateriflora)
    Skullcap (Scutellaria lateriflora)

  • Into the heart of skullcap

    Skullcap is a deeply restorative and calming plant, offering a profound sense of support to frayed, exhausted or anxious states. It can be thought of as stepping in when the nervous system has extended beyond its boundaries and limitations — for example, if someone has been living under prolonged stress or in a heightened state of alert for too long. Instead of numbing stressful feelings or emotions, it helps to nurture the nerves back into a state of balance (2). 

    Energetically, it is cooling, drying, relaxing and restorative. This can extend to its action on providing clarity for scattered thoughts, as it helps to reduce excess dampness which can be a factor in looping thoughts or mental overstimulation (2,3). In contrast to other hypnotics such as hops (Humulus lupulus), skullcap doesn’t dull or sedate the mind, it brings clarity and helps to centre awareness (2,3). 

    Ayurvedic use of skullcap includes its use in lowering excessive pitta and for helping reduce heat-driven emotions such as hatred, anger or irritation. It also works to anchor vata when it is tense or overstimulated (7).

    It soothes the heart and is said to possess sattvic qualities, bringing about a clarity of mind. It is often combined with gotu kola (Centella asiatica) for such situations (7).

  • What practitioners say

    Nervous systemNervous system

    Skullcap is a key nervous system tonic, helping to restore frayed nerves, reduce nervous excitability and relieve tension. It is most effective in chronic states, for example in prolonged states of stress or nervous system dysregulation rather than acute inflammatory conditions (2,11). It can be applied to help in sympathetic overdrive, and in cases where cortisol levels have been heightened for an extended period (1,3).

    For use in cases of debility or nervous exhaustion, it can be prescribed in combination with adaptogenic or nervine herbs including ashwagandha (Withania somniferum), St John’s wort (Hypericum perforatum) or schisandra (Schisandra chinensis). The thymoleptic action also indicates skullcap in the treatment of low mood or depression (3,4). 

    In TCM, skullcap regulates Heart qi, and in particular where constrained qi arises from deficiency rather than excess, supporting its use in more chronic conditions (11). 

    Its relaxant effect helps to calm spasm, pain and tension resulting from stress. This can be applied to  insomnia, palpitations, neuralgia, phobias, muscular twitching, tremors and epilepsy (4,5). In TCM, it can be seen to treat internal wind conditions arising from deficiency (xu feng), which result in symptoms including tremors, twitching or convulsions (11). 

    Its calming and antispasmodic action can be attributed to its flavonoid content, notably baicalin and baicalein, which have been shown to positively modulate GABA-A receptor activity, enhancing inhibitory transmission without the more depressant effect experienced with benzodiazepines (1,13). Symptoms of withdrawal can often be associated with reduced GABAergic tone, and excess glutamatergic activity and, therefore, it can be of good benefit to aid withdrawal from barbiturates, tranquillisers or alcohol (1,13). It can also help to reduce spasms, tremor or convulsions as a result of its antispasmodic activity (3,4). 

    Acutely, it can be taken at the onset of a panic or anxiety attack and some people find it useful to carry a small bottle of the tincture with them to dose with if they feel acute anxiety coming on (3). .

    Reproductive system

    As a nervine relaxant and antispasmodic, it can be used to reduce tension or pain specific to the reproductive system such as with dysmenorrhoea, especially when the pain is worsened by stress or anxiety or results from restlessness or poor sleep (1,4). It can form part of a menstrual cramp prescription with the inclusion of black haw (Viburnum prunifolium) or cramp bark (Viburnum opulus) (1). 

    It can be prescribed in a mix of other herbs including peony (Paeonia lactiflora) to help reduce symptoms of endometriosis, including the pain, tension or sleep disturbance often associated with the condition (1). 

    Skullcap is a key herbal anxiolytic to support PMS mood symptoms, including anxiety, irritability, anger, despair or panic (4,13). In reducing feelings of stress and nervous system overactivity, skullcap helps to bring the whole body, including the hormonal and reproductive systems into a state of balance, which, in turn helps to minimise the severity of emotional PMS and PMDD symptoms (4,6,13). 

    In a blend with hormonal supportive herbs, such as agnus castus (Vitex agnus castus) or black cohosh (Cimicifuga racemosa), skullcap can provide support for menopausal symptoms including low mood, depression and mood swings (4,6). Its cooling nature, also indicates it to reduce hot flushes, especially when combined with herbs like sage (Salvia officinalis), for its cooling and astringent actions (6,13). As a thymoleptic herb, it can be applied to help in cases of postpartum depression (6). 

    In TCM, skullcap is seen to ‘calm the shen’ (an shen) and balance Heart shen disturbance as well as Heart yin deficiency accompanied by agitation. These conditions can manifest as PMS with anxiety or agitation and menstrual or menopausal symptoms exacerbated by stress (11). 

    Cardiovascular system

    Skullcap can be applied to treat cardiac symptoms as an expression of nervous system dysregulation including palpitations, stress related hypertension, fast heart rate or a feeling of being constricted in the chest arising from emotional factors (1,3,11). 

    Digestive system

    It can be given for digestive problems associated with stress, such as irritable bowel syndrome (IBS). The calming effect extends to reducing gut spasm arising from stress or anxiety and gut-brain dysregulation (1,3,11). 

  • Skullcap research

    Skullcap tincture (Scutellaria lateriflora)
    Skullcap tincture (Scutellaria lateriflora)

    Efficacy and tolerability of a chemically characterised Scutellaria lateriflora L. extract-based food supplement for sleep management: A single-center, controlled, randomised, crossover, double-blind clinical trial

    A randomised, double-blind, placebo-controlled, was carried out to evaluate the efficacy and tolerability of a Scutellaria lateriflora extract on sleep and insomnia. The study involved 66 male and female participants aged 18–70 years with diagnosed primary insomnia, who were randomly allocated in a 1:1 ratio to receive either 400 mg/day of S. lateriflora extract or placebo for 56 days, followed by a 28-day washout period and crossover to the alternate intervention.

    The primary outcome measure was sleep quality assessed using the Pittsburgh Sleep Quality Index (PSQI), with secondary outcomes including sleep onset latency, sleep efficiency, total sleep time, and subjective sleep assessment using a Visual Analogue Scale (VAS). Supplementation with S. lateriflora resulted in a statistically significant improvement in sleep–wake balance, reflected by improved PSQI scores and favourable changes across all secondary sleep parameters compared with placebo, while no adverse effects were reported. These results suggest skullcap is an effective and safe remedy for improving quality (14).

    American skullcap (Scutellaria lateriflora): A randomised, double-blind placebo-controlled crossover study of its effects on mood in healthy volunteers

    A randomised, double-blind, placebo-controlled, crossover study investigated the effects of Scutellaria lateriflora on mood and anxiety in 43 healthy adult volunteers, exploring its traditional use for stress and anxiety. Participants were randomised to receive 350 mg of S. lateriflora three times daily or placebo, over a two week treatment period, in a crossover sequence. The cohort was deemed non-anxious at baseline, with 81% scoring ≤15 on the Beck Anxiety Inventory (BAI), indicating mild or no anxiety.

    The primary anxiety outcome (BAI) showed no significant difference between skullcap and placebo (p = 0.191), although a significant group effect (p=0.049) suggested a carryover effect of skullcap. Secondary outcomes included mood assessment using the Profile of Mood States (POMS), where S. lateriflora produced a highly significant reduction in Total Mood Disturbance from baseline (p<0.001), an effect not observed with placebo (p=0.072).

    No reduction in energy or cognitive function was reported. The authors concluded that carryover effects, low baseline anxiety, and baseline group differences (p=0.022) were likely responsible for the reduced ability to detect anxiolytic effects. This calls for further investigation of S. lateriflora in more anxious populations, particularly those with comorbid low mood or depression (15).

    Traditional uses, ten-years research progress on phytochemistry and pharmacology, and clinical studies of the genus Scutellaria

    A comprehensive systematic review evaluated the ethnopharmacology, phytochemistry, pharmacology, and clinical research of the genus Scutellaria (Lamiaceae), consisting of approximately 360–469 accepted species distributed across Europe, North America, East Asia, and South America, and has a long history of traditional use for respiratory, gastrointestinal, neurological, hepatic, and gallbladder disorders.

    The authors explored published books and peer-reviewed literature sourced from SciFinder, Scopus, PubMed, Web of Science, Baidu Scholar, CNKI, ethnobotanical databases, and monographs, focusing on ethnopharmacological uses, phytochemical and pharmacological research, and clinical studies. The review identified over 50 species used in traditional medicine, and reported over 208 chemical constituents — including flavonoids, neo-clerodane diterpenoids, sesterterpenoids, and other terpenoids — have been characterised from 16 species and one variety.

    Pharmacological studies demonstrated a broad range of activities, including anti-inflammatory, antioxidant, antiviral, antibacterial, anticancer, hepatoprotective, neuroprotective, and cardiovascular and cerebrovascular effects. Importantly, several species — most notably Scutellaria lateriflora, alongside S. baicalensis and S. barbata — and key constituents such as baicalein, baicalin, and wogonin. These reviews go some way to confirming the traditional uses of skullcap (16). 

  • Historical use of skullcap

    Skullcap was used by Native American tribes to relieve breast pain, promote menstruation and in child birth to help expel the placenta. It was used within ceremonies for the transition of girls into womanhood and has been used variously for treating stress, insomnia, premenstrual syndrome and diarrhoea (2,3).

    In the 18th century skullcap was being used in mainstream American medicine for the treatment of rabies, particularly for the hysteria associated with the disease. This use as a cure for rabies was subsequently discredited, but not before earning it common names such as ‘mad dog weed’. Undoubtedly it would have helped to calm any anxiety and reduce spasm in those with the disease (8,9).

    In the 19th century the Physiomedicalists were using skullcap as a nervine for conditions of excitability, phobias, anxiety and seizures (10).

    It was considered a specific remedy for the convulsive twitchings of St Vitus’ dance, now known to have been an umbrella term for various types of conditions with movement disorders (10).

  • Skullcap’s herbal actions

    Herbal actions describe therapeutic changes that occur in the body in response to taking a herb. These actions are used to express how a herb physiologically influences cells, tissues, organs or systems. Clinical observations are traditionally what have defined these actions: an increase in urine output, diuretic; improved wound healing, vulnerary; or a reduction in fever, antipyretic. These descriptors too have become a means to group herbs by their effects on the body — herbs with a nervine action have become the nervines, herbs with a bitter action are the bitters. Recognising herbs as members of these groups provides a preliminary familiarity with their mechanisms from which to then develop an understanding of their affinities and nuance and discern their clinical significance.

    Western actions

    Ayurvedic actions

    Chinese actions

  • Skullcap’s energetic qualities

    Herbal energetics are the descriptions Herbalists have given to plants, mushrooms, lichens, foods, and some minerals based on the direct experience of how they taste, feel, and work in the body. All traditional health systems use these principles to explain how the environment we live in and absorb, impacts our health. Find out more about traditional energetic actions in our article “An introduction to herbal energetics“.

  • What can I use skullcap for?

    Skullcap (Scutellaria lateriflora)
    Skullcap (Scutellaria lateriflora)

    Skullcap is a nervous system tonic with some describing it as a nervous system trophorestorative as it helps to support depleted, overstimulated or exhausted nervous systems (1,2,3). It is indicated in long term nervous system stress, overwork, burn out or emotional strain by helping to restore calm and resilience (1,2,3). 

    This herb also offers nervine and antispasmodic activity, so can be applied to relax tension in cases where it is being held in the muscles, such as tension headaches, tightened shoulders, neck or lower back, palpitations, menstrual cramps, tremors, muscle spasms and leg cramps or neuralgia (1,2,3). 

    It is effective in cases of insomnia, especially when the mind is still active and ruminative thoughts are a constant feature preventing restful sleep, a common occurrence in nervous depletion (4,5). It is indicated for people who often feel ‘tired and wired’ and find it difficult to switch off (4,5). 

    It has traditionally been used to support the nervous system with withdrawal from alcohol, sedatives or other stronger drugs as it helps to reduce tremors, agitation and nervous irritability (2,3). 

    The supportive and anxiolytic properties indicate skullcap in supporting premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD) (6).

  • Did you know?

    The name skullcap comes from ‘small dish’ or ‘small shield’ referring to the helmet like shape of the calyx of the flower that can be seen after flowering (16). 

  • Botanical description

    The genus Scutellaria in the Lamiaceae (mint) family has approximately 350 species, some of which are medicinally active. A perennial herb native to North America and Canada favouring woods, thickets and damp areas such as riverbanks and marshes (17). 

    It has slender, toothed leaves and pale blue, or occasionally white or pink flowers produced on one side of the stem.

    Not to be confused with baikal skullcap (Scutellaria baicalensis), which is also used in Western herbal medicine and one of the most widely prescribed herbs in traditional Chinese medicine (TCM). Baikal skullcap has denser racemes of larger purple/blue flowers (5).

    It is important to correctly identify the species. Some skullcaps are labelled as S. lateriflora in garden nurseries can in fact be S. altissima, which has similar flavonoid content, but has not been widely explored for its medicinal benefit. Scutellaria lateriflora can be adulterated, or substituted with other plants, so take care to ensure it is obtained from a reputable source (18). 

    The whole aerial parts are used, best harvested while in flower late in summer.    

  • Common names

    • Skullcap
    • Virginia skullcap
    • Mad-dog skullcap
    • Mad-dog weed
    • Quaker bonnet
    • Blue pimpernel
    • Hood-wort

  • Habitat

    Skullcap is native to North America and Canada, however species like S. altissima are indigenous to the UK. The plant prefers marshes, swamps and wet meadows and can often be found growing on the banks of rivers or streams and in woodlands (19,20).

  • How to grow skullcap

    Scutellaria lateriflora prefers moist, nutrient rich soil with partial shade to mimic its preference for river banks and woodland edges. To grow from seeds, cold stratify first, then plant seedlings out when they are at least three inches tall, and space them 30–40 cm apart. Water well so the soil is moist, but not waterlogged, to ensure soil doesn’t dry out once they are established. 

    Harvest at the beginning of the flowering stage which is usually mid to late summer depending on climate and growing conditions. Harvest on a dry day and the plant can be used fresh or dried for later use (3,18).

  • Herbal preparation of skullcap

    •  Tincture
    •  Fluid extract
    •  Tea

  • Plant parts used

    Aerial parts

  • Dosage

    • Tincture (dried) (ratio 1:5| %): 2–4.5 ml up to three times per day (1,3)
    • Tincture (fresh) (ratio 1:2 | 45%: 1–3 ml up to three times per day (2)
    • Fluid extract (1:1 | 45%): 0.5–2 ml up to three times per day (1)
    • Infusion/decoction: 1–6 g per day of the dried aerial parts (1,3)

  • Constituents

    • Flavonoids: Predominantly baicalein and its glycoside baicalin, wogonin, scutellarein, scutellarin, lateriflorein. In addition — apigenin, hispidulin and luteolin 
    • Phenolic acids: Hydroxycinnamic acids including caffeic acid and chlorogenic acid. 
    • Volatile oils: Limonene, humulene, terpinol, caryophyllene 
    • Tannins (1,12)

  • Skullcap recipe

    Calming tea blend

    The following recipe gives quantities to make up a large jar of calming tea blend to store in the cupboard, ready for use.

    Ingredients

    How to make skullcap tea

    1. Combine all ingredients and mix well.
    2. Store in a sealed jar, or other airtight container.
    3. For a cup of calming tea, take two heaped teaspoonfuls of blend to a cupful of boiling water.
    4. Cover, let infuse for 8–10 minutes and then strain.
    5. You can add a small amount of honey if desired, then sit, sip and enjoy!
    6. Drink up to three cups daily.
Skullcap: Insomnia treatment

Skullcap: Insomnia treatment

  • Safety

    Skullcap is generally considered a safe and well tolerated medicine when used in the correct dosages (1,2,3).

    Limited studies on its use in pregnancy have shown no developmental or other harmful effects. It has a long history of use in women during pregnancy and lactation, however consultation with a medical herbalist is recommended in these instances. For safety, it is recommended to avoid during the first trimester (1,2,3).

    Overdose can result in confusion, stupor, and sometimes involuntary muscle spasms and twitches; however, the authenticity of the herb ingested was not always verified in reported cases (1,2,3).

    Reports of liver toxicity were found to be due to adulteration with other species including germander — known to be hepatotoxic  (21).

  • Interactions

    Theoretically, skullcap could potentiate CNS depressants, but this has not been confirmed in clinical studies (22,23). It is recommended to monitor patients on antihypertensive medication to mitigate the risk of hypotension (3,23).

  • Contraindications

    None known (1,2,3,5).

  • Sustainability status of skullcap

    Skullcap is not considered to be threatened or at risk and is not listed on IUCN redlist, nor is its habitat under threat from climate change (19,24).

    Read our article on Herbal quality & safety: What to know before you buy and Sustainable sourcing of herbs to learn more about what to look for and questions to ask suppliers about sustainability.

    You can also find out more about our herb categorisation in our Herb species sustainability guide.

  • Quality control

    Skullcap has been the subject of considerable adulteration in the past. Adulteration or substitution has occurred using other species of skullcap, or other herbs from the mint family and notably with hepatotoxic plants such as those of the Teucrium species. The 22nd edition of the US Dispensary (1937) described Scutellaria lateriflora as one of the most substituted and adulterated herbs in the Materia Medica. This problem was more prevalent in times gone by, however, it remains paramount to source from reputable stockists (24,25). 

    The herb was traditionally wild harvested, and is now mostly cultivated for commercial sale (1).

  • References

    1. Bone K, Mills S. Principles and Practice of Phytotherapy: Modern Herbal Medicine. 2nd ed. Edinburgh Churchill Livingstone, Elsevier; 2013.
    2. Wood M. The Practice of Traditional Western Herbalism : Basic Doctrine, Energetics, and Classification. North Atlantic Books, Cop; 2004.
    3. Hoffmann D. Medical Herbalism : The Science and Practice of Herbal Medicine. Healing Arts Press; 2003.
    4. Mcintyre A. Complete Herbal Tutor : The Definitive Guide to the Principles and Practices of Herbal Medicine (Second Edition). Aeon Books Limited; 2019.
    5. Fisher C. Materia Medica of Western Herbs. Aeon Books; 2018.
    6. Romm AJ, Hardy ML, Mills S, Abascal K. Botanical Medicine for Women’s Health. Churchill Livingstone; 2010.
    7. Frawley D, Lad V. The Yoga of Herbs : An Ayurvedic Guide to Herbal Medicine. Motilal Banarsidass; 2016.
    8. Spalding L. A history of the introduction and use of Scutellaria lateriflora (scullcap,) as a remedy for preventing and curing hydrophobia: occasioned by the the bite of rabid animals ; with cases ; accompanied with a plate of the plant – Digital Collections – National Library of Medicine. Nih.gov. Published 1819. Accessed January 22, 2026. http://resource.nlm.nih.gov/8601056 
    9. Thatcher J. American Modern Practice. Boston; 1817.
    10. King J. King’s American Dispensatory.; 1898.
    11. Holmes P. The Energetics of Western Herbs. Snow lotus press; 2020.
    12. Pengelly A. The Constituents of Medicinal Plants. Cab International; 2021.
    13. Trickey R. Women, Hormones and the Menstrual Cycle : Herbal and Medical Solutions from Adolescence to Menopause. Allen & Unwin ; London; 1999.
    14. Di Minno A, Morone MV, Buccato DG, et al. Efficacy and Tolerability of a Chemically Characterized Scutellaria lateriflora L. Extract-Based Food Supplement for Sleep Management: A Single-Center, Controlled, Randomized, Crossover, Double-Blind Clinical Trial. Nutrients. 2025;17(9):1491-1491. https://doi.org/10.3390/nu17091491 
    15. Brock C, Whitehouse J, Tewfik I, Towell T. American Skullcap (Scutellaria lateriflora): A Randomised, Double-Blind Placebo-Controlled Crossover Study of its Effects on Mood in Healthy Volunteers. Phytotherapy Research. 2013;28(5):692-698. https://doi.org/10.1002/ptr.5044 
    16. Grieve M. A Modern Herbal | Scullcaps. botanical.com. Published 1931. Accessed September 30, 2022. https://botanical.com/botanical/mgmh/s/scullc34.html 
    17. The Wildlife Trust. Skullcap | The Wildlife Trusts. www.wildlifetrusts.org. Accessed December 26, 2023. https://www.wildlifetrusts.org/wildlife-explorer/wildflowers/skullcap 
    18. Upton R, Graff A, Jolliffe G, Länger R, Williamson E. American Herbal Pharmacopoeia. Informa; 2010. https://doi.org/10.1201/b10413 
    19. Engels G. ABC Herbalgram – Skullcap. Herbalgram.org. Published 2026. Accessed January 23, 2026. https://www.herbalgram.org/resources/herbalgram/issues/83/table-of-contents/herbalgram-83-herb-profile-skullcap/ 
    20. Royal Botanical Gardens Kew. Scutellaria lateriflora L. | Plants of the World Online | Kew Science. Plants of the World Online. Accessed December 5, 2023. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:458402-1 
    21. Lin LZ, Harnly JM, Upton R. Comparison of the phenolic component profiles of skullcap (Scutellaria lateriflora) and germander (Teucrium canadenseandT. chamaedrys), a potentially hepatotoxic adulterant. Phytochemical Analysis. 2009;20(4):298-306. https://doi.org/10.1002/pca.1127 
    22. TRC Healthcare. NatMed Pro – Skullcap. Therapeuticresearch.com. Published 2025. Accessed January 23, 2026. https://naturalmedicines.therapeuticresearch.com/Data/ProMonographs/Skullcap#drug-interactions 
    23. Williamson EM, Driver S, Baxter K. Stockley’s Herbal Medicines Interactions : A Guide to the Interactions of Herbal Medicines. Pharmaceutical Press; 2013.
    24. Maiz-Tome L. IUCN Red List of Threatened Species: Scutellaria lateriflora. IUCN Red List of Threatened Species. Published June 2, 2015. Accessed December 12, 2023. https://www.iucnredlist.org/species/64324897/67730992 
    25. Council AB. Nonprofit Consortium Publishes Review of Skullcap Adulteration. Prnewswire.com. Published February 21, 2012. Accessed January 23, 2026. https://www.prnewswire.com/news-releases/nonprofit-consortium-publishes-review-of-skullcap-adulteration-139912893.html 

Meet our herbal experts

Rebecca Collison-Walker
- Herbalist

Dedicated to the path of natural health and healing, Rebecca Collison-Walker has worked in complementary health for over 10 years.

Read Rebecca's articles

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Aromatic
An ‘aromatic’ remedy, high in volatile essential oils, was most often associated with calming and sometimes ‘warming’ the digestion. Most kitchen spices and herbs have this quality: they were used both as flavouring and to ease the digestion of sometimes challenging pre-industrial foods. Many aromatics are classed as ‘carminatives’ and are used to reduce colic, bloating and agitated digestion. They also often feature in respiratory remedies for colds, chest and other airway infections. They are also classic calming inhalants and massage oils, and are the basis of aromatherapy for their mental benefits.
Astringent
The astringent taste you get with many plants (the most familiar is black tea after being stewed too long, or some red wines) is produced by complex polyphenols such as tannins. Tannins are used in concentrated form (e.g. from oak bark) to make leather from animal skins. The process of ‘tanning’ involves the coagulation of relatively fluid proteins in living tissues into tight clotted fibres (similar to the process of boiling an egg). Tannins in effect turn exposed surfaces on the body into leather. In the case of the lining of mouth and upper digestive tract this is only temporary as new mucosa are replenished, but in the meantime can calm inflamed or irritated surfaces. In the case of open wounds tannins can be a life-saver – when strong (as in the bark of broadleaved trees) they can seal a damaged surface. One group of tannins, the reddish-brown ‘condensed tannins’ are procyanidins, which can reduce inflammation and oxidative damage.
Bitter
Bitters are a very complex group of phytochemicals that stimulate the bitter receptors in the mouth. They were some of the most valuable remedies in ancient medicine. They were experienced as stimulating appetite and switching on a wide range of key digestive functions, including increasing bile clearance from the liver (as bile is a key factor in bowel health this can be translated into improving bowel functions and the microbiome). Many of these reputations are being supported by new research on the role of bitter receptors in the mouth and elsewhere round the body. Bitters were also seen as ‘cooling’ reducing the intensity of some fevers and inflammatory diseases.
Bland
Blandness refers to a mild, plain, non-stimulating taste and an energetic action that neither irritates nor strongly activates physiological processes. In traditional Chinese medicine, bland substances gently drain dampness and promote urination, relieving excess fluid whilst also preserving qi and yin. Western traditional medicine similarly associates healing with bland substances that avoid extremes of heat or cold and promote restoration of balance. Blandness signifies regulation by supporting elimination and normal tissue function without forceful stimulation, helping to create a gentle and balanced state of homeostasis.
Cooling
Traditional ‘cold’ or cooling’ remedies often contain bitter phytonutrients such a iridoids (gentian), sesiquterpenes (chamomile), anthraquinones (rhubarb root), mucilages (marshmallow), some alkaloids and flavonoids. They tend to influence the digestive system, liver and kidneys. Cooling herbs do just that; they diffuse, drain and clear heat from areas of inflammation, redness and irritation. Sweet, bitter and astringent herbs tend to be cooling.
Hot

Traditional ‘hot’ or ‘heating’ remedies, often containing spice ingredients like capsaicin, the gingerols (ginger), piperine (black or long pepper), curcumin (turmeric) or the sulfurous isothiocyanates from mustard, horseradish or wasabi, generate warmth when taken.

In modern times this might translate as thermogenic and circulatory stimulant effects. There is evidence of improved tissue blood flow with such remedies: this would lead to a reduction in build-up of metabolites and tissue damage.

Heating remedies were used to counter the impact of cold, reducing any symptoms made worse in the cold.

Mucilaginous
Mucilages are complex carbohydrate based plant constituents with a slimy or ‘unctuous’ feel especially when chewed or macerated in water. Their effect is due simply to their physical coating exposed surfaces. From prehistory they were most often used as wound remedies for their soothing and healing effects on damaged tissues. Nowadays they are used more for these effects on the digestive lining, from the throat to the stomach, where they can relieve irritation and inflammation such as pharyngitis and gastritis. Some of the prominent mucilaginous remedies like slippery elm, aloe vera and the seaweeds can be used as physical buffers to reduce the harm and pain caused by reflux of excess stomach acid. Mucilages are also widely used to reduce dry coughing. Here the effect seems to be by reflex through embryonic nerve connections: reduced signals from the upper digestive wall appear to translate as reduced activity of airway muscles and increased activity of airway mucus cells. Some seed mucilages, such as in psyllium seed, flaxseed (linseed) or guar bean survive digestion to provide bulking laxative effects in the bowel. These can also reduce rate of absorption of sugar and cholesterol.
Neutral
Neutral herbs are characterised as by balanced temperature and energetics — neither warming nor cooling, nor strongly dispersing nor consolidating, and are, therefore, used across a wide spectrum of constitutional and pathological states. In Chinese medicine, this level, calm quality supports the centre, and gently strengthens digestion, regulates fluids, and resolves damp without provoking too much heat or cold. In Western medicine, neutral herbs are regarded as equal in relation to hot/cold or damp/dry and capable of maintaining a state of equilibrium. Neutral herbs can be seen as moderating reactivity, and supporting homeostasis rather than forcing change.
Pungent
The pungent flavour refers to the powerful taste of hot spices including mustard (Brassica spp.), ginger (Zingiber officinale), horseradish (Amoracia rusticana), chilli (Capsicum spp.), and garlic (Allium sativum). These herbs act to enliven and invigorate the senses, and they often also have heating qualities. Unlike other tastes, the effect is not linked to a specific receptor on the tongue and instead acts through direct irritation of tissues and nerve endings. Energetically, pungent herbs are known to disperse energy (qi) throughout the body. Pharmacologically, pungent herbs dry excess moisture and mucus, as well as stimulate digestion and metabolism.
Resinous
Resins are most familiar as tacky discharges from pine trees (and as the substance in amber, and rosin for violin bows). They were most valued however as the basis of ancient commodities like frankincense and myrrh (two of the three gifts of the Three Wise Men to the baby Jesus) and getting access to their source was one benefit to Solomon for marrying the Queen of Sheba (now Ethiopia). Resins were the original antiseptic remedies, ground and applied as powders or pastes to wounds or inflamed tissues, and were also used for mummification. With alcohol distillation it was found that they could be dissolved in 90% alcohol and in this form they remain a most powerful mouthwash and gargle, for infected sore throats and gum disease. They never attracted much early research interest because they permanently coat expensive glassware! For use in the mouth, gums and throat hey are best combined with concentrated licorice extracts to keep the resins in suspension and add extra soothing properties. It appears that they work both as local antiseptics and by stimulating white blood cell activity under the mucosal surface. They feel extremely effective!
Salty
The salty flavour is immediately distinctive. A grain dropped onto the tongue is instantly moistening and a sprinkle on food enkindles digestion. This easily recognisable flavour has its receptors right at the front of the tongue. The salty flavor creates moisture and heat, a sinking and heavy effect which is very grounding for the nervous system and encourages stability. People who are solid and reliable become known as ‘the salt of the earth'.
Sharp
The sharp taste of some fruits, and almost all unripe fruits, as well as vinegar and fermented foods, is produced by weak acids (the taste is generated by H+ ions from acids stimulating the sour taste buds). Sour taste buds are hard-wired to generate immediate reflex responses elsewhere in the body. Anyone who likes the refreshing taste of lemon or other citrus in the morning will know that one reflex effect is increased saliva production. Other effects are subjective rather than confirmed by research but there is a consistent view that they include increased digestive activity and contraction of the gallbladder.
Sour
The sour taste occurs because of the stimulation of hydrogen ions which trigger the sour taste receptors on the tongue. The more acidic a substance, the more hydrogen ions will be released. The sour taste comes from acidic substances including citrus, fermented foods, tannins, and vinegars. Sour foods and herbs absorb excess moisture, whilst also increasing the production of saliva. Energetically, sour substances tonify the lungs, playing a role in disease prevention. Excessive use, however, can result in malabsorption of nutrients. Examples of sour herbs include, rosehips (Rosa canina), raspberry (Rubus idaeus), rhubarb (Rheum palmatum), schisandra (Schisandra chinensis), hawthorn (Crataegus monogyna) and ginkgo (Ginkgo biloba).
Sweet
In the days when most people never tasted sugar, ‘sweetness’ was associated with the taste of basic foods: that of cooked vegetables, cereals and meat. In other words sweet was the quality of nourishment, and ‘tonic’ remedies. Describing a remedy as sweet generally led to that remedy being used in convalescence or recovery from illness. Interestingly, the plant constituents most often found in classic tonics like licorice, ginseng are plant steroids including saponins, which also have a sweet taste.
Umami
The umami taste was originally discovered in 1985 in Japan and is directly translated from the Japanese as a ‘pleasant savoury taste’. It is referred to as the ‘fifth taste’ and is a salty, rich, and meaty flavour. The umami flavour is produced by amino acids (glutamic acid and aspartic acid) found in many food and plant sources including tomatoes, mushrooms, seaweeds and soy-based foods. Umami foods can improve nutritional absorption and digestion as there are also umami receptors in the gut as well as the mouth. Examples of umami herbs include green tea (Camellia sinensis), reishi (Ganoderma lucidum), nettle (Urtica dioica), cordyceps (Ophiocordyceps sinensis), shitake (Lentinula edodes) and bladderwrack (Fucus vesiculosus).

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