Herbs & Botanicals · Traditional European urinary tea
Heather
Calluna vulgaris · also called Common heather, ling, Scotch heather, brezo (Spanish)
Heather is a low moorland shrub whose flowering tops are used in Europe as a traditional urinary tea and mild diuretic. Almost all the research is in test tubes and animals; we found no trial in people. It contains arbutin, the same marker compound as bearberry (uva ursi). A urinary infection needs a doctor, not a herbal tea, and heather should be avoided in pregnancy and breastfeeding.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Heather
Heather (Calluna vulgaris) is a low shrub of moors and heaths. Its flowering tops are used as a traditional European urinary tea and as a mild diuretic. The evidence is extremely thin: no clinical trial was found, and the research is test-tube work showing that extracts slow some urinary bacteria, plus reviews of its plant chemistry. It contains arbutin, which the body turns into hydroquinone, the reason related bearberry (uva ursi) is used and limited. The reference we read says avoid heather in pregnancy and breastfeeding and notes that safety has not been properly assessed. A urinary infection can reach the kidneys, so see a doctor rather than relying on tea. Ask a doctor or pharmacist about amounts.
What it is
Heather is a low evergreen shrub in the heath family (Ericaceae), the same family as bearberry, cranberry and blueberry. The medicinal part is the flowering tops, used as tea.
Names can be confusing: other heaths (Erica species) are also called heather, and heather honey is a different product. This page covers the herb Calluna vulgaris.
Traditional uses and what research exists
In European folk medicine heather tea is a urinary "antiseptic" and a diuretic. Reference texts also list diarrhoea and sleeplessness. No regulator recognition was found; we could not find an EU monograph for heather.
The research is almost entirely laboratory work. In test tubes, heather extracts slowed bacteria found in urinary infections, especially Proteus. Other lab work looked at mood-related enzymes, antioxidants and skin damage in mice. None of this shows an effect in people.
Heather and bearberry
Heather shares the marker compound arbutin with bearberry (uva ursi) and pipsissewa. Bearberry has trials and EU rules; heather has neither. Its trial result was mixed: fewer antibiotics but worse symptoms and more kidney infections than an antibiotic. Do not assume heather works or is safe because bearberry is studied.
At a glance
Traditional uses history, not proof
- European folk medicine: a tea of the flowering tops as a urinary "antiseptic" and diuretic
- Reference texts also list astringent use for diarrhoea and a remedy for sleeplessness
- Danish folk medicine for low mood and anxiety
Studied for research
- Urinary tract: test-tube activity against urinary bacteria, insufficient evidence (no human study)
- Mood and anxiety: lab findings only, insufficient evidence
- Antioxidant and anti-inflammatory activity: lab only, insufficient evidence
Main compounds
- Arbutin (the main hydroquinone-type compound)
- Flavonoids such as rutin and hyperoside
- Chlorogenic acid
- Tannin-type compounds (catechins)
Common forms
- Dried flowering herb as tea; capsules or powder; liquid or dry extracts (lab studies used extracts, not tea)
- Heather honey is a different product and is not covered here
Research links: Natural Medicines monograph: Heather (via vital.ly) · Lab study of heather against urinary bacteria (2014) · Review of Calluna vulgaris chemistry and activity (2022) · Research Library · Genes & Biomarkers Library
The plant and its history
- Accepted scientific name
- Calluna vulgaris (L.) Hull
- Naming authority
- (L.) Hull
- Synonyms
- GBIF lists many synonyms, for example Calluna alpestris, Calluna atlantica, Calluna erica; also Erica vulgaris L. in the consumer reference.
- Common names
- Heather (English); Common heather (English); Ling (English); Scotch heather (English); Brezo (Spanish); Bruyere commune (French)
- Botanical family
- Ericaceae (heath family), the same family as bearberry (uva ursi), cranberry and blueberry.
- Classification
- Plantae > Tracheophyta > Magnoliopsida > Ericales > Ericaceae > Calluna > Calluna vulgaris
- Native range
- Not verified from a primary source read. A review calls it widespread in Europe and spread to other continents.
- Habitat
- Not verified.
- What the plant looks like
- Roots: Not covered.; Stems: Low evergreen shrub (general knowledge, not verified in a source read).; Leaves: Not covered.; Flowers: Flowering tops are the traditional medicinal part.; Fruit: Not covered.
- Cultivation
- Not verified.
- Harvest and processing
- Not verified.
- Look-alikes and adulterants
- Name: Other heaths (Erica species); Note: Names like heather and heath cover Erica and Calluna; the consumer reference lists Erica vulgaris as a synonym. Not verified botanically here.; Name: Bearberry (Arctostaphylos uva-ursi); Note: Related urinary herb with more evidence and stricter rules; not the same plant.
- Sustainability and conservation
- Not verified. A review describes it as invasive in some regions and valued for nature conservation elsewhere.
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| European folk medicine | Flowering tops as a tea for the urinary tract (traditional "antiseptic") and as a diuretic; also astringent use for diarrhoea and for sleeplessness per a reference text. No regulator recognition found. | s-altmeyers-callunae |
| Danish folk medicine | Used for depression and anxiety; screened in the lab in 2013. | p23266274 |
Traditional use shows how a plant was used. It does not show that a supplement works or is safe today.
What is inside, and how it may work
What the plant contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Arbutin PubChem 440936 | hydroquinone glucoside (phenolic glycoside) | Herb (aerial parts) | The main hydroquinone derivative in heather extracts. In the body it is turned into hydroquinone, a urinary antiseptic. Content in products is not known. 9 6 11 | Laboratory research |
| Hydroquinone PubChem 785 | hydroquinone | Formed from arbutin | Released from arbutin in the body and urine; E. coli can free it from conjugates. 8 11 | Human data |
| Chlorogenic acid PubChem 1794427 | hydroxycinnamic acid | Herb | Dominant hydroxycinnamic acid in the extracts. 9 | Laboratory research |
| Rutin PubChem 5280805 | flavonoid | Herb | One of the dominant flavonoids. 9 | Laboratory research |
| Hyperoside PubChem 5281643 | flavonoid | Herb | One of the dominant flavonoids. 9 | Laboratory research |
| Quercetin glycosides PubChem 5280343 | flavonoid | Herb | Quercetin-3-glucoside was among the dominant flavonoids (CID is for quercetin itself). 9 | Laboratory research |
| Gallocatechin and epigallocatechin | tannin-type (catechin) compounds | Herb | Dominant tannin metabolites; no CID looked up. 9 | Laboratory research |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Bacterial growth (urinary strains) | Not identified | Heather extracts slowed E. coli, E. faecalis and P. vulgaris growth in a dish; water extract MIC 2.5 to 20 mg/ml. 10 | Laboratory research |
| MAO-A enzyme | MAO-A | Water extract blocked MAO-A in an enzyme test (IC50 8 ug/ml). 4 | Laboratory research |
| Mood-related behaviour, inflammation | Not stated | A 2020 paper reports anxiolytic, stress-protective, antidepressant and anti-inflammatory effects of the 70% alcohol-water extract; the abstract does not say whether cells or animals. 9 | Laboratory research |
Absorption, metabolism and elimination
- Absorption
- No data for heather. For arbutin from a pharmaceutical product, 4 volunteers excreted free hydroquinone in urine.
- Distribution
- Not found.
- Metabolism
- Arbutin is converted to hydroquinone conjugates and E. coli in urine can release free hydroquinone (from uva ursi/arbutin studies, not heather).
- Elimination
- Not found for heather.
- Bioavailability
- Not established for heather.
Isolated compounds versus whole extracts
Heather extracts hold arbutin plus many other polyphenols; no study compared the whole extract with arbutin alone.
Nutritional composition
A nutrient table is not meaningful for a medicinal tea herb.
7 not enough evidence
What is Heather good for?
The main traditional uses and how strong the evidence is for each. For all of them it is insufficient: no human trial was found.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Urinary tract (traditional "antiseptic" tea)
Not enough evidenceHeather tea has long been used in Europe for the bladder and urinary tract. The only research is in test tubes, where heather extracts slowed the growth of some bacteria found in urine infections. No study has tested heather in people with a urinary infection, so we cannot say it works.
3 studiesThe lab used plant extracts, not tea. Amounts in tea or products are …
Studies, doses and limits
What the trials found
None found. No clinical trial of heather for urinary infection or any urinary outcome turned up in the searches done for this page.
Results
Test-tube: water extract of heather stopped growth of E. coli, Enterococcus faecalis and Proteus vulgaris strains at 2.5 to 20 mg/ml; Proteus was most sensitive.
Effect sizes as reported
Lab MIC 2.5 to 20 mg/ml (water extract). No human effect size exists.
Why this rating
Evidence is limited to laboratory work on bacteria. There are no animal infection studies and no human data on heather found.
Form and dose studied
The lab used plant extracts, not tea. Amounts in tea or products are not known and this page gives no amounts.
Who was studied
None studied.
Limits
Lab-only; extracts and concentrations not comparable to a cup of tea; the effect on bacteria in a dish does not show treatment of an infection.
Why researchers looked
Heather is in the same plant family as bearberry (uva ursi) and contains the same marker compound, arbutin. Bearberry is the better-known urinary herb, so researchers asked whether heather also acts on urinary germs.
Traditional use
Traditional urinary tea and "antiseptic" in European folk medicine; one consumer drug reference lists kidney and urinary tract conditions among the many traditional uses.
Proposed mechanism Preliminary mechanism
In the lab, heather extracts slowed several urinary bacteria; arbutin and other phenolic compounds are the likely reason. Arbutin is turned into hydroquinone, which is what gives bearberry its antiseptic action in urine. Whether enough of heather's arbutin ever reaches urine in people is not known.
A proposed mechanism does not show that the effect happens in people.
A urinary infection can spread to the kidneys. Heather should not replace medical care for one. See the Safety tab.
Diuretic ("water pill") use
Not enough evidenceHeather is called a diuretic in traditional use, meaning a plant that makes you pass more urine. We found no human or animal study that actually measured this, so the claim rests on tradition alone.
2 studiesNot applicable.
Studies, doses and limits
What the trials found
None found.
Results
No study measured urine output with heather.
Effect sizes as reported
None.
Why this rating
No research measured it.
Form and dose studied
Not applicable.
Who was studied
None studied.
Limits
Traditional claim only.
Why researchers looked
Folk medicine pairs diuretic herbs with urinary complaints, and heather is listed in that group.
Traditional use
Listed as a diuretic in traditional texts and in a consumer drug reference summary.
Proposed mechanism Unknown
No mechanism has been shown for heather.
A proposed mechanism does not show that the effect happens in people.
If a diuretic effect did exist, it could matter for people on water pills, lithium or kidney medicines. This is theory; see the Safety tab.
Anxiety, stress and mood
Not enough evidenceA 2020 paper reported that a heather extract had calming and antidepressant-like effects in laboratory testing, and another lab test found heather blocked an enzyme (MAO-A) that antidepressant drugs also target. No one has tested heather for anxiety, stress or low mood in people.
2 studiesLab extracts only.
Studies, doses and limits
What the trials found
None found.
Results
Heather water extract inhibited MAO-A in an enzyme test (IC50 8 ug/ml) but did not look promising as a serotonin reuptake inhibitor. A 2020 paper reports anxiolytic, stress-protective and antidepressant effects of the 70% alcohol-water extract; its abstract does not say whether in cells or animals.
Effect sizes as reported
MAO-A IC50 8 ug/ml (enzyme test). Others: no numbers in the abstract.
Why this rating
Lab or animal findings only, with unclear models for the mood claims, and nothing in people.
Form and dose studied
Lab extracts only.
Who was studied
None studied.
Limits
Enzyme and preclinical work; an effect in a dish often does not carry over to people. Unknown if these extracts match a tea.
Why researchers looked
Heather appears in Danish folk medicine for depression and anxiety, and was screened in the lab for that reason.
Traditional use
Folk use for low mood and anxiety in Denmark; a reference text also lists sleeplessness.
Proposed mechanism Preliminary mechanism
Heather water extract blocked the MAO-A enzyme in a test tube. MAO-A breaks down mood-related brain chemicals, and some antidepressant drugs block it. It is a lab clue, not proof of any effect in a person.
A proposed mechanism does not show that the effect happens in people.
Any real MAO-A effect would be a reason to avoid combining heather with antidepressants or other mood medicines; no human interaction data exist. Talk to a pharmacist.
Antioxidant and anti-inflammatory activity (lab)
Not enough evidenceHeather is rich in plant polyphenols, and lab tests show antioxidant and anti-inflammatory activity. This is common to many plants and has not been shown to help any health condition in people.
3 studiesLab extracts only.
Studies, doses and limits
What the trials found
None found.
Results
All eight European plant extracts in one screen, including heather, showed antioxidant activity. Reviews describe anti-inflammatory activity in lab models.
Effect sizes as reported
No usable numbers in the abstracts for heather.
Why this rating
Lab findings only; antioxidant tests in a dish rarely predict benefit in people.
Form and dose studied
Lab extracts only.
Who was studied
None studied.
Limits
Not tested in people; heather results not separated out in the multi-plant study.
Why researchers looked
Heather herb and heather honey contain many phenolic compounds (chlorogenic acid, flavonoids, tannin-type compounds).
Traditional use
Traditional use as a general tea for rheumatic and other complaints is mentioned in references; not tested.
Proposed mechanism Preliminary mechanism
Polyphenols can mop up reactive oxygen molecules and affect inflammation signals in cells. These are lab effects.
A proposed mechanism does not show that the effect happens in people.
In one multi-plant cell test, some extracts were toxic to normal cells, so lab activity is not the same as safety.
Skin protection from UV light (mouse study)
Not enough evidenceIn one study, hairless mice given a heather gel before UV light had less sun-related skin DNA damage and fewer sunburn cells. That is a mouse study. It does not show that heather protects human skin and it is not a sunscreen.
1 studiesGel with heather extract, in mice.
Studies, doses and limits
What the trials found
None found.
Results
Heather gel reduced UVB-induced DNA damage (CPDs) and sunburn cells (both P < 0.001) compared with UVB alone.
Effect sizes as reported
P < 0.001 on both outcomes; no percentages in the abstract.
Why this rating
A single animal study with no human data.
Form and dose studied
Gel with heather extract, in mice.
Who was studied
Hairless mice only.
Limits
One mouse study; not people; not a sunscreen replacement.
Why researchers looked
Plant polyphenols are tested as possible skin protectors.
Traditional use
Not a traditional use.
Proposed mechanism Preliminary mechanism
The authors point to antioxidant, anti-inflammatory and DNA-protective effects of the polyphenols.
A proposed mechanism does not show that the effect happens in people.
Do not use heather instead of sunscreen.
Germ-slowing effect on non-urinary bacteria (lab)
Not enough evidenceHeather herb extracts slowed the growth of several bacteria, including germs that cause mastitis in cows, in test tubes. That is a lab result about animal-disease bacteria and says nothing about treating infection in people.
1 studiesLab solvent extracts.
Studies, doses and limits
What the trials found
None.
Results
Heather herb extracts acted on all tested bacteria, more on Gram-positive types; weaker alcohol solvents worked best.
Effect sizes as reported
r = -0.507 between solvent strength and effect (p < 0.05).
Why this rating
Lab only, and on animal-disease bacteria.
Form and dose studied
Lab solvent extracts.
Who was studied
None.
Limits
Not a treatment study.
Why researchers looked
Searching for plant alternatives to antibiotics in dairy animals.
Traditional use
Not applicable.
Proposed mechanism Preliminary mechanism
Polyphenols and tannin-like compounds can damage bacterial membranes in a dish.
A proposed mechanism does not show that the effect happens in people.
None specific.
Diarrhoea and sleeplessness (traditional)
Not enough evidenceA reference text lists heather as an astringent for diarrhoea and a remedy for sleeplessness. We found no trial of either use.
2 studiesNot applicable.
Studies, doses and limits
What the trials found
None found.
Results
No study.
Effect sizes as reported
None.
Why this rating
Traditional listing only.
Form and dose studied
Not applicable.
Who was studied
None.
Limits
One secondary reference; no trials.
Why researchers looked
Tannins are astringent, a classic reason for using a plant against diarrhoea.
Traditional use
Listed in a naturopathy reference text; not checked against an original source.
Proposed mechanism Unknown
Not studied.
A proposed mechanism does not show that the effect happens in people.
Persistent or bloody diarrhoea, or severe diarrhoea in children, needs medical care.
Connections to the rest of health
How Heather connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
A. Wellness goals
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Urinary Support | Traditional use | Not enough evidence | Urinary tract (traditional "antiseptic" tea): Heather tea has long been used in Europe for the bladder and urinary tract. The only research is in test tubes, where heather extracts slowed the growth of some bacteria found in urine infections. No study has tested heather in people with a urinary infection, so we cannot say it works. Diuretic ("water pill") use: Heather is called a diuretic in traditional use, meaning a plant that makes you pass more urine. We found no human or animal study that actually measured this, so the claim rests on tradition alone. | 10 2 15 |
| Stress Reduction | Potential benefit | Not enough evidence | Anxiety, stress and mood: A 2020 paper reported that a heather extract had calming and antidepressant-like effects in laboratory testing, and another lab test found heather blocked an enzyme (MAO-A) that antidepressant drugs also target. No one has tested heather for anxiety, stress or low mood in people. | 4 9 |
| Anxiety Support | Potential benefit | Not enough evidence | Anxiety, stress and mood: A 2020 paper reported that a heather extract had calming and antidepressant-like effects in laboratory testing, and another lab test found heather blocked an enzyme (MAO-A) that antidepressant drugs also target. No one has tested heather for anxiety, stress or low mood in people. | 4 9 |
| Mood Balance | Potential benefit | Not enough evidence | Anxiety, stress and mood: A 2020 paper reported that a heather extract had calming and antidepressant-like effects in laboratory testing, and another lab test found heather blocked an enzyme (MAO-A) that antidepressant drugs also target. No one has tested heather for anxiety, stress or low mood in people. | 4 9 |
| Inflammation Balance | Potential benefit | Not enough evidence | Antioxidant and anti-inflammatory activity (lab): Heather is rich in plant polyphenols, and lab tests show antioxidant and anti-inflammatory activity. This is common to many plants and has not been shown to help any health condition in people. | 9 2 5 |
| Cellular Protection | Potential benefit | Not enough evidence | Antioxidant and anti-inflammatory activity (lab): Heather is rich in plant polyphenols, and lab tests show antioxidant and anti-inflammatory activity. This is common to many plants and has not been shown to help any health condition in people. | 9 2 5 |
| Healthy Skin | Potential benefit | Not enough evidence | Skin protection from UV light (mouse study): In one study, hairless mice given a heather gel before UV light had less sun-related skin DNA damage and fewer sunburn cells. That is a mouse study. It does not show that heather protects human skin and it is not a sunscreen. | 7 |
| Immune Support | Potential benefit | Not enough evidence | Germ-slowing effect on non-urinary bacteria (lab): Heather herb extracts slowed the growth of several bacteria, including germs that cause mastitis in cows, in test tubes. That is a lab result about animal-disease bacteria and says nothing about treating infection in people. | 16 |
| Digestive Support | Traditional use | Not enough evidence | Diarrhoea and sleeplessness (traditional): A reference text lists heather as an astringent for diarrhoea and a remedy for sleeplessness. We found no trial of either use. | 12 15 |
| Better Sleep | Traditional use | Not enough evidence | Diarrhoea and sleeplessness (traditional): A reference text lists heather as an astringent for diarrhoea and a remedy for sleeplessness. We found no trial of either use. | 12 15 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Urinary System | Biological association | Not enough evidence | Studied for: Urinary tract (traditional "antiseptic" tea) | 10 2 15 |
| Kidney Urinary | Biological association | Not enough evidence | Studied for: Urinary tract (traditional "antiseptic" tea) Studied for: Diuretic ("water pill") use | 10 2 15 |
| Stress Mood | Biological association | Not enough evidence | Studied for: Anxiety, stress and mood | 4 9 |
| Pain Inflammation | Biological association | Not enough evidence | Studied for: Antioxidant and anti-inflammatory activity (lab) | 9 2 5 |
| Skin | Biological association | Not enough evidence | Studied for: Skin protection from UV light (mouse study) | 7 |
| Immune Support | Biological association | Not enough evidence | Studied for: Germ-slowing effect on non-urinary bacteria (lab) | 16 |
| Gut Health | Biological association | Not enough evidence | Studied for: Diarrhoea and sleeplessness (traditional) | 12 15 |
| Sleep Recovery | Biological association | Not enough evidence | Studied for: Diarrhoea and sleeplessness (traditional) | 12 15 |
C. Body parts and organs
D. Symptoms
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Urinary tract infection | Potential benefit | Not enough evidence | Test-tube activity only; no human study. Preparation or compound: Heather herb extracts |
10 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Pregnancy and breastfeeding | Contraindication | Authoritative guidance | Avoid; not enough reliable information. Preparation or compound: Heather herb |
15 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Growth of urinary bacteria in a lab dish | Biological association | Not enough evidence | Measured in trials: lowered. A lab change is not the same as a health benefit. | 10 |
| MAO-A enzyme activity (lab) | Biological association | Not enough evidence | Measured in trials: lowered. A lab change is not the same as a health benefit. | 4 |
| UVB skin DNA damage (CPDs), mice | Biological association | Not enough evidence | Measured in trials: lowered. A lab change is not the same as a health benefit. | 7 |
J. Genes, receptors and enzymes
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| MAO-A | Preliminary mechanism | In vitro | Heather water extract inhibited MAO-A in an enzyme assay. | 4 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Arbutin | Biological association | In vitro | The main hydroquinone derivative in heather extracts. In the body it is turned into hydroquinone, a urinary antiseptic. Content in products is not known. Preparation or compound: Herb (aerial parts) |
9 6 11 |
| Hydroquinone | Biological association | Human | Released from arbutin in the body and urine; E. coli can free it from conjugates. Preparation or compound: Formed from arbutin |
8 11 |
| Chlorogenic acid | Biological association | In vitro | Dominant hydroxycinnamic acid in the extracts. Preparation or compound: Herb |
9 |
| Rutin | Biological association | In vitro | One of the dominant flavonoids. Preparation or compound: Herb |
9 |
| Hyperoside | Biological association | In vitro | One of the dominant flavonoids. Preparation or compound: Herb |
9 |
| Quercetin glycosides | Biological association | In vitro | Quercetin-3-glucoside was among the dominant flavonoids (CID is for quercetin itself). Preparation or compound: Herb |
9 |
| Gallocatechin and epigallocatechin | Biological association | In vitro | Dominant tannin metabolites; no CID looked up. Preparation or compound: Herb |
9 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 25, 2026).
Evidence at a glance: what changed in 3 lab markers
Tap a number to show only those markers. Counts are markers, not people.
The evidence
The research centre for Heather. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We read the nutrient summary we hold, searched PubMed, checked GBIF and PubChem, and tried EMA, NCCIH and NLM pages (none found for heather). Only abstracts were read for papers. The Natural Medicines reference was read as a web page. EU rules for bearberry are second-hand. Certainty ratings are our own reading. No study is cited that we could not verify.
Study library: every study we checked 16
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Aydemir 2015 Hypersensitivity pneumonitis caused by the broom grass (Calluna vulgaris) Respiratory Medicine Case Reports · PMID 26236625 · DOI |
Case report |
1 35-year-old woman working in broom manufacturing |
Fever, cough and breathlessness for 3 months; CT showed diffuse ground-glass changes; she was treated with intravenous prednisolone and almost fully recovered. Single case Methods, limits and fundingOutcomes: Lung symptoms and CT findings Limitations: One case; cause assumed from her job. It concerns workplace dust, not tea or supplements. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Cucu 2022 Calluna vulgaris as a Valuable Source of Bioactive Compounds: Exploring Its Phytochemical Profile, Biological Activities and Apitherapeutic Potential Plants (Basel) · PMID 35956470 · DOI |
Narrative review review |
Review of heather plant and heather honey literature | Describes antioxidant, anti-inflammatory, antimicrobial and chemoprotective properties, mainly linked to phenolic compounds. It frames these as grounds for future study, not proven benefits. No pooled numbers Methods, limits and fundingOutcomes: Nutritional profile, chemistry and biological activities Limitations: Narrative review, not a systematic one. The abstract describes no human trials. Much of the paper covers honey, a different product. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Gágyor 2021 Herbal treatment with uva ursi extract versus fosfomycin in women with uncomplicated urinary tract infection in primary care: a randomized controlled trial Clinical Microbiology and Infection · PMID 34111592 · DOI |
Controlled trial |
398 Women with suspected uncomplicated urinary tract infection in German family practices |
Uva ursi cut antibiotic courses by 63.6% but gave a higher symptom burden (failed non-inferiority) and 8 kidney infections (pyelonephritis) vs 2 on fosfomycin (p = 0.067). Antibiotic courses 63.6% lower; symptom ratio 136.5% (95% CI 122.7 to 151.9) Methods, limits and fundingOutcomes: Antibiotic courses; symptom burden; complications Limitations: This tested uva ursi, not heather. It is included only because it shows why a bladder infection needs proper care. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Jäger 2013 Screening of plants used in Danish folk medicine to treat depression and anxiety for affinity to the serotonin transporter and inhibition of MAO-A Journal of Ethnopharmacology · PMID 23266274 · DOI |
Laboratory research lab |
Water and ethanol extracts of 17 plants in enzyme and receptor assays | The heather water extract blocked the MAO-A enzyme in the test (IC50 8 ug/ml), among the stronger results of the 17 plants. None of the plants looked promising as serotonin reuptake inhibitors. IC50 8 ug/ml (MAO-A) Methods, limits and fundingOutcomes: Serotonin transporter binding; MAO-A enzyme inhibition Limitations: Enzyme test only. MAO-A inhibition in a dish does not show any effect on mood in people, and it is also the reason for caution with some medicines. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Martins de Deus 2023 Chemical Characterization, Bioactivity and Toxicity of European Flora Plant Extracts in Search for Potential Natural Origin Preservatives Plants (Basel) · PMID 37570937 · DOI |
Laboratory research lab |
Extracts of eight European plants, including Calluna vulgaris, tested in cell lines and brine shrimp | All extracts showed antioxidant potential. Brine-shrimp tests suggested low toxicity for most extracts (LC50 above 400 mg/L). Some extracts were toxic to normal cells; heather, grape and raspberry extracts were active against tumour cells at lower concentrations than those toxic to normal cells. LC50 > 400 mg/L for most extracts (not given per plant in the abstract) Methods, limits and fundingOutcomes: Phenolics, antioxidant and antimicrobial tests, cell toxicity, brine-shrimp toxicity Limitations: Heather results are not separated out in the abstract. Cell and shrimp tests, not people. Aimed at food preservatives. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Nahar 2022 Arbutin: Occurrence in Plants, and Its Potential as an Anticancer Agent Molecules · PMID 36557918 · DOI |
Narrative review review |
Review of the compound arbutin across plants | Arbutin is found in about 50 plant families, including the Ericaceae (heather family). It is widely used for skin whitening. The authors report low acute or chronic toxicity and "potential" anticancer effects from lab work. No pooled numbers Methods, limits and fundingOutcomes: Where arbutin occurs; anticancer potential; toxicity Limitations: About the single compound arbutin, not heather. Lab-based anticancer claims; not a human cancer study. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Olteanu 2012 Photochemoprotective effect of Calluna vulgaris extract on skin exposed to multiple doses of ultraviolet B in SKH-1 hairless mice Journal of Environmental Pathology, Toxicology and Oncology · PMID 23339698 · DOI |
Animal research animal |
50 50 female hairless mice |
Heather gel lowered UVB-related DNA damage (CPDs) and sunburn cells (both P < 0.001) compared with UVB alone. P < 0.001 for CPDs and sunburn cells Methods, limits and fundingOutcomes: Skin inflammation markers (TNF-alpha, IL-6), DNA damage (CPDs), sunburn cells, skin thickness Limitations: Mice, not people, and applied to the skin. PubMed tags it a randomized controlled trial, but the animals were the subjects. Funding and conflicts: Not stated in the abstract (research support). Read: abstract | |
| Siegers 2003 Bacterial deconjugation of arbutin by Escherichia coli Phytomedicine · PMID 12807345 · DOI |
Human pk |
4 4 volunteers |
E. coli in the urine released 2.3 times more free hydroquinone from arbutin than an enzyme control did, which is how arbutin works as a urinary antiseptic. 2.3-fold higher free hydroquinone Methods, limits and fundingOutcomes: Free hydroquinone in urine Limitations: Four volunteers; a pharmaceutical arbutin product, not heather. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Starchenko 2020 Phytochemical Profile and Pharmacological Activities of Water and Hydroethanolic Dry Extracts of Calluna vulgaris (L.) Hull. Herb Plants (Basel) · PMID 32549372 · DOI |
Laboratory research lab |
Laboratory and preclinical models; the abstract does not say which models or how many animals | 19 phenolic substances were identified. Arbutin dominated the hydroquinone derivatives, chlorogenic acid the hydroxycinnamic acids; rutin, hyperoside and quercetin-3-glucoside the flavonoids; gallocatechin and epigallocatechin the tannin-type compounds. The authors report the 70% alcohol-water extract had the strongest effects in all their tests. No numbers in the abstract Methods, limits and fundingOutcomes: Phenolic profile by HPLC; anti-inflammatory, antimicrobial, anxiolytic, stress-protective, antidepressant effects Limitations: Abstract does not say whether the mood-related tests were in cells or animals, and gives no numbers. Not a human study. Authors are from herbal-pharmacy departments aiming at new drug or supplement development. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Vučić 2014 In vitro activity of heather [Calluna vulgaris (L.) Hull] extracts on selected urinary tract pathogens Bosnian Journal of Basic Medical Sciences · PMID 25428676 · DOI |
Laboratory research lab |
Bacterial strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris grown in the lab | All tested extracts slowed bacterial growth, most clearly the water extract. Proteus vulgaris was the most sensitive. Water extract MIC 2.5 to 20 mg/ml. Phenols 67.55 to 142.46 mg GAE/g; flavonoids 42.11 to 63.68 mg RUE/g. Aqueous extract MIC 2.5 to 20 mg/ml Methods, limits and fundingOutcomes: Minimum inhibitory and bactericidal concentrations; total phenols and flavonoids Limitations: Test-tube only; no animals or people. Concentrations that work in a dish say nothing about what reaches the bladder. Only the abstract (plus the summary file) was read here. Funding and conflicts: Not stated in the abstract (Research Support, Non-U.S. Gov't). Read: abstract | |
| de Arriba 2013 Risk assessment of free hydroquinone derived from Arctostaphylos Uva-ursi folium herbal preparations International Journal of Toxicology · PMID 24296864 · DOI |
Narrative review review |
Safety review of arbutin and hydroquinone from bearberry (uva ursi) leaf | Arbutin is absorbed, converted by the liver, and releases free hydroquinone in urine. The authors found no direct human evidence that free hydroquinone causes convulsions, liver or kidney toxicity or tumours, and judged recommended uva-ursi use safe. Authors are linked to a manufacturer of such products (affiliation not shown in the abstract), so treat the reassurance with care. Estimated maximal free HQ exposure 11 ug/kg/day vs a permitted level of 100 ug/kg/day (authors' estimate, for uva ursi) Methods, limits and fundingOutcomes: Free hydroquinone exposure and toxicity Limitations: About bearberry, not heather. Reassurance rests on the authors' own calculations. Industry link not confirmed from the abstract. Funding and conflicts: Not stated in the abstract; possible industry link (not verified). Read: abstract | |
| s-altmeyers-callunae Callunae herba (Altmeyers Encyclopedia of Naturopathy) · Source |
Reference book n/a |
Methods, limits and fundingRead: summary-only | ||
| s-ema-uva-ursi EU herbal monograph and assessment reports, Arctostaphylos uva-ursi folium (EMA/HMPC) · Source |
Regulator n/a |
Methods, limits and fundingRead: summary-only | ||
| s-gbif-calluna GBIF Backbone: Calluna vulgaris (L.) Hull · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-natmed-heather Heather (Natural Medicines monograph, shown via vital.ly) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| Šukele 2022 Antibacterial effects of oak bark (Quercus robur) and heather herb (Calluna vulgaris L.) extracts against the causative agents of bovine mastitis Veterinary World · PMID 36341072 · DOI |
Laboratory research lab |
Bacteria from cows with mastitis (E. coli, Streptococcus, Staphylococcus aureus and others), grown in the lab | Heather herb extracts acted against all the bacteria tested, better against Gram-positive ones. The weakest solvent (30% ethanol) gave the largest inhibition zones. No link between phenolic content and antibacterial effect (p not significant). Solvent strength vs effect: r = -0.507, p < 0.05 Methods, limits and fundingOutcomes: Disk-diffusion inhibition zones, MIC and MBC Limitations: Test-tube only, animal-disease bacteria, not urinary bacteria. Not a treatment study. Funding and conflicts: Not stated in the abstract. Read: abstract |
What we do not know yet
- What the evidence supports: almost nothing in people. It is lab work.
- What is uncertain: whether heather tea helps the urinary tract at all, whether it is a diuretic, and how much arbutin it delivers.
- What is missing: any clinical trial, safety study or interaction study.
How new research is added
New studies are found by a saved PubMed search and queued for a person to read before any rating or safety wording changes.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Other 3
Growth of urinary bacteria in a lab dish
Lowered in trials
How much of a plant extract is needed to stop bacteria growing in a test tube (minimum inhibitory concentration).
Not enough evidenceResults and what it means
Why it was measured
A first screen for plants used against urinary infection.
Statistical vs. clinical meaning
Shows the extract can act on bacteria in a dish. It does not show it works in a bladder or in people.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 10 | Water extract MIC 2.5 to 20 mg/ml; Proteus vulgaris most sensitive | Lab strains of E. coli, E. faecalis, P. vulgaris | Heather herb extracts |
MAO-A enzyme activity (lab)
Lowered in trials
A brain-chemistry enzyme that some antidepressants block.
Not enough evidenceResults and what it means
Why it was measured
A first screen for plants used in folk medicine for low mood.
Statistical vs. clinical meaning
A lab signal only; no human measurement.
Safety implication
A possible reason to be careful with antidepressants (theory).
| Study | Result | People | Product |
|---|---|---|---|
| 4 | Heather water extract IC50 8 ug/ml | Enzyme assay | Water extract of heather aerial parts |
UVB skin DNA damage (CPDs), mice
Lowered in trials
Cyclobutane pyrimidine dimers: a marker of UV damage to skin DNA.
Not enough evidenceSafety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 5
- Evidence is extremely thin. We found no clinical trial of heather. Safety knowledge rests on one consumer drug reference that calls it "possibly safe" with no reported side effects while stating that a high-quality safety assessment is lacking. "No reported side effects" here means little has been looked for. Authoritative guidance 15
- A urinary infection needs medical care. Heather tea has not been shown to treat or prevent urinary infection. Untreated bladder infections can reach the kidneys. See a doctor promptly for burning or frequent urination that does not clear quickly, and urgently for fever, shivering, back or flank pain, vomiting, or blood in the urine. In a trial of the related herb uva ursi against an antibiotic, 8 women developed a kidney infection vs 2 on the antibiotic (not statistically significant), and symptoms were worse. That is a different plant, but it shows the risk of herbal-only treatment. Controlled trial 3
- Arbutin and hydroquinone: borrowed caution from uva ursi. Heather herb contains arbutin (the main hydroquinone-type compound in one analysis). Arbutin is turned into hydroquinone in the body and in urine, the basis of bearberry's antiseptic action. The amount of arbutin in heather products is unknown. For uva ursi, authors linked to the industry judged recommended use safe, and EU rules limit it to short courses and exclude people with kidney disease, pregnancy and breastfeeding. Whether the same limits fit heather has not been tested; they are a sensible precaution only. Systematic review 11 8 9 13
- Pregnancy and breastfeeding: avoid. The consumer drug reference says there is not enough reliable information and advises avoiding heather in pregnancy and breastfeeding. Authoritative guidance 15
- Kidney disease, water pills, lithium: ask first. No study has tested heather in kidney disease or alongside medicines. If heather does act as a diuretic, as tradition claims, it could in theory matter for kidney disease, for water pills, and for lithium, whose blood level depends on kidney handling of salt and water. This is theory only, not a reported interaction. If you have kidney disease or take such medicines, talk to your doctor or pharmacist before using heather. Theory
Side effects 2
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Lung inflammation from workplace dust (hypersensitivity pneumonitis) A broom maker breathing heather dust for months. This is about occupational dust, not tea. | One case report | serious (treated in hospital; she recovered) Almost complete recovery with prednisolone | Case report 1 |
| Side effects of heather tea or supplements The reference says no side effects have been reported, but also that safety has not been properly assessed. | None reported; likely rarely looked for | unknown unknown | Authoritative guidance 15 |
Liver
No case of liver injury linked to heather was found in the searches done, and no LiverTox entry for heather was found (a bookshelf search returned unrelated hits and was not followed up). This is absence of evidence, not proof of safety.
How often. Not known.
Monitoring. None advised by any source found.
This is a safety connection. It is not evidence that Heather supports liver health.
Medicines and supplements 3
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Water pills (diuretics), lithium, kidney-affecting medicines prescription | Theory: a diuretic plant could add to a drug effect on fluid and salt balance. Heather has not been shown to be a diuretic. | Unknown; no case or study found. | Theory Not enough evidence | Ask a doctor or pharmacist before combining, especially with lithium. |
| Antidepressants and other MAO-related medicines prescription | Lab: a heather water extract blocked the MAO-A enzyme in a test tube. | Unknown; shown only in an enzyme assay. | Laboratory research Not enough evidence 4 | Ask a pharmacist before combining with antidepressants. |
| Other bearberry/arbutin products (uva ursi, pipsissewa) herb | Theory: stacking products that all release hydroquinone adds exposure. | Unknown. | Theory Not enough evidence 11 | Do not stack several arbutin-containing herbs. |
Who should check first 3
| Situation | Advice | Evidence |
|---|---|---|
| Pregnancy and breastfeeding | Avoid; not enough reliable information. | Authoritative guidance 15 |
| Kidney disease | Do not self-treat. Related bearberry is contraindicated in kidney disease in the EU (second-hand, not re-read); heather has no data. | Theory 13 |
| Possible urinary infection with fever, back pain or blood in urine | Seek medical care instead of herbal tea. | Controlled trial 3 |
Overdose, product quality and regulators
Summary. No human toxicity data on heather were found. Lab tests suggest low acute toxicity for most of eight plant extracts, but some were toxic to normal cells.
Animal. One brine-shrimp test: LC50 above 400 mg/L for most of eight extracts (abstract does not give heather separately).
Human doses studied. None.
High dose or long term signals. None found; not studied.
Overdose response. None found.
Genotoxicity. Not found.
Toxic plant parts. No toxic part reported in the sources read. Arbutin has low acute and chronic toxicity in a review of the single compound.
No survey of heather products for adulteration, heavy metals or pesticides was found, so quality is unknown rather than known to be good.
Name confusion. "Heather" and "heath" names cover other plants, including Erica species. The consumer reference lists Erica vulgaris as a synonym. Heather honey is a different product with its own research. Not verified from a botanical source here. 15
Arbutin content varies. No arbutin amounts for commercial heather products were found. 9
| Body | Action | Date |
|---|
When to get medical help
- Fever, shivering, back or flank pain, vomiting or blood in the urine
- Burning or frequent urination lasting more than a couple of days or coming back
- Trouble breathing, cough or fever after breathing plant dust
- Swelling, rash or breathing trouble after a first use (possible allergy)
Stop the supplement and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
What is heather tea used for?
Does heather treat a urinary tract infection?
Is heather a proven diuretic?
No. It is called a diuretic in tradition, but we found no study that measured urine output.
Is there human research on heather?
We found no clinical trial. The research is lab and animal work, plus reviews.
What is arbutin?
Is heather safe in pregnancy or breastfeeding?
Not enough reliable information. The reference we read advises avoiding it.
Can people with kidney disease use heather?
Does heather interact with medicines?
No interaction studies exist. In theory a diuretic plant could matter with water pills or lithium, and a lab test found it blocks the MAO-A enzyme. Ask a pharmacist.
Does heather help anxiety or low mood?
Is heather the same as heather honey?
No. Heather honey is a different product and was not the subject of the studies cited here.
When should I see a doctor?
For fever, back or flank pain, vomiting, blood in the urine, or urinary symptoms that do not clear quickly or keep returning. A herbal tea should not replace care.
How much should I take?
No amounts have been established for heather. Ask a doctor or pharmacist.
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Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against PubMed records.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-25
- Last substantive update
- 2026-10-25
- How we research
- We read the nutrient summary we hold, searched PubMed, checked GBIF and PubChem, and tried EMA, NCCIH and NLM pages (none found for heather). Only abstracts were read for papers. The Natural Medicines reference was read as a web page. EU rules for bearberry are second-hand. Certainty ratings are our own reading. No study is cited that we could not verify.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown.
Sources 16
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Aydemir Y, Güngen AC, Çoban H. Hypersensitivity pneumonitis caused by the broom grass (Calluna vulgaris). Respiratory Medicine Case Reports. 2015. PMID 26236625. DOI 10.1016/j.rmcr.2015.06.001. (abstract)
- Cucu AA, Baci GM, Cucu AB, Dezsi S, Lujerdean C, Hegedus IC, Bobis O, Moise AR, Dezmirean DS. Calluna vulgaris as a Valuable Source of Bioactive Compounds: Exploring Its Phytochemical Profile, Biological Activities and Apitherapeutic Potential. Plants (Basel). 2022. PMID 35956470. DOI 10.3390/plants11151993. (abstract)
- Gágyor I, Hummers E, Schmiemann G, Friede T. Herbal treatment with uva ursi extract versus fosfomycin in women with uncomplicated urinary tract infection in primary care: a randomized controlled trial. Clinical Microbiology and Infection. 2021. PMID 34111592. DOI 10.1016/j.cmi.2021.05.032. (abstract)
- Jäger AK, Gauguin B, Andersen J, Adsersen A, Gudiksen L. Screening of plants used in Danish folk medicine to treat depression and anxiety for affinity to the serotonin transporter and inhibition of MAO-A. Journal of Ethnopharmacology. 2013. PMID 23266274. DOI 10.1016/j.jep.2012.12.021. (abstract)
- Martins de Deus B, Fernandes C, Molina AK, Xavier V, Pires TCSP, Mandim F, Heleno SA, Finimundy TC, Barros L. Chemical Characterization, Bioactivity and Toxicity of European Flora Plant Extracts in Search for Potential Natural Origin Preservatives. Plants (Basel). 2023. PMID 37570937. DOI 10.3390/plants12152784. (abstract)
- Nahar L, Al-Groshi A, Kumar A, Sarker SD. Arbutin: Occurrence in Plants, and Its Potential as an Anticancer Agent. Molecules. 2022. PMID 36557918. DOI 10.3390/molecules27248786. (abstract)
- Olteanu ED, Filip A, Clichici S, Daicoviciu D, Achim M, Postescu ID, Bolfa P, Bolojan L, Vlase L, Muresan A. Photochemoprotective effect of Calluna vulgaris extract on skin exposed to multiple doses of ultraviolet B in SKH-1 hairless mice. Journal of Environmental Pathology, Toxicology and Oncology. 2012. PMID 23339698. DOI 10.1615/jenvironpatholtoxicoloncol.v31.i3.50. (abstract)
- Siegers C, Bodinet C, Ali SS, Siegers CP. Bacterial deconjugation of arbutin by Escherichia coli. Phytomedicine. 2003. PMID 12807345. DOI 10.1078/1433-187x-00301. (abstract)
- Starchenko G, Hrytsyk A, Raal A, Koshovyi O. Phytochemical Profile and Pharmacological Activities of Water and Hydroethanolic Dry Extracts of Calluna vulgaris (L.) Hull. Herb. Plants (Basel). 2020. PMID 32549372. DOI 10.3390/plants9060751. (abstract)
- Vučić DM, Petković MR, Rodić-Grabovac BB, Stefanović OD, Vasić SM, Comić LR. In vitro activity of heather [Calluna vulgaris (L.) Hull] extracts on selected urinary tract pathogens. Bosnian Journal of Basic Medical Sciences. 2014. PMID 25428676. DOI 10.17305/bjbms.2014.40. (abstract)
- de Arriba SG, Naser B, Nolte KU. Risk assessment of free hydroquinone derived from Arctostaphylos Uva-ursi folium herbal preparations. International Journal of Toxicology. 2013. PMID 24296864. DOI 10.1177/1091581813507721. (abstract)
- . Callunae herba (Altmeyers Encyclopedia of Naturopathy). . . (summary-only)
- . EU herbal monograph and assessment reports, Arctostaphylos uva-ursi folium (EMA/HMPC). . . (summary-only)
- . GBIF Backbone: Calluna vulgaris (L.) Hull. . . (full-text)
- . Heather (Natural Medicines monograph, shown via vital.ly). . . (full-text)
- Šukele R, Skadiņš I, Koka R, Bandere D. Antibacterial effects of oak bark (Quercus robur) and heather herb (Calluna vulgaris L.) extracts against the causative agents of bovine mastitis. Veterinary World. 2022. PMID 36341072. DOI 10.14202/vetworld.2022.2315-2322. (abstract)