# Plant Monograph: Calendula
**Name of plant:**
Calendula
**Catch phrase (Carmina Gadelica or traditional invocation if available):**
**“Marigold, flower of the sun.”**
No specific Carmina Gadelica invocation for *Calendula officinalis* has been identified. The traditional association of calendula with the sun, warmth, protection and healing is widespread in European folk practice.
**Family:**
Asteraceae
**Genus and species:**
*Calendula officinalis* L.
**Other names:**
* Calendula
* Pot marigold
* Common marigold
* Garden marigold
* English marigold
* Marybud
* Marygold
* Golds
* Scotch marigold
* Bride of the Sun
* Calendula flower
* *Flos Calendulae*
**Brief introduction:**
Calendula is an aromatic annual or short-lived perennial herb native to the Mediterranean region and widely cultivated throughout Europe and elsewhere. It bears bright yellow to orange flower heads and is particularly valued for its long flowering season.
Unlike the ornamental African and French marigolds of the genus *Tagetes*, medicinal calendula is *Calendula officinalis*. Its flowers have a long history in European folk medicine, where they were employed particularly for wounds, inflammation, skin complaints and digestive preparations.
The flower is recognized in European herbal medicine for traditional topical use in minor skin inflammation and minor wounds, and for minor inflammation of the mouth and throat.
**Traditional uses:**
* Applied to minor wounds, cuts, abrasions and irritated skin.
* Used for burns, sunburn and inflammatory skin conditions.
* Used as a wash or infusion for inflammation of the mouth and throat.
* Used traditionally as a digestive and mild bitter.
* Used in folk medicine for menstrual complaints and other inflammatory conditions.
**Historical use:**
* Calendula flowers were used in European household medicine for wounds and inflamed skin.
* The flowers were incorporated into salves, ointments and infused oils.
* Calendula preparations were used traditionally as washes for sores and irritated tissues.
* Flowers were employed as a culinary and medicinal colouring agent.
* Calendula became a common ingredient in European herbal preparations intended for the skin and digestive system.
**Parts used and method of use:**
* Flower heads, particularly the ray florets and flowering tops.
* Dried flowers and extracts prepared from the flowers.
Used as:
* Infusion for topical washes, compresses and mouth rinses.
* Oil infusion incorporated into salves, balms and creams.
* Tincture or liquid extract for topical preparations.
* Dried flower used in traditional herbal teas and compound preparations.
**Use in healing (modern herbal practice):**
* Topical support for minor wounds and superficial skin irritation.
* Traditional treatment of minor inflammatory skin conditions, including mild sunburn.
* Traditional topical treatment of minor inflammation of the mouth and throat.
* Used in creams, ointments and infused oils intended to soothe irritated skin.
* Investigated for wound healing, anti-inflammatory and antimicrobial activity.
The EMA recognizes calendula flower preparations for minor skin inflammation, minor wounds and minor mouth/throat inflammation on the basis of long-standing traditional use. It specifically notes that clinical studies have been conducted but that methodological limitations prevent firm conclusions regarding efficacy.
**Pharmacology and biochemistry:**
* **Flavonoids** — including quercetin and isorhamnetin glycosides.
* **Triterpenoid saponins and triterpenoid alcohols** — important constituents of calendula flower.
* **Carotenoids and essential-oil constituents** — contribute to the characteristic yellow-orange colour and biological activity.
Mechanisms:
* Flavonoids and triterpenoids demonstrate anti-inflammatory activity through modulation of inflammatory signalling pathways.
* Calendula extracts demonstrate antioxidant activity and may influence oxidative processes involved in tissue injury.
* Experimental studies suggest effects on fibroblast activity, granulation tissue and other processes involved in wound repair.
**Overall profile:**
Calendula is a **mild, primarily topical anti-inflammatory and vulnerary herb** with a long European history of use. Its phytochemicals demonstrate anti-inflammatory, antioxidant and antimicrobial activities in laboratory studies. Human evidence remains limited, but the traditional topical applications are sufficiently established for recognition in European herbal medicine.
**Common dosage:**
* **Topical infusion:** 1–2 g dried flowers per 150 mL water; use as a wash, compress or rinse.
* **Liquid extract, DER 1:1:** preparations equivalent to approximately 2–10% herbal substance in semi-solid topical products.
* **Oil extract, DER 1:10:** equivalent to approximately 2–8% herbal substance in semi-solid preparations.
* **Ointment:** preparations equivalent to approximately 4–20% herbal substance.
**Safety factors (including side effects):**
* Calendula is generally regarded as well tolerated when used appropriately, particularly topically.
* Allergic or sensitizing skin reactions can occur.
* People allergic to plants of the **Asteraceae/Compositae family** should avoid calendula preparations.
* Avoid application to serious, deep, infected or extensively damaged wounds without appropriate medical assessment.
* Safety data for prolonged internal medicinal use are less established than for traditional topical applications.
* Pregnancy and breastfeeding: medicinal internal use should be approached cautiously because adequate safety data are limited.
**First aid / adverse reaction response:**
* **Mild skin irritation:** discontinue use and wash the affected area.
* **Contact dermatitis or rash:** discontinue use and seek medical advice if symptoms persist or become extensive.
* **Swelling, hives or other allergic symptoms:** discontinue use and seek medical advice.
* **Difficulty breathing, facial swelling or severe allergic reaction:** seek emergency medical care immediately.
* **Worsening or non-healing wound:** discontinue self-treatment and obtain appropriate medical assessment.
**Drug interactions:**
* No major clinically established drug interactions are well documented for ordinary topical calendula preparations.
* Theoretical interactions have been proposed with medicines affecting inflammation or immune function, but clinical significance is uncertain.
* Internal medicinal preparations should be distinguished from topical calendula because systemic exposure is substantially different.
* Individuals taking multiple medications should consult a pharmacist or qualified practitioner before prolonged internal use.
**Horticultural requirements:**
* **USDA / Canadian zone:** Generally grown as an annual in Canada; can behave as a short-lived perennial in approximately USDA zones 8–10.
* **Soil pH:** Approximately 6.0–7.5; tolerates moderately alkaline soil.
* **Light requirements:** Full sun to partial shade.
* **Moisture:** Moderate moisture; prefers well-drained soil and does not tolerate prolonged waterlogging.
**Other notes (growth habit, harvest timing, etc.):**
* **Growth habit:** Upright, branching annual or short-lived perennial, generally 30–60 cm tall.
* **Flowering/fruiting:** Produces conspicuous yellow to orange flower heads over a long season, particularly from late spring through autumn.
* **Harvest timing:** Flower heads are harvested when fully open, preferably during dry weather; repeated harvesting encourages continued flowering.
* **Habitat:** Mediterranean-origin plant now naturalized and cultivated throughout many temperate regions.
* **Propagation/cultivation notes:** Easily propagated from seed. Direct sowing is generally successful. Deadheading encourages continued flowering. Calendula performs well in ordinary garden soil and is particularly useful in herb gardens because flowers can be harvested repeatedly throughout the season.
**Sampling of clinical reports / studies:**
* **Clinical evidence:** Human studies have investigated calendula preparations for wound healing, burns and inflammatory skin conditions, but methodological limitations have prevented firm conclusions regarding efficacy.
* **Pharmacological study:** Experimental research demonstrates anti-inflammatory, antioxidant and antimicrobial activity in calendula extracts.
* **Phytochemical study:** Calendula flowers contain flavonoids, triterpenoid saponins, carotenoids, triterpenoids and volatile constituents contributing to their biological activity.
* **Safety research:** A safety assessment found calendula extracts to be relatively nontoxic in acute animal studies, with generally low irritation and sensitization in the tested preparations; however, the authors noted limitations in extrapolating safety between different extracts and formulations.
* **Ethnobotanical evidence:** Calendula has a substantial European history as a wound, skin and inflammatory remedy and remains recognized for these traditional applications by European herbal authorities.
* **Overall assessment of evidence:** **Strong traditional evidence for topical use; promising pharmacological evidence for anti-inflammatory and wound-supporting activity; limited and methodologically inconsistent clinical evidence. Calendula is best regarded as a gentle topical herbal remedy rather than a proven systemic medicine.**
Educational Use Only: The information presented on this page is provided for educational, historical, and informational purposes only. ArdNemeton na Tuatha and Bhùth Draoi do not provide medical advice. Always consult your physician and pharmacist before using any herb, mushroom, supplement, or botanical product for medicinal purposes. Traditional uses described herein do not constitute medical claims.