Calendula (Calendula officinalis L.) or marigold has been suggested to benefit in minor
wounds, skin infections, burns, bee stings, sunburn, warts, and cancer. Some animal studies
support its wound-healing claims. Side effects of calendula may include allergies, dermatitis,
serum glucose, lipid and protein reduction. High doses of calendula may cause drowsiness.
Thus, it may interact with narcotics, antidepressants, and blood pressure and glucose
lowering agents.

Calendula Officinalis reported to contain sugars, carotenoids, phenolic acids, sterols,
saponins, flavonoids, resins, sterins, quinones, mucilages, vitamins, polyprenylquinones, and
essential oils.. Acute toxicity studies in rats and mice indicate that the extract is relatively
nontoxic. Animal tests showed at most minimal skin irritation, and no sensitization or
phototoxicity. Clinical testing of cosmetic formulations containing the extract elicited little
irritation or sensitization.

Calendula shows benefits on inflammatory conditions.
Calendula combined with Symphitum showed benefit in stomach inflammation according to a
study of 170 patients. The effects of the combined herbs on gastric acidity, ulcer is
comparable to antacids' in the study. [3]

Germany, researchers noticed that the flower heads of Calendula officinalis contains
anti-inflammatory triterpenoid esters including faradiol 3-O-laurate, palmitate and myristate. [4]

Calendula extracts shows benefits in muscle spasm, according to an in vitro study.
In rabbit jejunum, extract of Calendula officinalis flowers caused a dose-dependent (0.03-3.0
mg/mL) relaxation of spontaneous and K+-induced contractions, suggestive of calcium
channel blockade (CCB).  The aqueous fraction exhibited a significant atropine sensitive
spasmogenic effect. These data indicate that the Calendula officinalis flowers extract
contains spasmolytic and spasmogenic constituents, via calcium channel blocking and
cholinergic activities. [1]

Calendula has anti-viral activities.
Italian researchers demonstrated anti-viral activities of gycosides extracted from the aerial
parts of Calendula arvensis. . All the compounds were able to inhibit vesicular stomatitis virus
infection. [5]

Researchers from Venezuela examined extracts of dried flowers from Calendula officinalis for
its inhibitory effects on the human immunodeficiency virus type 1 (HIV-1) replication using
vitro MTT/tetrazolium-based assay. They found that Calendula officinalis flowers caused a
significant dose- and time-dependent reduction of HIV-1 reverse transcription (RT) activity. [6]

Researchers from Lebanon reported Calendula officinalis had an immunomodulation effect
against three different live viruses in broiler chickens. [11]

Calendula shows benefits on wounds and other skin conditions.
A study of 34 patients with venous leg ulcers demonstrated the benefits of marigold
(Calendula officinalis) ointment on venous ulcer epithelialization. In the study, the ointment
was applied twice a day for three weeks. [7]

French researchers suggested that Calendula is highly effective for the prevention of acute
dermatitis of grade 2 or higher and should be proposed for patients undergoing
postoperative irradiation for breast cancer. Their claim is based on a study of 254 patients
conducted between July 1999 and June 2001. They found that the occurrence of acute
dermatitis of grade 2 or higher was significantly lower (41% v 63%; P <.001) with the use of
calendula than with trolamine. [12]

Calendula extracts show anti-cancer effects in in vitro studies.
French researchers demonstrated antimutagenic activity of saponins extracted from
Calendula officinalis and C. arvensis using a modified liquid incubation technique of the
Salmonella/microsomal assay. [8]

Researchers from Universidad de Granada, Spain, demonstrated the anti-cancer effects of
Calendula officinalis extracts on tumor cell lines derived from leukemias, melanomas,
fibrosarcomas, breast, prostate, cervix, lung, pancreas and colorectal cancers. The inhibition
ranged from 70 to 100%. Mechanisms of inhibition were identified as cell cycle arrest in
G0/G1 phase and Caspase-3-induced apoptosis. [9]

Researchers from Mexico showed the benefits of Calendula officinalis flower extracts on liver
cancers in a rat study. [10]


[1] Bashir S, et al, Studies on spasmogenic and spasmolytic activities of Calendula officinalis flowers. Phytother
Res. 2006 Aug 14[2] Final report on the safety assessment of Calendula officinalis extract and Calendula
officinalis. Int J Toxicol. 2001;20 Suppl 2:13-20. [3] Chakurski I, et al, Treanntment of duodenal ulcers and
gastroduodenitis with a herbal combination of Symphitum officinalis and Calendula officinalis with and without
antacidsVutr Boles. 1981;20(6):44-7. [4] Hamburger M, et al, Preparative purification of the major
anti-inflammatory triterpenoid esters from Marigold (Calendula officinalis). Fitoterapia. 2003 Jun;74(4):328-38.
[5] De Tommasi N, et al, Structure and in vitro antiviral activity of sesquiterpene glycosides from Calendula
arvensis. . J Nat Prod. 1990 Jul-Aug;53(4):830-5. [6] Kalvatchev Z, et al, Anti-HIV activity of extracts from
Calendula officinalis flowers. Biomed Pharmacother. 1997;51(4):176-80. [7] Duran V, et al, Results of the clinical
examination of an ointment with marigold (Calendula officinalis) extract in the treatment of venous leg ulcers. Int
J Tissue React. 2005;27(3):101-6. [8] Elias R, et al, Antimutagenic activity of some saponins isolated from
Calendula officinalis L., C. arvensis L. and Hedera helix L. Mutagenesis. 1990 Jul;5(4):327-31. [9]
Jimenez-Medina E, et al, A new extract of the plant Calendula officinalis produces a dual in vitro effect: cytotoxic
anti-tumor activity and lymphocyte activation. BMC Cancer. 2006 May 5;6:119. [10] Barajas-Farias LM, et al, d
opposite effect of Calendula officinalis flower extract: chemoprotector and promoter in a rat hepatocarcinogenesis
model. Planta Med. 2006 Feb;72(3):217-21. [11] Barbour EK, et al, Evaluation of homeopathy in broiler chickens
exposed to live viral vaccines and administered Calendula officinalis extract. Med Sci Monit. 2004
Aug;10(8):BR281-5. Epub 2004 Jul 23. [12] Pommier P, et al, Phase III randomized trial of Calendula officinalis
compared with trolamine for the prevention of acute dermatitis during irradiation for breast cancer. J Clin Oncol.
2004 Apr 15;22(8):1447-53.
Calendula (Calendula officinalis L.), Marigold Benefits
and Side Effects
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