Calendula, Marigold : Safety and Interactions

by MedlinePlus

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Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

People with allergies to plants in the Aster/Compositae family such as ragweed, chrysanthemums, marigolds and daisies are more likely to have an allergic reaction to calendula. There is one case of a severe allergic reaction (anaphylactic shock) after gargling with a calendula preparation.

Side Effects and Warnings

Aside from allergic reactions, few severe reactions have been found in published reports. In one small animal study, calendula was associated with a fatal reduction in blood glucose, accompanied by decreased serum lipids and protein. Skin (atopic dermatitis) and eye irritation have been reported.

Pregnancy & Breastfeeding

It is not clear if calendula is safe for use during pregnancy or breastfeeding. In animal studies, calendula has had effects on the uterus, and calendula has traditionally been thought to have harmful effects on sperm and to cause abortions. However, it is not clear if these effects occur with use of calendula on the skin.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

In early animal studies, high doses of calendula were reported to cause drowsiness. It is not clear if use of calendula on the skin of humans has this effect. In theory, use of calendula in combination with sedative drugs may lead to increased drowsiness. Examples include benzodiazepines such as lorazepam (Ativan®) or diazepam (Valium®), barbiturates such as phenobarbital, narcotics such as codeine, some antidepressants, and alcohol. Caution is advised while driving or operating machinery.

In early animal studies, high doses of calendula preparations were reported to lower blood pressure. It is not clear if use of calendula on the skin of humans has this effect. In theory, use of calendula in combination with drugs that lower blood pressure may lead to increased effects.

Other possible interactions include increases in the activity of hypoglycemic (diabetic) medications or insulin, or agents that decrease lipids and triglycerides (cholesterol-lowering drugs.)

Interactions with Herbs and Dietary Supplements

In early animal studies, high doses of calendula were reported to cause drowsiness. It is not clear if use of calendula on the skin of humans has this effect. Use of calendula in combination with herbs or supplements that have possible sedative effects may lead to increased drowsiness. Examples include: calamus, California poppy, capsicum, catnip, celery, couch grass, dogwood, elecampane, German chamomile, goldenseal, gotu kola, hops, kava (may help sleep without drowsiness), lavender aromatherapy, lemon balm, sage, sassafras, skullcap, shepherd's purse, Siberian ginseng, St. John's wort, stinging nettle, valerian, wild carrot, wild lettuce, withania root, and yerba mansa. Caution is advised while driving or operating machinery.

In early animal studies, high doses of calendula preparations were reported to lower blood pressure. It is not clear if use of calendula on the skin of humans has this effect. In theory, use of calendula in combination with herbs that may lower blood pressure may lead to increased effects. Examples include aconite/monkshood, arnica, baneberry, betel nut, bilberry, black cohosh, bryony, California poppy, coleus, curcumin, eucalyptol; eucalyptus oil, ginger, goldenseal, green hellebore, hawthorn, Indian tobacco, jaborandi, mistletoe, night blooming cereus, oleander, pasque flower, periwinkle, pleurisy root, shepherd's purse, Texas milkweed, turmeric, and wild cherry.

Other possible interactions include increases in the activity of hypoglycemic (diabetic) medications or insulin, or agents that decrease lipids and triglycerides (cholesterol-lowering agents).

Since the stem and leaves of calendula contain lutein and beta-carotene, a possible supplement interaction exists with products that contain these ingredients.

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