Calendula (Calendula officinalis L.) Dosing and Safety

safety

Allergies

Avoid if allergic or sensitive to calendula (marigold), its parts, or members of the Aster or Compositae family, such as ragweed, chrysanthemums, or daisies.
Severe allergic reaction and skin symptoms have been reported with exposure to calendula. There may be cross-sensitivity with arnica, nickel, Myroxylon pereirae resin, propolis, and colophonium.

Side Effects and Warnings

Calendula is likely safe when used as a spice, natural seasoning, or flavoring, and when used in cosmetics.
Drowsiness or sedation may occur. Use caution if taking sedatives or driving or operating heavy machinery.
Calendula may cause low blood pressure. Caution is advised in people taking drugs or herbs and supplements that lower blood pressure.
Calendula may lower blood sugar levels. Caution is advised in people with diabetes or low blood sugar, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood sugar levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.
Use cautiously in people taking agents that may affect the immune system. Calendula may enhance immune response.
Use cautiously in people who have kidney disorders. High doses of calendula (up to 5 grams per kilogram) may cause kidney problems.
Use cautiously in children, due to a lack of safety data.
Avoid in pregnant or breastfeeding women. Calendula may cause abortion.
Avoid if allergic or sensitive to calendula (marigold), its parts, or members of the Aster or Compositae family, such as ragweed, chrysanthemums, or daisies.
Avoid long-term use, due to the risk of side effects.
Avoid taking by mouth at levels above those commonly found in the diet.
Avoid injecting into a vein or the body cavity.
Calendula may also cause eye irritation, liver problems, and skin irritation.

Pregnancy and Breastfeeding

Avoid in pregnant or breastfeeding women. There is a lack of scientific evidence on the use of calendula during pregnancy or breastfeeding.

dosing

Adults (18 years and older)

Ointments or tincture compresses have been applied to affected areas as needed. The expert panels German Commission E and the European Scientific Cooperative on Phytotherapy report that a 2-5 percent ointment is often used. Calendula products may be applied 3-4 times daily as needed. A 1:1 tincture in 40 percent alcohol or 1:5 in 90 percent alcohol may be diluted at least 1:3 with freshly boiled water for compresses.
To protect skin during radiation therapy, an ointment containing calendula in a petroleum jelly base has been applied to the skin at least twice daily, for the duration of radiation treatment. Calendula ointment has been applied at the start of radiation therapy, continuing until the end of treatment.
For skin care, calendula facial creams have been applied to the face once daily for eight weeks before bed.
To treat venous leg ulcers, an ointment containing marigold extract in a neutral base has been applied to the skin twice daily for three weeks.

Children (under 18 years old)

To treat diaper rash, a calendula ointment has been applied to the skin three times daily for ten days, or stopped when healing occurred sooner than ten days.

interactions

Interactions with Drugs

Calendula may increase kidney and liver problems caused by some other drugs. High doses of calendula (up to 5 grams per kilogram) may lead to liver toxicity.
Calendula may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. People taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Calendula may cause low blood pressure. Caution is advised in people taking drugs that lower blood pressure.
Calendula may increase the amount of drowsiness caused by some drugs. Examples include benzodiazepines such as lorazepam (AtivanĀ®) or diazepam (ValiumĀ®), barbiturates such as phenobarbital, narcotics such as codeine, some antidepressants, and alcohol. Caution is advised while driving or operating machinery.
Calendula may also interact with agents that affect the immune system, agents that affect the nervous system, agents that prevent muscle spasms, agents that treat protozoan infections, agents that treat stomach disorders, antibiotics, anticancer agents, anti-gout agents, anti-inflammatory agents, antiviral agents, and cholesterol-lowering agents.

Interactions with Herbs and Dietary Supplements

Calendula may increase kidney and liver problems caused by some other herbs and supplements. High doses of calendula (up to 5 grams per kilogram) may lead to liver toxicity.
Calendula may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
Calendula may cause low blood pressure. Caution is advised in people taking herbs or supplements that lower blood pressure.
Calendula may increase the amount of drowsiness caused by some herbs or supplements.
Calendula may also interact with antibacterials, anticancer herbs and supplements, anti-gout herbs and supplements, anti-inflammatories, antioxidants, anti-parasitic herbs and supplements, antiviral herbs and supplements, beta-carotene, cholesterol-lowering herbs and supplements, herbs and supplements that affect the immune system, herbs and supplements that affect the nervous system, herbs and supplements that prevent muscle spasms, herbs and supplements that treat stomach disorders, and lutein.