Blue Flag Herb – Uses And Side Effects

blue flag

Used by Native Americans to induce vomiting and treat constipation, blue flag comes from Iris versicolor, a perennial found abundantly in swamps and 10 areas in eastern and central North America. When the plant isn’t In bloom, many people mistake it for sweet flag (Acorus calamus).

The herb’s rhizome (underground stem) has a peculiar odor and pungent, acrid taste. The United States Pharmacopoeia, a legal compendium of drug standards lists the rhizome of as an official pharmaceutical Ingredient.

Common doses of Blue flag

Blue flag comes as:

  • powdered root (20 grains or 1,300 milligrams)
  • solid extract (10 to 15 grains, or 650 to 975 milligrams)
  • fluid extract (0.5 to 1 fluidrams, or 2.5 to 5 milliliters)
  • tincture (1 to 3 fluidrams, or 5 to 15 milliliters)

Some experts recommend the following dose:

  • As a laxative, 10 to 20 grains of the powdered root or solid extract, or 0.5 to 3 fluidrams of the fluid extract or tincture.

Why people use Blue flag herb

  • Bruises
  • Constipation
  • Fluid retention
  • Inflammation
  • Liver disease
  • Sores
  • To induce vomiting
  • To stimulate the bowel

Side effects of Blue flag

Call your health care practitioner if you experience any of these possible side effects of blue flag:

Ingesting fresh root preparations may cause severe nausea and vomiting.


Combining herbs with certain drugs may alter their action or produce unwanted side effects. Tell your health care practitioner about any prescription or nonprescription drugs you’re taking.

Important points to remember

  • Don’t use blue flag if you’re pregnant or breast-feeding.
  • Avoid taking this herb internally.
  • Be aware that blue flag causes severe irritation if it contacts the eyes, nose, or mouth.
  • Keep all parts of this plant out of children’s reach.

What the research shows

Because blue flag is a known intestinal irritant and may pose a danger in some conditions, medical experts don’t recommend it for any disease. In fact, they advise people to avoid this herb until they know more about its risks and benefits.

Other names for Blue flag : –

Other names for blue flag include dagger flower, flag lily, liver lily, poison flag, snake lily, water lily and wild iris.

Products containing Blue flag are sold under such names as Iridin and Irisin.

Useful References

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