Background

Blue flag is a plant. People use the underground stem (rhizome) of blue flag to make medicine.

People use blue flag for conditions such as bloating, swelling (inflammation), fluid retention, liver problems, and many others, but there is no good scientific evidence to support these uses. Using blue flag can also be unsafe.

Safety Safety definitions

When taken by mouth: Blue flag is LIKELY UNSAFE. It can cause nausea and vomiting, and the fresh root can irritate the mouth, throat, digestive tract, and skin. Blue flag can also cause headache and swollen, watery eyes.

Special Precautions & Warnings:

Blue flag is LIKELY UNSAFE for anyone to use, but it is especially unsafe for people with any of the following conditions:

Pregnancy and breast-feeding: Blue flag is LIKELY UNSAFE. Don't use it if you are pregnant or breast-feeding.

Stomach or intestinal problems such as infections, ulcerative colitis, and Crohn's disease: Blue flag can irritate the stomach and intestines and should not be used by anyone with any of these conditions.

Effectiveness

Dosing & administration

The appropriate dose of blue flag depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for blue flag. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Interactions with pharmaceuticals

Digoxin (Lanoxin)

Interaction Rating=Major Do not take this combination.

Blue flag is a type of laxative called a stimulant laxative. Stimulant laxatives can decrease potassium levels in the body. Low potassium levels can increase the risk of side effects of digoxin (Lanoxin).

Warfarin (Coumadin)

Interaction Rating=Moderate Be cautious with this combination.

Blue flag can work as a laxative. In some people blue flag can cause diarrhea. Diarrhea can increase the effects of warfarin and increase the risk of bleeding. If you take warfarin do not to take excessive amounts of blue flag.

Water pills (Diuretic drugs)

Interaction Rating=Moderate Be cautious with this combination.

Blue flag is a laxative. Some laxatives can decrease potassium in the body. "Water pills" can also decrease potassium in the body. Taking blue flag along with "water pills" might decrease potassium in the body too much.

Some "water pills" that can decrease potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), hydrochlorothiazide (HCTZ, Hydrodiuril, Microzide), and others.

Interactions with herbs & supplements

Horsetail: Blue flag can cause the body to lose potassium. Horsetail can also cause the body to lose potassium. There is a concern that using these two herbs together might cause the body to lose too much potassium. Avoid this combination.
Licorice: Blue flag can cause the body to lose potassium. Licorice can also cause the body to lose potassium. There is a concern that using these two herbs together might cause the body to lose too much potassium. Avoid this combination.
Stimulant laxative herbs: Blue flag can cause the body to lose potassium. Herbs that act as stimulant laxatives can also cause the body to lose potassium. There is a concern that using blue flag along with any of the stimulant laxative herbs might cause the body to lose too much potassium. Avoid this combination. Other stimulant laxative herbs include aloe, alder buckthorn, black root, butternut bark, colocynth, European buckthorn, fo-ti, gamboge, gossypol, greater bindweed, jalap, manna, Mexican scammony root, rhubarb, senna, and yellow dock.

Interactions with foods

There are no known interactions with foods.

Action

There isn't enough information to know how blue flag works.