Blue Cohosh

Caulophyllum thalictroides  (Berberidaceae).  Commonly known as blue cohosh.

Caulophyllum, being indigenous to the United States, was used by at least ten tribes of Native Americans.  They used it to promote menstruation and for delayed birth and as a contraceptive.  It was also used for quite a variety of other medical complaints.

Caulophyllum is a perennial, up to three feet tall with thrice-divided, bluish green leaves that give it the name blue cohosh. The greenish yellow flowers appear before the leaves unfold.  It has a dark blue, pea sized, berry-like fruit.  It grows in deciduous woods and along the moist banks of streams, from New Brunswick to the Southern United States.

The root is the part of the plant used.  Caulophyllum is available as a bulk herb, capsules and hydroalcoholic extract.  It is frequently mixed with other herbs, such as Cimicifuga.

There are a number of alkaloids contained in Caulophyllum, methylcytisine considered one of the most important.  The action of methylcytisine is similar to nicotine in that it binds to the same receptors in the central nervous system, elevates blood pressure and stimulates both respiration and intestinal motility.  Methylcytisine is only about 1/40 as toxic as nicotine.¹ There are quinolizidine alkaloids have been implicated as teratogens in higher animals.  Their toxicity to range animals, especially sheep is well documented.²

There are oxytocic effects from Caulophyllum as well.  The glycoside caulosaponin is considered responsible for this effect, as it has been found to be a uterine stimulant. Caulosaponin also constricts coronary blood vessels and exerts a toxic effects on cardiac muscles.³

Commonly Caulophyllum is used for menstrual irregularities and menopausal complaints, usually combined with Cimicifuga.  It is used to stimulate and strengthen contractions and hasten labor.  It is also used as an antispasmodic for such things as colic, asthma, bronchitis and nervous coughs. It has also been used for rheumatic pain.⁴

There are a number of alkaloids present in Caulophyllum including a variety of quinolizidine alkaloids: methylcytisine, bapifoline and anagyrine.  It also contains the aporphine alkaloid magnoflorine. There are other minor tertiary alkaloids.⁵  There is the glycoside caulosaponin and various resins, phytosteroids, phosphoric acid, potassium, magnesium, calcium, iron, silicon and phosphorus.

There has not been enough scientific evidence to establish dosage guidelines.  The popular herbal texts offer quite a variation of recommended dosages.  A water decoction is often recommended, but as the plant is high in alkaloids and resins, a hydroalcoholic extract or capsule is probably more chemically active.  Hoffmann and Willard recommend conservatively at ½  to 1 ounce bulk root, decocted and taken at intervals of three or four times a day, and 1-2 ml three times a day of the hydroalcoholic extract.^6 7

Some authors of popular herbals recommend up to three times this amount.  The smaller dosages seem the wisest course of action, as there is the potential of toxicity with the herb.  There is a case on record of a pregnant woman taking Caulophyllum in the last month before delivery at three times the dosage recommended by her midwife.  Her baby was born with acute myocardial infarction associated with profound congestive heart failure and shock.  The baby eventually recovered.⁸

Caulophyllum taken in the last months of pregnancy and to induce labor should only be done with professional supervision. Do not take during pregnancy at any point without medical supervision.  Do not take more than the recommended dose.  Do not take when nursing.

There is a possibility that it could react with heart and blood pressure medications. The alkaloid, methylcytisine and the vasoactive glycoside caulosaponin can cause hypertension and cardiac toxicity. Large doses of up to three times the normal produce nausea, vomiting and gastritis. Larger doses of both root and uncooked berries causes headache, thirst, dilated pupils, muscle weakness, uncordination, cardiovascular collapse and convulsions.⁹