Sweet flag (Acorus calamus; A. americanus) has been one of those on-again/off-again herbs where it’s safe to use it, then it’s not, and then it is again. Well good news for North Americans – its native calamus is safe and very effective for many conditions.

While known by many names – acorus, calamus, sweet flag, sweet sedge, bitterroot, myrtle grass, and grassleaf – the root is used in Western, Chinese and Ayurvedic medicines. In the West its strongly scented rhizomes have traditionally been used to make fragrances and as a spice, particularly to substitute for ginger and cinnamon. It is eaten candied, and is also used for thatching and strewing (as in on the floor).

Bitter, spicy, and aromatic, calamus is a warming carminative, antimicrobial, Phlegm-dissolving herb that also opens the mental and sensory orifices. Because of these qualities, it’s long been used medicinally for digestive problems such as dyspepsia, gas, heartburn, ulcers, nausea, motion sickness, poor appetite and peristalsis, damp-heat diarrhea and dysentery, and inflammation of the stomach lining and stomach tension.

Traditional tribes used it to increase vitality and ensure long life. It is also useful for colds, sore throat, hoarseness, laryngitis, and sinus infections. According to Chanchal Cabrera, the British herbal tradition uses calamus root as a stomach acid balancer.

Currently, calamus is used for anxiety. Many who chew on the roots find that it helps their daily emotional balance, but it also alleviates full-blown anxiety and panic attacks as well as PTSD, particularly if chewed at the beginning of an attack to forestall its occurrence. As well, it helps attention and focus for those having to pull all-nighters or who study a lot, as its aromatic oils clear perception. Jim McDonald likens it to increasing one’s “perceptual depth of field,” i.e., helping one to focus in on the details better and increasing mental clarity.

There’s a reason for these latter effects on anxiety and mental clarity. In Traditional Chinese Medicine (TCM), calamus root is an herb used to clear Phlegm misting the Heart orifices. Now whatever does that mean you might ask? Basically, the fragrance gently opens the mental and physical senses, meaning it acts like mild smelling salts. In TCM, the mind and Heart are intimately connected and clearing the heart of Phlegm blockage aids blood flow through the brain to nourish the mind so one thinks and speaks more clearly (and appropriately – as opposed to mania and withdrawal).

Dosage of American calamus:

Start with little bits, chewing 1 tsp.-1 Tbsp of the fresh or dried root;

1-4 g/day;

1 drop of essential oil under the nose;

15-60 drops tincture 3 times/day;

Uas medicated ghee, oil or milk decoction, paste and powder.


Avoid with bleeding disorders. Use caution in pregnancy.  Larger doses are emetic.

The Chinese have other uses for Acori calami (shui cheng pu) rhizome. They also consider it a warm, acrid, bitter herb that enters the Heart, Liver, and Stomach, and yet they use it to extinguish Wind as well as open the sensory orifices and transform phlegm. They use calamus (acorus is their common name) specifically to treat tremors, seizures, and loss of consciousness, As well, it moves Qi, strengthens the stomach and clears dampness obstructing digestion for treating epigastrc pain, abdominal distension, poor appetite, cough, gout, diarrhea, dysentery, scabies, wind-damp bi obstruction pain (arthritis, rheumatism and joint pain), palpitations, forgetfulness, and a greasy tongue coat, and to stop itching.

As well, the Chinese use the rhizome of Acori tatarenowii (shi chang pu), which has a similar warm energy with aromatic, acrid, and bitter flavors and enters the Heart and Stomach. Dispersing, it is used to transform damp, dissolve phlegm, open the sensory orifices, wake the Spleen and Stomach, improve digestion, and dredge congealed phlegm from the chest and diaphragm. Interestingly, calamus grows in watery areas – called “watery flourished reed” by the Chinese – and it effectively clears dampness from the body. It also moves Qi and Blood, reduces swelling, and improves overall healing. It is used for coma, mania, withdrawal, impaired mental function, deafness, forgetfulness, dysentery with inability to eat or drink, dizziness, and dulled senses. It can be taken internally and topically for wind-cold-damp bi painful obstruction, trauma, and sores.

Now here’s the important thing to remember about calamus: Chinese calamus is rich in asarone, a substance that’s carcinogenic, metagenic, chromosome damaging, and liver toxic. The Russian and European species are also high in asarone, while interestingly the central European variety has less than 10% and so doesn’t seem to have the psychoactive properties. All of these varieties can be hallucinogenic as well. For this reason, the Chinese only use acorus in acute conditions and for short periods.

However, American calamus is free of asarone and so is fine to use regularly. On the other hand, if the mind-activating properties of calamus are due to its asarones, then it may also not be as effective for these conditions. All of this needs examination as calamus has been widely used for thousands of years as medicine and food. Is this another case of an herbal witch hunt or something to be cautious of?

Ayurveda medicine is a case in point. Calamus is one of their major herbs and has been used in India for millennia. Called vacha, which means “speaking” (referring to its effects on clearing the throat), it’s been employed as a mental rejuvenative, decongestant, expectorant, nervine, antispasmodic, emetic, and energizer to treat colds, cough, asthma, sinusitis, loss of memory, and to increase mental cognition.

Interestingly, Ayurveda also uses calamus similarly as the Chinese to treat seizures, epilepsy, coma, shock, and hysteria, all Wind disorders in TCM. As well, its use for sharpening memory, enhancing awareness, and increasing communication all refer to its action on the TCM Heart and mind connection, too. As such, it can be used for autism, attention deficit disorders, and scattered thinking/awareness. All of these applications aren’t used in the West and so can expand our uses of it.

Further, calamus clears the head of kapha, a way of saying it dislodges mucus, which may result in a drippy nose as it leaves. Typically it is applied as an oil, essential oil, or medicated ghee under the nose or into the nostrils (a nasya to enter the nose’s gateway to the head, sinuses and deep lungs). And yet, taking too much or too frequently can be over-stimulating because of its warming stimulant properties. For this reason, it’s often combined with gotu kola, a cooling herb with complementary effects.

Large doses of calamus are emetic and may also be “hallucinatory,” meaning it can cause unusual thoughts that aren’t necessarily pleasant. Overall, if one sticks to the low dose of calamus, one should be fine regarding its asarones and potentially mind-altering effects.

Lastly, powdered calamus root has been used as a vermifuge and insecticide for fleas, ants and other insects.


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