Health Guide


What is it?

Calamus is an herbal medicine used to treat heartburn, bloating, upset stomach (nausea), belly cramping, and constipation. It may also be used to increase your appetite. Calamus has not been studied in humans and the different types of Calamus are often confused. Because of this, Calamus use is not suggested.

Other names for Calamus include: Acorus, Sweet root, Sweet myrtle, Sweet sage, and Sweet flag.

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement)
  • are pregnant or plan to become pregnant while using this medicine
  • are breastfeeding
  • have any other health problems, such as high blood pressure or heart or blood vessel disease


Talk with your caregiver about how much Calamus you should take. The amount depends on the strength of the medicine and the reason you are taking Calamus. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.

Drug and Food Interactions:

Do not take Calamus without talking to your doctor first if you are taking:

  • Amphetamines (stimulants, examples: dextroamphetamine, methamphetamine) (2)
  • Medicines to help you relax or sleep (barbiturates, examples: Seconal(R) secobarbital, Nembutal(R) phenobarbital) (2,3-7)
  • Cannabis (marijuana) (8)
  • Ethanol (alcohol) (4,6)
  • Scopolamine (Transderm Scop(R)) (4)


Calamus use is not recommended because the types are hard to identify (9).

Side Effects:

Stop taking your medicine right away and talk to your doctor if you have any of the following side effects. Your medicine may be causing these symptoms which may mean you are allergic to it.

  • Breathing problems or tightness in your throat or chest
  • Chest pain
  • Skin hives, rash, or itchy or swollen skin

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • Vomiting (throwing up) (10)


1. Newall CA, Anderson LA & Phillipson JD: Herbal Medicines: A Guide for Healthcare Professionals. The Pharmaceutical Press, London, England; 1996.

2. Panchal GM, Venkatakrishna-Bhatt H, Doctor RB et al: Pharmacology of Acorus calamus L. Indian J Exp Biol 1989; 27(6):561-567.

3. Liao JF, Huang SY, Jan YM et al: Central inhibitory effects of water extract of Acori graminei rhizoma in mice. J Ethnopharmacol 1998; 61(3):185-193.

4. Nishiyama N, Zhou Y, Takashina K et al: Effects of DX-9386, a traditional Chinese medicinal preparation, on passive and active avoidance performances in mice. Biol Pharm Bull 1994a; 17(11):1472-1476.

5. Martis G, Rao A & Karanth KS: Neuropharmcological activity of Acorus calamus. Fitoterapia 1991; 62(4):331-337.

6. Dandiya PC & Sharma JD: Studies on Acorus calamus. V. Pharmacological actions of asarone and beta-asarone on central nervous system. Indian J Med Res 1962; 50:46-60.

7. Dandiya PC, Cullumbine H & Sellers EA: Studies on Acorus calamus. IV. Investigations on mechanism of action in mice. J Pharmacol Exp Ther 1959; 126:334-337.

8. Zanoli P, Avallone R & Baraldi M: Sedative and hypothermic effects induced by beta-asarone, a main component of Acorus calamus. Phytother Res 1998; 12(Supp 1):S114-S116.

9. McGuffin M, Hobbs C, Upton R et al (eds): American Herbal Products Association's Botanical Safety Handbook. CRC Press, Boca Raton, FL; 1997.

10. Vargas CP, Wolf LR, Gamm SR et al: Getting to the root (Acorus calamus) of the problem (letter). J Toxicol Clin Toxicol 1998; 36(3):259-260.

Last Updated: 1/27/2017
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