The plant Acorus calamus, colloquially called sweet flag, has been used for medicinal purposes in various parts of the world for a very long time, in this case defined as pre-Biblical times. Though the fact that sweet flag's active component — beta-asarone — has been found to be carcinogenic  should give you pause, at least 10 uses for Acorus calamus (sweet flag) have been confirmed in scientific studies. It is, in this case, the plant's essential oil and rhizome extract that "do things", to help cure everything from diarrhea to pain and inflammation. [2, 3]
The finding that taking Acorus calamus in large quantities may contribute to giving you cancer is what caused the US Food and Drug Administration (FDA) to ban it , but the plant's hallucinogenic properties are no less interesting. They also lead to two questions, important to different sub-sets of society:
- Will using Acorus calamus as part of an alternative medicine regimen give me hallucinations?
- Is sweet flag something I can use as a recreational drug to get high?
Let's go down the rabbit hole!
Can I Use Sweet Flag As A Recreational Drug?
I'm old, but I've heard that "kids these days" even use regular old school glue to try to get high. The obvious answer, then, is that you could give it a try — and some people have. Since I have no personal experience, here are some interesting quotes from "Drugs Forum":
"Last weekend, I went to my local herb shop and bought an ounce of whole Calamus root. I gound it up in the blender and devided it in half. I took a spoonfull of powder and washed it down with water every 5 or 10 minute till my half was gone. I heard that it can give a similar effect as a low dose of mushrooms. Well guess what. Nothing happened till about 4 in the morning. I woke up and had projectile vomit in my bathroom. I puked every 10 minutes for 3 hours. Calamus has a chemical in it that helps you produce bile, so I was pretty much puking up pure bile. That was the most bitter thing in the world I have ever tasted. Its like taking 10 pain killers and chewing them and getting every last bit of flavour. The taste of the bile made me puke even more."
Violent vomiting and not much else. Don't sound very nice, right? Another user bought a bunch of sweet flag and had a slightly different experience:
"I noticed enhanced vision with very possible pupil dilation. I also noticed my normally high latent anxiety levels disappeared. As of yet I have not noticed any sort of stimulant effects, but the other effects are quite pleasant. The stuff tastes terrible, but chewing a bunch of gum along with it effectively negates this."
Not mind-blowing, then, and the stuff (which, as an aside, smells really good and is even used in perfume) tastes terrible, but it may just do something. Scientific studies have confirmed that Acorus calamus can be hallucinogenic , as well as that people performing internet searches for things such as "buy herbal high" and "buy legal high" have bought sweet flag . Another study that acknowledged that some people do try to use sweet flag as a recreational drug found — in agreement with one of the quotes above — that prolonged vomiting that could even last for more than 15 hours seemed to be Acorus camalus' most obvious effect .
In conclusion, if you're a healthcare provider, you may want to be aware that some people seek to use sweet flag as a street drug. If you're a casual drug user, you know that no illicit drug has been deemed completely safe for use, and that even legal "drugs" like booze and cigarettes can kill. Sweet flag is no exception, and though many more studies ought to be done to determine just how dangerous it may be, all we can do, in good faith, is recommend that you stay well away from it.
Do You Have To Worry About Hallucinations If You Are Using Sweet Flag (Acorus Calamus) As A Traditional Medicine?
Acorus calamus has been, and is still, used in disciplines of traditional medicine across the world. The more well-known of these in the Western world are Traditional Chinese Medicine and Ayurveda . If you do end up using it for one of the many purposes it is deemed to be helpful for, such as bronchitis, cognitive function, diarrhea, arthritis, and epilepsy, we suggest you do so under the watchful eye of a qualified practitioner of one of those branches of alternative medicine. When doing so, you will want to take the fact that sweet flag's active component, beta-asarone, has been found to be carcinogenic in large quantities into account — and ask yourself if there's a safer alternative before you turn to Acorus calamus.