Some Medicines Are Felt the Moment You Take Them — Each Compound Travels a Different Road

"The moment I swallow it, I feel something moving."

Some people say this to me. I do not put it down to imagination. There really are medicines like that, and there is some explanation for why.

By the theory, it ought to take time

A good share of the compounds in herbal medicine are glycosides — an active substance with a sugar attached. In that state they are weak and poorly absorbed. They have to travel down to the large bowel, where gut bacteria strip that sugar off, before they become something usable. (The same remedy works differently when the gut is different)

This road is slow. It has to reach the large bowel. That takes hours.

So "I feel it the moment I take it" sounds odd. It has not even arrived in the gut yet.

One herb does not hold one compound

Here I want to mention something I misunderstood for a long time.

We have a habit of sorting herbs by compound. This one is a glycoside herb, that one a volatile-oil herb, and so on. It does not work that way.

A single herb holds tens, hundreds of compounds. Within one herb there are glycosides, and volatile oils, and lipid components. Depending on the herb there may be alkaloids as well. There is no herb that holds only one thing.

So the question changes. Not "which road does this herb take," but "which compound inside this herb takes which road, and when."

Some compounds have no need to reach the large bowel

Our cells are wrapped in an oily membrane, made of phospholipid. Things that dissolve in water have a hard time crossing it; things that dissolve in oil pass fairly easily.

So a compound that is strongly oil-side and small in molecule simply passes through this membrane. It has no need to go down to the large bowel and meet bacteria. The volatile oils are the obvious example.

What matters is not the compound's label but its character. Even a compound carrying two or more characters at once will cross the membrane quickly if the oil side weighs more and the molecule is small. Compounds grouped in the same family part ways on this condition. Not what it is, but which characters it has and how much of them, decides the road.

Volatile oils do not only pass through

There is one more reason the volatile oils are fast. Their power to stimulate nerves is large.

The olfactory receptors inside the nose respond, and sensory nerve receptors around the body respond too. Before it has crossed a membrane and arrived anywhere, a signal has already gone. So herbs rich in volatile oils give a fast response.

That the medicines used for the nerves, the medicines that respond quickly, are rich in volatile oils is not a coincidence.

There is something here I still do not know. How much of what the volatile oils do comes from fitting a particular receptor like a key — that I am not clear on myself. I can tell you as far as crossing the membrane and touching nerves; past that, I have not been able to confirm.

That said, "rich in volatile oils" does not mean "a fast medicine"

Here I want to be clear about one thing. Reading this far, a rule seems ready to form — rich in volatile oils = works fast = the medicine for when you are in a hurry.

It does not work that way.

There is an herb called Asarum (seshin). It is very strong in volatile oils. And yet I use this one for long-standing problems. Not the place for putting out a sudden fire, but the place that has dragged on. Depending on the case I sometimes set a long course. (Though Asarum is an herb whose dose and duration have to be decided with particular care, which is why it is not one to judge on your own.)

Having the fast road does not mean it only does fast work. How quickly the road opens and what job the medicine takes on in the body are two different stories.

So to put it exactly: which road a compound takes is decided by that compound's character, and where the herb gets used is another matter. Tying the two into one is convenient, and wrong in proportion to the convenience.

So the same herb holds several time frames

Licorice and Poria are the sort of herbs I often hear the "I feel it right away" remark about.

Take licorice as the example. Licorice's best-known compound is glycyrrhizin — the one that gives the sweetness, and it comes with a sugar attached. Measured against human gut cells, this form barely crosses at all. It has to go down to the large bowel and have bacteria take the sugar off before it enters the body. The slow road.

Yet within that same licorice, the forms with the sugar already off cross straight through in the small intestine. They parted that way in the same experiment. And licorice root holds volatile oils as well.

So one dose of licorice does not have a single time frame.

• The moment you swallow — the volatile oils touch the nose, the mouth, the sensory nerves
• Passing through the small intestine — the compounds with the sugar off cross the membrane
• Some hours later — the share the bacteria in the large bowel have unlocked comes in late

One herb, and three arrival times. And what comes first changes the conditions for what comes later. (Herbal medicine has side effects too — the licorice story)

This is why I do not draw herbal medicine's action as a single line. The doors are several, the timing is staggered, and they touch one another. (What herbal medicine does)

I ask when you first felt it

I ask, "when did you start to feel it?" Right after taking it, some hours later, some days later — this answer lets me guess which road opened.

I do not read a fast response as the size of the effect. Feeling it quickly does not make it a medicine that works well, and taking a few days does not make it weak. A different road opened, that is all.

And the way it is decocted hangs on this. Volatile oils fly off with heat. Boil long and hard, and the fast share is reduced. Which share you want to keep changes how you decoct.

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Saying you feel it the moment you take it is not imagination. It is because one herb holds several compounds, and each compound has its own road and its own time of arrival.

And knowing the road does not mean you also know what that medicine will do. There are herbs like Asarum that hold the fast road and get used in the place that takes a long time.

This is where the reason lies that herbal medicine cannot be explained by one line of a compound list.

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References

• Ten licorice compounds measured against human gut cells — the ones with sugar attached barely crossed, the ones with the sugar off crossed well — Molecules, 2017
• Which compounds sit together in the single herb licorice, and why glycyrrhizin has to pass through the hands of the gut microbes — Phytotherapy Research, 2018
• A review setting out how volatile oils work differently in the body according to the route by which they enter — including the olfactory receptors and the sensory nerves — International Journal of Molecular Sciences, 2020

Written by Dr. Heo Ji-young (PhD in Korean Medicine Pathology, Kyung Hee University · former Research Professor of Herbology, Kyung Hee University)