What is Chimhyang?

Chimhyang is the resin-soaked heartwood of the agarwood tree, Aquilaria agallocha (also written Aquilaria sinensis). In English shops it is sold as agarwood or aloeswood. Korean medicine treats it as a warm, strongly aromatic herb for the stomach and the chest.

It is given mainly for cold, cramping belly pain, for nausea, vomiting and hiccups, for wheezing and tight breathing, and as a calming scent. It is almost always used in a small amount inside a multi-herb formula rather than on its own.

The evidence grade here is insufficient: we could not find human trials of Chimhyang for any of these uses. Its standing comes from centuries of recorded use across several Asian medical systems, and long use is not proof that something works.

How does Chimhyang work?

Nobody has shown in people how Chimhyang works, so what follows is a description of ideas, not proven action.

In Korean medicine the wood is said to be warm and sinking. Practitioners use it to "move qi" downward, meaning to settle a stomach that pushes upward with vomiting or hiccups and to ease breath that feels stuck high in the chest.

Laboratory and animal studies point to the aromatic oil. Sesquiterpenes (aromatic oil compounds) from agarwood have calmed the gut muscle of animals and made mice less active, which fits a mild sedative and antispasmodic (cramp-easing) effect. Animal results often do not carry over to people.

What forms does Chimhyang come in?

Chimhyang comes as wood chips or coarse powder for a decoction (a simmered tea), and as fine powder for pills and capsules. In Korean practice it is usually one small part of a larger formula.

It is also burned as incense and distilled into an essential oil used for scent. Graded chips sell to collectors at very high prices.

That high price makes fake and padded product common. Buy only from a Korean medicine dispensary or a licensed herb supplier who can name the species, because cheap agarwood is often plain wood soaked in synthetic fragrance.

Where it comes from:

Agarwood has been traded and used medicinally for well over a thousand years. It appears in Korean medical texts, including the Donguibogam (1613), among the warming, qi-moving aromatics.

The same wood is a named remedy in Chinese medicine (chenxiang), in Ayurveda and Unani (agaru, oud), and in Tibetan practice. It also has a long religious and perfumery life as incense, which is a separate story from its medical use.

What does Chimhyang help with?

• Cold, cramping pain in the upper belly: This is the classic Korean use: a small dose inside a warming formula for a belly that hurts, feels cold and eases with heat. Animal work shows agarwood extracts can relax gut muscle. No human trial has tested it for stomach pain.
• Nausea and vomiting: Traditional texts use Chimhyang to settle a stomach that keeps pushing upward, often with ginger and other warm herbs. There is no human trial evidence for this, and vomiting that lasts more than a day or two needs a medical opinion rather than an herb.
• Hiccups and belching: Long-standing traditional use for persistent hiccups and constant belching, again as part of a formula. The evidence stays at the level of tradition and old case records. Hiccups lasting more than 48 hours should be checked by a doctor.
• Wheezing and tight, shallow breathing: Korean and Chinese texts use it for breath that feels stuck in the chest, including in asthma-type patterns. This is traditional use only. Chimhyang is not a rescue treatment, and burning it as incense can make asthma worse rather than better.
• Restlessness and poor sleep (used as a scent): Inhaled agarwood smoke or oil is a traditional calming aroma. Mouse studies found reduced activity after inhaling the vapour. We found no human sleep trial, so treat this as a pleasant scent with an unproven effect.

Which foods are rich in Chimhyang?

1. Agarwood chip tea: chips steeped in hot water, drunk as a traditional aromatic tea rather than as food
2. Agarwood-scented incense: burned, not eaten

Practical Tips:

Chimhyang is a medicinal and aromatic wood, not a food, and it is not part of any normal diet.

What are the side effects of Chimhyang?

• Drowsiness or a heavy, dull feeling
• Dry mouth
• Nausea or stomach discomfort, especially on an empty stomach
• Headache from the strong scent or smoke
• Coughing, wheezing or eye irritation from burning incense
• Skin rash or itching in people sensitive to aromatic woods

Good to know:

Most people who take a small amount inside a formula report no problems, and serious harm has not been described in the medical literature. That is partly because agarwood has barely been studied in people, so mild or rare effects may simply be unrecorded. Stop it and ask for advice if anything new starts after you begin.

How much Chimhyang should you take?

• Recommended daily: There is no modern established dose. Traditional Korean and Chinese practice uses roughly 1 to 3 g of chips or coarse powder per day in a decoction, or about 0.5 to 1 g as a fine powder, always inside a formula. Because the resin content varies so much, a practitioner judges the dose from the material in front of them. Do not scale up on your own.
• Best time of day: Usually taken in two or three small doses through the day, timed around meals. As a scent, it is used in the evening.
• With or without food: Take it with or just after food. The aromatic resin can feel harsh on an empty stomach.
• Time to effect: Traditional use expects a settling effect within an hour or two for nausea or hiccups. This timing comes from practice, not from trials.
• How long to take it: Traditionally it is used short term, for days to a couple of weeks, while the symptom lasts. If nothing has changed in two weeks, stop and get your symptom looked at properly.