culén

What is culén?

Culén is an Andean shrub whose dried leaves are brewed as a digestive tea. People drink it mainly for an upset stomach, gas and loose stools. Its botanical name is Otholobium glandulosum; older books list it as Psoralea glandulosa.

The plant grows wild in Chile, Peru, Bolivia and Argentina. In Chile it is also called té de Chile or albaquillo. The crushed leaves smell of lemon and resin.

Here is the honest verdict. Culén has a long, well recorded place in South American home medicine. It has almost no testing in people, so its effects remain unproven.

Long use is not proof that a plant works. It is also not proof that a plant is safe. Both points matter here, because culén contains furanocoumarins, natural compounds that can make skin burn in sunlight.

You will usually meet it as loose dried leaf sold in markets or online. It is not a regulated medicine anywhere. What is in a bag can vary a lot from one seller to the next.

How does culén work?

No one has shown how culén acts in the human body. What follows comes from laboratory dishes and animal work, not from patients.

The leaves are rich in bakuchiol. In cell and test tube studies, bakuchiol slows the growth of some bacteria and damps down markers of inflammation (swelling and irritation). Whether a cup of tea does anything like that is not known.

In rodents, extracts of the plant have lowered blood sugar and protected the stomach lining from damage. These are animal findings only. They have not been repeated in people.

In test tubes, furanocoumarins such as angelicin block CYP3A4. That is a liver enzyme that breaks down many prescription drugs, and the same one grapefruit juice affects. This raises a real worry about drug levels, but the size of the effect in people is unmeasured.

Furanocoumarins also react with ultraviolet light. That reaction is well understood in chemistry and explains why skin can blister after sun exposure. It is the one mechanism here with clear human consequences.

What forms does culén come in?

Dried leaf for tea is by far the most common form. It is sold loose in Chilean and Peruvian markets and by online herb sellers.

Other forms you may see:

- Teabags blended with other digestive herbs - Alcohol tinctures (liquid extracts) - Occasional capsules of dried leaf powder - Home-made washes used on the skin

Bakuchiol also appears in skin creams. That cosmetic ingredient is usually taken from a different plant, Psoralea corylifolia, not from culén.

Where it comes from:

Culén was one of the best known home remedies of colonial Chile. Spanish chroniclers wrote about it in the sixteenth and seventeenth centuries. They praised the leaf tea as a stomach remedy and a wound wash.

Mapuche and Andean healers used the leaves for stomach pain, diarrhoea and parasites. A cup after a heavy meal was a common habit. The same tea was later given for what people called "too much sugar".

The plant also had non-medical roles. Branches were used as brooms and the wood as fuel. The name culén comes from Mapudungun, the Mapuche language.

These accounts describe what people did. They do not show that the treatments worked, and they say nothing about long term safety.

What does culén help with?

• Indigestion and stomach upset: This is the main traditional use and the most common reason people drink it today. The tea was taken after meals for fullness, gas and a sour stomach. There are no human trials for this use. A warm, aromatic drink can itself feel settling, which makes any effect hard to credit to the plant. So the honest position is unproven. If your indigestion is new, severe or frequent, it needs a proper look by a doctor.
• Diarrhoea: Tradition treated culén as a remedy for loose stools and "bad water". The leaves contain tannins, which bind proteins and have a drying, astringent taste. That chemistry is real, but no trial has tested culén tea against diarrhoea in people. Many astringent plants have failed when properly studied. Diarrhoea in a baby, an older adult, or lasting more than two days needs medical care, not tea.
• Intestinal gas and cramping: Culén was drunk for griping pains and wind, often alongside mint or boldo. The essential oil gives it a strong aromatic character, like many carminative (gas-easing) herbs. No human study has measured this. Animal work hints at effects on gut muscle, but animal gut and human gut do not always match. Treat it as a traditional habit with no proof behind it.
• Minor wounds and skin sores (as a wash): Healers applied cooled leaf water to cuts, sores and infected skin. In laboratory tests, bakuchiol slows the growth of several bacteria, including some linked to skin infection. Whether that happens on living skin has not been shown. There is a specific risk here too. Furanocoumarins left on skin can cause burns and blisters once sunlight hits them. For that reason, skin use is the least sensible way to try this plant.
• High blood sugar: A newer folk use treats culén tea as a help for diabetes. Rodent studies have reported lower blood sugar after plant extracts were given. No trial has tested this in humans. Animal blood sugar results very often fail to repeat in people. Do not treat culén as a substitute for diabetes medicine. If you take insulin or tablets, adding it without telling your doctor is risky.

What are the side effects of culén?

• Skin rash, redness or blistering after sun exposure
• Nausea or stomach upset
• Loose stools
• Darkened skin patches after sunlight
• Allergic reaction, such as itching or swelling
• Possible liver strain with heavy or long use

Good to know:

Everyday use of the tea is usually reported as well tolerated, but reporting is poor and no safety study exists.

The sunlight reaction is the side effect to respect. Furanocoumarins plus ultraviolet light can cause real burns and lasting dark patches on skin.

Liver injury has been reported with related Psoralea plants, not with culén itself. The risk for culén is unmeasured rather than proven, which is not the same as absent.

How much culén should you take?

• Recommended daily: No safe or effective dose has been set for culén, because no human trial has tested one. Labels, where they exist at all, usually describe a traditional infusion: a small amount of dried leaf steeped in a cup of hot water, once or twice a day. That figure comes from custom, not from research. This page gives no personal amount. The furanocoumarin content varies by batch, so the same spoonful can differ in strength from bag to bag.
• Best time of day: Time of day has no tested effect. Custom favoured a cup after meals, when stomach complaints usually appear. One practical point does matter. Because the plant can make skin react to sunlight, strong sun exposure soon after taking it is best avoided.
• With or without food: It is usually taken after food, in line with tradition and its use for indigestion. There is no evidence that food changes how it works. If plain tea makes you queasy, having it with a meal is reasonable.
• Time to effect: If a settling effect happens, people describe it within an hour of drinking the tea. That may be the warm drink rather than the plant. For blood sugar or skin claims, there is no reliable timeline, because there is no human evidence. It is entirely possible that culén does nothing measurable for you.
• How long to take it: Traditionally it was drunk briefly, during a bout of stomach trouble, rather than every day for months. No study has looked at long term use. Related Psoralea species have been linked to liver injury with extended use, so open-ended daily drinking is not a safe assumption. If you are using any herb daily for more than a couple of weeks, that is worth raising with your doctor or pharmacist.