What is Luo Han Guo?

Luo Han Guo is the dried fruit of a vine that grows in southern China. It is also called Momordica Fruit, or monk fruit. It is a single drug (TCM herb), which means it is used on its own and not as part of a fixed blend.

People drink it as a sweet tea for a dry cough, a dry or sore throat, and hard, dry stools. The fruit tastes very sweet but holds almost no sugar and few calories. For that reason it is also sold as a sweetener for drinks and food.

Here is the short verdict. Luo Han Guo has a long record of use in Chinese medicine, but human trials on the herb itself are few and small. A long history of use is not proof that something works, and we say that here once rather than in every section.

How does Luo Han Guo work?

The sweet taste comes from mogrosides. These are sweet compounds in the fruit that are far sweeter than sugar, but the body takes in very little of them.

In Chinese medicine the fruit is seen as sweet and cool. It is said to cool heat in the lungs, moisten a dry throat and soften dry stools. This is a traditional way of describing the body, not a lab finding.

Lab and animal studies suggest the fruit may calm swelling and mop up some cell damage. What that means for a person drinking the tea is still unclear.

What forms does Luo Han Guo come in?

You can buy it in several forms: - Whole dried fruit, broken open and simmered or steeped to make tea - Cut and sifted pieces or slices for tea - Powdered fruit extract, sold as a sweetener - Liquid drops and syrups for drinks - Sachets and cough teas that blend it with other herbs Sweetener products are often mixed with erythritol (a sugar alcohol used for bulk), so check the label.

Where it comes from:

The fruit has been grown in Guangxi in southern China for hundreds of years. Local records tie its name to monks who farmed it, which is where the name monk fruit comes from.

It entered Chinese herbal practice for dry cough, hoarse voice and dry stools. It is a well known staple of that one tradition rather than a herb shared across many. In modern times it has spread worldwide mainly as a sugar substitute.

What does Luo Han Guo help with?

• Dry cough: This is the classic traditional use. The warm sweet tea coats the throat and may ease the tickle that keeps a dry cough going. We could not find a published human trial testing the herb for cough, so treat this as tradition and comfort, not proof.
• Sore or dry throat and hoarse voice: Singers and teachers in China have long sipped it for a tired voice. Any warm sweet drink can soothe a throat, so it is hard to tell the herb apart from that effect. No trial has separated the two.
• Constipation with hard, dry stools: Chinese medicine uses it to moisten the bowel, and it is seen as gentle rather than strong. There is no human trial showing it relieves constipation. If stools stay hard for weeks, get checked instead of waiting.
• Thirst and dry mouth: Traditionally it was given for thirst and a dry mouth, including in people who feel constant thirst. This is traditional use only. Constant thirst can be a sign of diabetes and needs a doctor, not a tea.
• Sugar-free sweetening for people cutting sugar: This is the best supported use. Monk fruit sweetener adds sweetness with almost no calories and does not appear to raise blood sugar in the way table sugar does. Swapping sugar for it may help with calorie intake, but it is not a treatment for diabetes or weight loss.

Which foods are rich in Luo Han Guo?

1. Monk fruit sweetener: the fruit extract itself, sold as powder, drops or granules
2. Sugar-free drinks and sodas: often sweetened with monk fruit extract
3. Sugar-free chocolate, protein bars and yoghurts: monk fruit is a common sweetener
4. Chinese herbal cough teas and cooling drinks: often list Luo Han Guo on the label

Practical Tips:

No ordinary food holds the fruit naturally; it appears as an added sweetener or as tea.

What are the side effects of Luo Han Guo?

• Loose stools or mild diarrhoea, mostly with strong tea or large amounts
• Gas and bloating, often from the erythritol (a sugar alcohol) mixed into sweetener blends
• Nausea from the very sweet taste
• Rash, itching or swelling in people allergic to gourd-family plants
• A faint bitter or fruity aftertaste that some people dislike

Good to know:

Side effects are uncommon and usually mild. Luo Han Guo has been eaten as a food in China for a long time, and monk fruit sweetener has been reviewed and allowed as a food ingredient in many countries.

Most gut complaints come from the bulking agent in sweetener blends rather than the fruit itself. Allergy is rare but can be serious, so stop at the first sign of a rash or swelling.

How much Luo Han Guo should you take?

• Recommended daily: No dose has been proven in human trials. Traditional Chinese practice uses about 9 to 15 grams of the dried fruit a day, simmered in water as a tea. In home use, people break open one dried fruit and use a quarter to a half of it for a large mug or pot. As a sweetener, follow the label, since extracts are hundreds of times sweeter than sugar.
• Best time of day: Any time of day. Many people sip it in the evening, when a dry cough tends to feel worse.
• With or without food: With or without food. If the sweetness upsets your stomach, take it after a meal.
• Time to effect: The soothing feel on the throat is immediate while you drink it. Any effect on a cough, if it comes, tends to show over a few days.
• How long to take it: Short-term use is the norm. Drink it for a few days to about two weeks while a dry cough or dry throat settles. If you still need it after two weeks, stop and see a doctor to find the cause. Sweetener use is a daily food choice rather than a course of treatment.