What is jambú?

Jambú is a low, leafy herb from the Amazon, known in English as paracress or the toothache plant. Its botanical name is Acmella oleracea. Cooks and healers use the leaves and the small yellow-and-red flower buds.

Chewing it makes the mouth fizz, tingle and go numb for a few minutes. In the Brazilian state of Pará it is an everyday vegetable, used in dishes such as tacacá and pato no tucupi. Elsewhere it is sold as an extract for mouth gels, toothpaste and skin creams.

Here is the honest verdict. Human evidence is thin and mostly short and small. A few trials suggest mouth gels can dull pain for a short time, and long traditional use is not proof that it works or that it is safe.

How does jambú work?

The buzzing comes from spilanthol, an oily compound packed into the flower buds.

In laboratory tests, spilanthol acts on nerve endings and dampens pain signals. That fits the brief numbness people feel when they chew it. How deep that numbing goes, and how long it lasts, is not well mapped in people.

Cell and animal studies also report less swelling and some relaxing of tiny muscles under the skin. Cosmetic makers use this to claim softer wrinkle lines. Those claims rest on lab work and small company studies, not on strong human trials.

Lab and animal work suggests the plant can make you produce more saliva. A couple of small human studies point the same way. Treat that as an early signal, not a settled effect.

What forms does jambú come in?

Fresh leaves and flower buds are the traditional form, cooked into soups, broths and stews.

You may also meet it as:

- dried leaf or powder - tinctures and alcohol infusions, including cachaça drinks - mouth rinses, numbing dental gels and toothpaste - lip plumping balms and anti-wrinkle creams or serums - capsules of extract sold as a supplement

Strength differs hugely across these. A pinch of leaf in a shared pot is not the same as a concentrated extract. Essential oil and strong extracts are the forms to treat with most care.

Where it comes from:

Indigenous and caboclo communities of the Brazilian Amazon used jambú as both food and medicine for generations.

The bruised leaf or bud was held against a sore tooth or gum for numbing, which gave the plant its English name. Healers also used it for mouth sores, sore throat, poor appetite and sluggish digestion. Some accounts list it as a tonic or aphrodisiac.

Related Acmella species were used in similar ways in parts of Africa and South Asia. The plant later travelled into bars and restaurants worldwide as a novelty tingle. None of this history was a test of safety or of benefit.

What does jambú help with?

• Toothache and short-term mouth pain: This is the oldest use and the one with the most support. Chewed bud or leaf numbs the area within a minute or two. The relief is brief and shallow. It does nothing about the cause, which is usually decay or infection. A tooth that hurts needs a dentist, not a herb.
• Numbing before a dental injection: Small trials have tested Acmella gels on the gum before a needle goes in. Some reported slightly less pain than a dummy gel; others found no clear difference. The studies were small and short. Nothing here replaces a dentist's own numbing injection.
• Dry mouth and low saliva: Tradition used jambú to get the mouth watering. Lab and animal work supports a saliva-boosting effect, and a few small human studies agree. This is early evidence. Whether it helps people with long-term dry mouth from illness or medicines has not been shown.
• Mouth ulcers and sore gums: Rinses and gels were used to take the edge off sore spots. In test tubes, extracts slow some mouth bacteria and calm markers of swelling. Whether that happens on real gums is not established. Human trials are few and small.
• Sore throat: Folk use included gargles and infusions for a raw throat. There is no good human trial for this. Any benefit is likely the numbing and the extra saliva. A sore throat with fever, rash or trouble swallowing needs medical review.
• Poor appetite and slow digestion: Jambú was eaten as a food that wakes up the mouth and the appetite. Bitter, tingling plants are used this way across many traditions. Human evidence is essentially absent. Treat this as a food habit, not a treatment.
• Cosmetic use for fine lines: Extracts are sold in creams marketed as a gentler stand-in for wrinkle injections. The idea comes from lab reports that spilanthol relaxes small muscle and skin fibres. Most supporting studies are small and run by ingredient makers. Independent human evidence is weak, and the effect, if any, is short-lived.

Which foods are rich in jambú?

Jambú is a food plant, not a nutrient found in other foods. In northern Brazil it appears in tacacá, in tucupi broth with duck, and in rice and sautéed greens.

Cooking softens the tingle but does not remove it. Eating it as part of a meal is the lowest-risk way it is used.

What are the side effects of jambú?

• Strong tingling, fizzing or burning in the mouth
• Numb tongue, lips and cheeks
• A rush of saliva or drooling
• Changed or dulled taste
• Biting your tongue or cheek while numb
• Nausea or stomach upset after large amounts
• Throat irritation
• Redness, itching or rash from creams and balms
• Allergic reaction in people sensitive to daisy-family plants

Good to know:

The tingling and numbing are expected, not a warning sign. They are the reason people use the plant.

At food amounts, serious problems appear to be rare. Most reports involve mild mouth or stomach upset.

Concentrated extracts, essential oil and strong tinctures carry more risk, and they have barely been studied in people. Allergy is possible, especially if ragweed or chamomile bothers you.

How much jambú should you take?

• Recommended daily: There is no established dose, because the human studies are too few to set one. In Pará cooking, a small handful of leaves and buds flavours a pot shared by several people. Cosmetic creams carry the extract at a low percentage of the finished product. Dental gels and rinses are used in a thin layer on one spot. This page gives no personal amount. Capsules and tinctures vary widely in strength, and labels rarely say how much spilanthol they hold.
• Best time of day: Timing does not matter much. As a food, it is eaten with meals. For mouth numbing, people use it when the pain is there.
• With or without food: Jambú is itself a food and is normally eaten cooked, in a dish. Extracts and capsules are usually taken with food, which may reduce stomach upset.
• Time to effect: The tingle starts in seconds and numbing follows within a minute or two. It usually fades within about 10 to 20 minutes. Skin cream claims are a different matter. Makers talk about weeks of use. It may also do nothing you can notice.
• How long to take it: Traditional and modern use is short and local. The numbing lasts minutes, so people reapply rather than take it daily. There is no safety data on taking concentrated extracts for weeks or months. If you are using it for pain that keeps coming back, the problem needs a diagnosis.