Spilanthes / Toothache Plant (Acmella oleracea): Spilanthol, Traditional Use, Research & Safety

Spilanthes, better known today botanically as Acmella oleracea, is the famous toothache plant, jambu or paracress. Bite into a flower head and the effect is immediate: tingling, buzzing, numbness and a rush of saliva. That striking sensory response is largely associated with spilanthol, a lipophilic N-alkylamide found in the flowers and other parts of the plant.

The plant has a long culinary and medicinal history, especially in Brazil and other tropical regions, and older herbal literature commonly lists it under the former name Spilanthes acmella. Modern pharmacology supports real anesthetic, antinociceptive, anti-inflammatory and salivation-promoting effects in experimental systems. Human clinical evidence, however, is much thinner than the laboratory literature. Toothache plant deserves respect as a distinctive medicinal food plant without pretending it replaces treatment for a cracked tooth, abscess or dental infection.

Botanical Identity

Accepted botanical name: Acmella oleracea (L.) R.K.Jansen
Family: Asteraceae
Older name commonly found in herbal literature: Spilanthes acmella
Common names: toothache plant, jambu, paracress, electric daisy, buzz button, eyeball plant

Royal Botanic Gardens, Kew accepts Acmella oleracea as the current species name and describes it as a cultivated lineage originating from southeastern Brazil. It has since been introduced widely through tropical and subtropical regions and is used as both food and medicine.

Why the Name “Spilanthes” Still Appears

The herbal trade, older pharmacology papers and many gardening references still use Spilanthes acmella. Modern taxonomy places the plant in the genus Acmella. When reading research, check whether the paper’s plant material is actually the same accepted species rather than assuming every plant called “spilanthes” is identical.

Identification

Acmella oleracea is a warm-season annual in temperate gardens and may behave more persistently in tropical climates. It has opposite, broadly ovate to triangular leaves with toothed margins and low, branching stems that may be upright or somewhat sprawling.

The flower heads are the unmistakable feature. They are rounded to elongated cones, usually yellow to golden, sometimes with a reddish-brown or orange center depending on cultivar. Unlike a typical daisy, they may have no showy outer ray petals, giving the heads their “eyeball” or button-like appearance.

Culinary Use: Jambu

In northern Brazil, especially Pará and the Amazon region, jambu is a well-known culinary herb. Leaves and flowers are used in regional foods, including dishes associated with tacacá and other traditional preparations.

The tingling and mouth-watering sensation is not a sign of spoilage—it is the defining sensory quality of the herb. Modern chefs have also adopted flower heads as “buzz buttons” in cocktails and novelty dishes.

Food use does not mean unlimited concentrated-extract use is automatically safe. Eating a few leaves or flowers is a different exposure from taking purified spilanthol or a strong tincture.

Spilanthol: The Signature Compound

Spilanthol is the most studied constituent of toothache plant. It belongs to a group of compounds called N-alkylamides or alkamides. Spilanthol is lipophilic, penetrates biological membranes readily and appears capable of interacting with sensory and pain-signaling pathways.

Reviews describe effects that include:

  • tingling and numbing sensation;
  • strong stimulation of salivation;
  • local anesthetic activity;
  • antinociceptive and analgesic effects in experimental systems;
  • anti-inflammatory activity;
  • antimicrobial and insecticidal effects in laboratory studies.

The plant also contains other alkylamides, phenolic compounds, flavonoids, triterpenoids and volatile constituents. Spilanthol is important, but it is not the entire chemistry of the herb.

The Toothache Tradition

Toothache plant has been chewed or applied locally in traditional medicine to numb aching gums and teeth. The intense salivation it causes may also have contributed to its reputation in oral and throat complaints.

The traditional use makes pharmacologic sense because spilanthol and related compounds have demonstrated anesthetic and pain-modulating activity. But there is an important boundary:

Numbing pain is not the same as fixing the cause of dental pain. Cavities, abscesses, cracked teeth, periodontal infection and exposed nerves can worsen even if pain temporarily decreases.

Modern Pain Research

A modern review dedicated to Acmella oleracea and pain management found a substantial experimental literature supporting analgesic, anti-inflammatory and antinociceptive effects. Proposed mechanisms include effects on voltage-gated sodium channels and signaling systems involving prostaglandins, serotonin, GABA and opioid pathways.

Much of this evidence comes from cell, isolated-tissue or animal work. There is not yet a large body of well-controlled human trials demonstrating that a particular dose of whole-plant Acmella oleracea reliably treats dental, neuropathic or musculoskeletal pain.

Salivation and Dry Mouth Interest

The strong sialagogue effect—stimulation of saliva—is one of the most reproducible human sensory effects of the plant. That has created interest in spilanthol-containing products for dry mouth and oral-care formulations.

Saliva supports oral lubrication, swallowing, taste, buffering and enamel protection. However, persistent dry mouth can result from medications, Sjögren disease, radiation treatment, diabetes or other causes and deserves evaluation rather than being treated only with a salivary stimulant.

Antimicrobial and Oral-Care Research

Extracts and isolated constituents have shown antibacterial and antifungal activity in laboratory studies, including activity against some organisms relevant to oral health. These findings help explain the plant’s historical oral-care reputation.

Laboratory inhibition does not establish that chewing a flower treats an abscess or eradicates periodontal infection. An infected tooth can spread infection beyond the mouth and should not be managed solely with an antimicrobial herb.

Anti-Inflammatory Research

Modern studies report effects on inflammatory signaling pathways including NF-kB-related processes and inflammatory mediators such as COX-2, nitric-oxide pathways and cytokines. These effects are primarily preclinical.

It is reasonable to say that the plant has experimentally demonstrated anti-inflammatory activity. It is not yet reasonable to market it as a clinically proven treatment for arthritis, inflammatory bowel disease or other chronic inflammatory diseases.

Other Experimental Claims

The scientific literature has explored Acmella oleracea for a long list of possible effects, including antioxidant, vasorelaxant, diuretic, antidiabetic, insecticidal, antifungal and immunomodulatory activity. Older reviews also discuss traditional aphrodisiac use.

Most of those claims remain based on animal, laboratory or traditional evidence. The existence of a pharmacology paper is not the same as established human effectiveness.

Cancer Research

Spilanthol and related plant constituents have been investigated for effects on cultured cancer cells and drug-delivery systems. These studies are experimental and should not be turned into claims that jambu or toothache plant treats cancer in people.

Safety

Culinary use of jambu has a long history, but formal safety data for concentrated extracts remain incomplete.

  • Oral sensation: tingling, numbness and heavy salivation are expected effects rather than an allergy by themselves.
  • Swallowing: intense oral numbness could theoretically make swallowing feel unusual; avoid excessive amounts when eating or drinking quickly.
  • Asteraceae allergy: people allergic to members of the daisy family may be more likely to react and should use caution.
  • Pregnancy and breastfeeding: reliable human safety data for concentrated medicinal extracts are inadequate.
  • Children: strong tinctures or concentrated extracts have not been well studied in children.
  • Medication interactions: human interaction research is sparse. The plant’s experimental effects on vascular, inflammatory and metabolic pathways mean concentrated use should not automatically be assumed interaction-free.

Can It Be Put Directly on a Tooth?

Traditional use often involves chewing a flower head or holding plant material in the mouth. That can create temporary numbing. It should not be packed into an open wound, deep cavity or surgical site where plant debris could remain trapped.

If there is facial swelling, fever, drainage, trauma, a broken tooth or severe pain that persists, the plant’s numbing effect can mask a problem without resolving it.

Growing Toothache Plant

Acmella oleracea likes warmth, sun and consistent moisture. In temperate climates it is generally grown as an annual after frost danger passes. It can be started from seed indoors or direct-sown once soil is warm.

Plants branch readily and produce numerous flower heads when harvested regularly. Pinching young plants encourages bushier growth. Hot weather is usually welcomed, but severe drought can reduce tender leaf production.

Harvesting

Leaves and flower heads are both used. Flowers generally produce the strongest “electric” mouth sensation and are often harvested when fully formed but still fresh.

For culinary use, harvest healthy material and wash it like any other fresh herb. For tincture or research-oriented material, note which plant part is being used because spilanthol concentration can vary between flowers, leaves and stems and with harvest stage.

Drying and Storage

Flower heads can be dried with good airflow away from excessive heat and direct sun. Store completely dry material in airtight containers away from light. The sensory potency of dried material may gradually decline as volatile and labile constituents age.

Sourcing

Because the old botanical name remains common in commerce, a legitimate label may say either:

  • Acmella oleracea, or
  • the older Spilanthes acmella.

For serious research comparison, confirm that the supplier’s plant is the accepted species and identify the plant part. “Spilanthes” can be used loosely in the trade.

Bottom Line

Toothache plant is not a myth. Its flowers genuinely create a strong numbing, tingling and saliva-producing effect, and modern pharmacology provides plausible mechanisms for its long reputation as an oral pain herb. Spilanthol is a biologically active alkylamide with anesthetic and antinociceptive properties in experimental research.

What the evidence does not show is that toothache plant cures the cause of tooth pain or that its many laboratory effects translate into established treatments for infection, arthritis, diabetes or cancer. Its best modern description is a distinctive culinary medicinal plant with strong sensory pharmacology, promising research and still-limited human clinical evidence.

This article is for botanical and educational purposes only and is not medical advice. Temporary numbing does not replace diagnosis or treatment of a dental infection or damaged tooth.

Research & Reference Sources

Return to the Roosters Peacock Herbs & Botanicals Guide