Search for chilcuague and you will quickly meet the phrase "Mexican toothache plant". The naming is worth untangling, because two different plants are routinely confused.
Two plants, one compound
The toothache plant proper is Acmella oleracea, also sold as jambu or paracress, and native to South America. Its leaves and flowers are the parts used.
Chilcuague is Heliopsis longipes, a different species, endemic to the Sierra Gorda and Sierra Álvarez in central Mexico. Its root is the part used; the alkamides are found there and not in the aerial parts.
What links them is chemistry. Both contain the same alkamide, called spilanthol in the Acmella literature and affinin in work on Heliopsis longipes. Because that shared compound produces the same tingling, saliva-inducing effect in both plants, the "toothache plant" label has drifted across to chilcuague. Hence "Mexican toothache plant".
Why the distinction matters
If you are buying, species and plant part both matter. A product made from Acmella leaf is not chilcuague, even where the sensory effect overlaps. Tonalli uses Heliopsis longipes root, sourced from Guanajuato.
A note on the name
The common name reflects historical folk usage, not a claim about our product. Tonalli Chilcuague is a botanical product, not a therapeutic good, and is not intended to treat, cure or relieve toothache or any other condition. For dental pain, see a dentist.