Gambier extracts are brown‑ish powders obtained by boiling the leaves of *Uncaria gambir* and then evaporating the aqueous solution to yield a dried, water‑soluble concentrate. The product is typically refined to remove insoluble fibers before being packaged for trade.

Because the material is hygroscopic, it should be sealed in moisture‑proof bags and loaded in dry containers; a certificate of origin and a phytosanitary clearance are routinely required by most importing countries, and shipments are often scheduled during the post‑monsoon harvest period to ensure consistent quality.