Due to its extremely localised distribution, N. dubia is listed as Critically Endangered on the 2006 IUCN Red List of Threatened Species. N. dubia occurs at several locations along the only permanent trail up Mount Talakmau. However, the upper pitchers of this species bear a peristome, and so are not as desirable as those of N. inermis. Because of this, wild populations of N. dubia have not suffered from over-collection.