Though Gesneriaceae do not contain significant and widely used medicinal plants, a number of species have been (or still are) widely used by the indigenous people of tropical America and Asia. The first detailed studies of gesneriad ethnobotany were carried out by Kvist (1986) and Kvist & Holm-Nielsen (1987) in Ecuador. A survey on medicinally used neotropical gesneriads was given by Wiehler (1995). Uses are extremely manifold, and no principal or predominant use of Gesneriaceae can be quoted.
Here a few examples from the larger genera (Species, Use, Country):
Aeschynanthus parviflorus, Fertility promotion, Nepal
Besleria calantha, Against snakebites, Ecuador
Columnea sulfurea, Against diarrhea, Belize
Codonanthe crassifolia, For curing colds and cough, Central America
Cyrtandra pendula, Against fever, after childbirth, Malaysia
Didymocarpus aromaticus, Aromatic tea, North India, Nepal
Drymonia serrulata, Curing skin eczema, Ecuador
Kohleria hirsuta, Remedy for kidney afflictions, Colombia, Venezuela
Loxostigma griffithii, To cure venereal diseases, China
Sinniniga tubiflora, Purgative, Argentina