Terpene lactones are a class of compounds found most notably in Ginkgo biloba extracts, which have been traditionally used in herbal medicine for various circulatory and neurological conditions, including tinnitus. The use of Ginkgo biloba for tinnitus is based more on historical and traditional practices rather than robust scientific evidence. In traditional medicine, it is believed that Ginkgo improves blood flow to the inner ear and brain, potentially alleviating symptoms of tinnitus by addressing circulatory deficiencies.

Scientific studies evaluating the efficacy of Ginkgo biloba extract (which contains terpene lactones such as ginkgolides and bilobalide) for tinnitus have produced mixed and generally inconclusive results. Systematic reviews and meta-analyses, including those by Cochrane, have found little consistent evidence to support its effectiveness over placebo for tinnitus management. While some small studies have suggested minor improvements in tinnitus symptoms, the overall quality of the evidence is low, with methodological flaws and heterogeneity in study designs and outcomes.

In summary, the rationale for using terpene lactones (via Ginkgo biloba extracts) for tinnitus is primarily rooted in tradition, and scientific support is weak. Most clinical guidelines do not recommend Ginkgo or terpene lactones as a standard treatment for tinnitus due to insufficient high-quality evidence.