Bilobalide is a sesquiterpene lactone constituent found in Ginkgo biloba leaves. Research has shown that bilobalide may have neuroprotective effects, including the modulation of neurotransmitter systems such as acetylcholine. Several animal and in vitro studies suggest that bilobalide can inhibit acetylcholinesterase, the enzyme responsible for breaking down acetylcholine, potentially increasing acetylcholine levels in the brain. This mechanism is relevant because acetylcholine is a critical neurotransmitter for memory and cognitive function, and its deficiency is associated with neurodegenerative conditions such as Alzheimer’s disease.

However, most of the clinical evidence supporting bilobalide’s effect on the cholinergic system comes from studies on Ginkgo biloba extracts as a whole, rather than on isolated bilobalide. While bilobalide is considered one of the active components, direct human clinical trials focusing solely on bilobalide’s impact on acetylcholine or cognitive outcomes are limited. Thus, while there is a plausible scientific rationale and some preclinical support, robust clinical evidence is lacking, and therefore the overall evidence level is moderate to low. The use of bilobalide to support the acetylcholine system is scientifically plausible but not conclusively validated in humans.