Bilobalide

Bilobalide at a Glance

Bilobalide is a sesquiterpene trilactone found essentially only in ginkgo (Ginkgo biloba), where — with the ginkgolides — it forms the terpene-lactone fraction used to standardize the leaf extract. It is the single most abundant terpene trilactone in the standardized extract EGb 761, and one of its two marker classes alongside the flavonol glycosides ^{1,3Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 3DeFeudis FV · 2000Ginkgo biloba extract (EGb 761) and CNS functions: basic studies and clinical applicationsView study →}.

The compound-defining point is structural: bilobalide is the only sesquiterpene (C15) trilactone in ginkgo, distinct from the diterpenoid (C20) ginkgolides it sits beside. That difference tracks a difference in pharmacology. The ginkgolides — ginkgolide B in particular — are prototypical platelet-activating-factor (PAF) antagonists; bilobalide’s signature is instead antagonism of GABA-A and glycine receptors and a broad, mechanistically layered neuroprotection (mitochondrial protection, reduced excitotoxicity, anti-apoptotic and anti-inflammatory signalling) ^{4,5,10Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 5Ivic L et al. · 2003Terpene trilactones from Ginkgo biloba are antagonists of cortical glycine and GABA(A) receptorsView study →Reference 10DeFeudis FV · 2002Bilobalide and neuroprotectionView study →}.

The honest headline is the compound-page discipline: almost all bilobalide data are rodent or in-vitro studies of the isolated molecule, and the human evidence that people associate with “ginkgo” belongs to the whole EGb 761 extract, not to isolated bilobalide. There are no controlled human trials of the isolate ^{1,11Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 11Feng Z et al. · 2019ReviewThe neuroprotective mechanisms of ginkgolides and bilobalide in cerebral ischemic injury: a literature reviewView study →}.

Bilobalide vs. The Ginkgolides

Ginkgo’s “terpene lactones” are two chemically different things, and conflating them is the commonest error about bilobalide.

The ginkgolides (A, B, C, J) are C20 diterpene trilactones. Their defining action is selective PAF-receptor antagonism — the basis of ginkgo’s circulatory effects and its antiplatelet/bleeding caution — see ginkgolide B ^{3Reference 3DeFeudis FV · 2000Ginkgo biloba extract (EGb 761) and CNS functions: basic studies and clinical applicationsView study →}.

Bilobalide is a C15 sesquiterpene trilactone — the only sesquiterpene of the group. It is a poor PAF antagonist and is not the source of ginkgo’s antiplatelet signal; its own pharmacology runs through GABA-A / glycine-receptor antagonism and neuroprotection instead ^{1,4,5Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 5Ivic L et al. · 2003Terpene trilactones from Ginkgo biloba are antagonists of cortical glycine and GABA(A) receptorsView study →}. Both classes share an unusual tert-butyl group (rare in nature) and a caged, highly oxidized trilactone architecture, which is why they co-elute as the standardized “terpene lactone” fraction and why the two are so often lumped together despite doing different jobs ^{2Reference 2van Beek TA · 2005Ginkgolides and bilobalide: their physical, chromatographic and spectroscopic propertiesView study →}.

The practical framing:

• Ginkgolides — PAF antagonists (circulation, platelets).
• Bilobalide — GABA-A/glycine antagonist and neuroprotectant (CNS).
• EGb 761 — the standardized whole extract that carries the actual human evidence, in which bilobalide is one active among many.

The Anticonvulsant Paradox

Bilobalide has a genuinely paradoxical relationship with seizures that earns its own section. At the receptor it is a non-competitive antagonist of the inhibitory GABA-A receptor ^{4,5Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 5Ivic L et al. · 2003Terpene trilactones from Ginkgo biloba are antagonists of cortical glycine and GABA(A) receptorsView study →} — and blocking inhibition is normally pro-convulsant, which is why the compound carries a theoretical seizure-threshold caution at high exposure.

Yet at the tissue level bilobalide can be anti-convulsant and neuroprotective. In mouse brain it raises GABA content by increasing the activity of glutamic acid decarboxylase (GAD), the enzyme that synthesises GABA ^{7Reference 7Sasaki K et al. · 1999AnimalEffects of bilobalide on gamma-aminobutyric acid levels and glutamic acid decarboxylase in mouse brainView study →}, and it specifically prevents the fall in GABA and GAD caused by 4′-O-methylpyridoxine (ginkgotoxin) — the vitamin-B6-antagonist neurotoxin of ginkgo seeds that triggers seizures in ginkgo-nut poisoning ^{8Reference 8Sasaki K et al. · 2000AnimalBilobalide prevents reduction of gamma-aminobutyric acid levels and glutamic acid decarboxylase activity induced by 4-O-methylpyridoxine in mouse hippocampusView study →}. So the same molecule can block the GABA receptor while defending the brain’s GABA supply.

The resolution is that bilobalide’s net CNS effect is dose- and context-dependent: receptor-level antagonism at high concentrations versus GAD-mediated GABA preservation and anti-excitotoxic protection at the doses used in neuroprotection studies ^{4,7,8Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 7Sasaki K et al. · 1999AnimalEffects of bilobalide on gamma-aminobutyric acid levels and glutamic acid decarboxylase in mouse brainView study →Reference 8Sasaki K et al. · 2000AnimalBilobalide prevents reduction of gamma-aminobutyric acid levels and glutamic acid decarboxylase activity induced by 4-O-methylpyridoxine in mouse hippocampusView study →}. It is a clean illustration of why receptor pharmacology alone does not predict a whole-tissue outcome — and why the safety note (proconvulsant ceiling) and the therapeutic interest (neuroprotection) are both real.

What It's Used For

Bilobalide’s preclinical profile is broad and mechanistically coherent, but the load-bearing caveat holds throughout: it is nearly all isolated-molecule work in rodents and cell models, with the human record belonging to the whole extract ^{1,11Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 11Feng Z et al. · 2019ReviewThe neuroprotective mechanisms of ginkgolides and bilobalide in cerebral ischemic injury: a literature reviewView study →}.

Evidence by IndicationStrength of support · Beta

Support is an experimental score — weighted by study type (human > animal > in vitro) and volume. A beta, not a validated metric. All human efficacy data are the extract, not the isolate, so isolate scores stay modest by design.

01Neuroprotection (Cerebral Ischemia)Shaky44%Extensive rodent/cell isolate models — infarct/edema, ATP, excitotoxicity ^{9,10,11Reference 9Jones FA et al. · 2002Effects of bilobalide on amino acid release and electrophysiology of cortical slicesView study →Reference 10DeFeudis FV · 2002Bilobalide and neuroprotectionView study →Reference 11Feng Z et al. · 2019ReviewThe neuroprotective mechanisms of ginkgolides and bilobalide in cerebral ischemic injury: a literature reviewView study →}

02GABA-A / Glycine AntagonismShaky40%Recombinant + native receptor electrophysiology; defined IC50 ^{4,5,6Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 5Ivic L et al. · 2003Terpene trilactones from Ginkgo biloba are antagonists of cortical glycine and GABA(A) receptorsView study →Reference 6Huang SH et al. · 2006Mixed antagonistic effects of bilobalide at the rho1 GABA(C) receptorView study →}

03Anti-Inflammatory / NeuroinflammationShaky30%Preclinical: ↓ NF-κB, cytokines, microglia ^{1,11Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 11Feng Z et al. · 2019ReviewThe neuroprotective mechanisms of ginkgolides and bilobalide in cerebral ischemic injury: a literature reviewView study →}

04Anti-Apoptotic (PI3K/Akt)Shaky24%Cell model (SH-SY5Y); downstream of neuroprotection ^{12Reference 12Shi C et al. · 2010Bilobalide prevents apoptosis through activation of the PI3K/Akt pathway in SH-SY5Y cellsView study →}

05Metabolic / Anti-Adipogenic (AMPK)Shaky18%Single in-vitro adipocyte study — off the CNS axis ^{13Reference 13Bu S et al. · 2019Bilobalide suppresses adipogenesis in 3T3-L1 adipocytes via the AMPK signaling pathwayView study →}

Mechanisms

The GABA-A antagonism is the load-bearing signature — it, not PAF antagonism, is what separates bilobalide from the ginkgolides. The GAD/GABA-content effect is what keeps a GABA-A antagonist net-neuroprotective rather than net-convulsant at therapeutic doses.

Pharmacokinetics

For a terpene lactone, bilobalide has unusually good oral absorption. In healthy volunteers its absolute oral bioavailability was ~0.79 with an elimination half-life of ~3.2 h after ginkgo dosing — among the highest bioavailability of the ginkgo terpene lactones ^{16Reference 16Fourtillan JB et al. · 1995Pharmacokinetic properties of bilobalide and ginkgolides A and B in healthy subjects after intravenous and oral administration of Ginkgo biloba extract (EGb 761)View study →}. Human single-dose studies of standardized preparations report bilobalide Cmax up to ~27 ng/mL (highest from EGb 761, lower from other formulations) ^{15Reference 15Woelkart K et al. · 2010Pharmacokinetics of bilobalide, ginkgolide A and B after administration of three different Ginkgo biloba L. preparations in humansView study →}. Distribution is wide and elimination relatively slow among the trilactones, with predominantly renal clearance ^{1Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →}. The practical implication mirrors the ginkgolides: even with good fractional absorption, the absolute plasma levels from oral ginkgo (low ng/mL) sit far below the low-µM concentrations at which bilobalide antagonises GABA-A receptors in vitro ^{4,15Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 15Woelkart K et al. · 2010Pharmacokinetics of bilobalide, ginkgolide A and B after administration of three different Ginkgo biloba L. preparations in humansView study →} — so in-vitro receptor potency should not be read straight across to an oral human effect.

Clinical Trials

There are no controlled clinical trials of isolated bilobalide for any indication. The human evidence that gets attached to bilobalide is really the standardized whole-leaf extract EGb 761 (cognition, peripheral circulation, tinnitus), within which bilobalide is one of several actives and the neuroprotective effects are extract-level, not isolate-level ^{1,11Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 11Feng Z et al. · 2019ReviewThe neuroprotective mechanisms of ginkgolides and bilobalide in cerebral ischemic injury: a literature reviewView study →}.

Last checked: July 2026.

How Bilobalide Works

Bilobalide’s neuroprotection is not one mechanism but a convergent set, which is why it survives loss of any single pathway.

GABAergic & Glycinergic Modulation

At the receptor level bilobalide antagonises GABA-A and glycine receptors, reducing inhibitory chloride currents ^{4,5Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 5Ivic L et al. · 2003Terpene trilactones from Ginkgo biloba are antagonists of cortical glycine and GABA(A) receptorsView study →}. Separately, it raises whole-brain GABA by boosting GAD activity and protects the GABA pool against depletion ^{7,8Reference 7Sasaki K et al. · 1999AnimalEffects of bilobalide on gamma-aminobutyric acid levels and glutamic acid decarboxylase in mouse brainView study →Reference 8Sasaki K et al. · 2000AnimalBilobalide prevents reduction of gamma-aminobutyric acid levels and glutamic acid decarboxylase activity induced by 4-O-methylpyridoxine in mouse hippocampusView study →}. The two act on different levels (receptor vs. neurotransmitter supply), producing the dose-dependent balance described in the anticonvulsant paradox above.

Mitochondrial Protection

A core, distinctive feature: bilobalide preserves mitochondrial ATP synthesis and respiratory function under ischemic and toxic stress, helping neurons hold their energy charge through an insult ^{10Reference 10DeFeudis FV · 2002Bilobalide and neuroprotectionView study →}. This mitochondrial angle is much more prominent for bilobalide than for the PAF-antagonist ginkgolides.

Anti-Excitotoxicity

By lowering the release of excitatory amino acids (glutamate, aspartate) ^{9Reference 9Jones FA et al. · 2002Effects of bilobalide on amino acid release and electrophysiology of cortical slicesView study →} and blunting downstream excitotoxic cascades, bilobalide reduces the glutamate-driven neuronal death that follows ischemia — the upstream node that ties several of its downstream effects together.

Anti-Apoptotic & Anti-Inflammatory Signalling

Downstream, bilobalide activates PI3K/Akt survival signalling ^{12Reference 12Shi C et al. · 2010Bilobalide prevents apoptosis through activation of the PI3K/Akt pathway in SH-SY5Y cellsView study →} and suppresses NF-κB-mediated neuroinflammation (cytokines, microglial activation) ^{1,11Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 11Feng Z et al. · 2019ReviewThe neuroprotective mechanisms of ginkgolides and bilobalide in cerebral ischemic injury: a literature reviewView study →}, reinforcing neuronal survival after the initial insult.

Isolate vs. Plant Studies

Bilobalide sits at the honest end of the isolate-vs-plant spectrum. The mechanistic and neuroprotection work is overwhelmingly the isolated molecule — the GABA-A/glycine electrophysiology ^{4,5,6Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 5Ivic L et al. · 2003Terpene trilactones from Ginkgo biloba are antagonists of cortical glycine and GABA(A) receptorsView study →Reference 6Huang SH et al. · 2006Mixed antagonistic effects of bilobalide at the rho1 GABA(C) receptorView study →}, the GAD/GABA-content studies ^{7,8Reference 7Sasaki K et al. · 1999AnimalEffects of bilobalide on gamma-aminobutyric acid levels and glutamic acid decarboxylase in mouse brainView study →Reference 8Sasaki K et al. · 2000AnimalBilobalide prevents reduction of gamma-aminobutyric acid levels and glutamic acid decarboxylase activity induced by 4-O-methylpyridoxine in mouse hippocampusView study →}, the excitatory-amino-acid work ^{9Reference 9Jones FA et al. · 2002Effects of bilobalide on amino acid release and electrophysiology of cortical slicesView study →}, the PI3K/Akt cell study ^{12Reference 12Shi C et al. · 2010Bilobalide prevents apoptosis through activation of the PI3K/Akt pathway in SH-SY5Y cellsView study →} and the AMPK adipocyte study ^{13Reference 13Bu S et al. · 2019Bilobalide suppresses adipogenesis in 3T3-L1 adipocytes via the AMPK signaling pathwayView study →} all test purified bilobalide, which makes it a strong preclinical isolate base. The human evidence, by contrast, is entirely the whole extract: EGb 761’s cognition, circulatory and tinnitus trials are extract results in which bilobalide is one standardized marker among many, and the extract’s neuroprotection is attributed to the flavonol glycosides and bilobalide together, not to this molecule alone ^{1,11Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 11Feng Z et al. · 2019ReviewThe neuroprotective mechanisms of ginkgolides and bilobalide in cerebral ischemic injury: a literature reviewView study →}. The correct read is therefore: robust isolate mechanism + real whole-extract clinical evidence + no direct human isolate efficacy — the two are not interchangeable.

Its Role in Plants

Bilobalide is biosynthesised through the plastidial MEP (methylerythritol-phosphate) terpenoid pathway that also builds the ginkgolides. Although it is a C15 sesquiterpene, it is thought to arise from a diterpenoid (ginkgolide-type) precursor by degradative loss of carbons rather than from a conventional sesquiterpene route — a “degraded diterpene” origin consistent with its shared caged trilactone skeleton and the rare tert-butyl group it holds in common with the ginkgolides ^{1,2Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 2van Beek TA · 2005Ginkgolides and bilobalide: their physical, chromatographic and spectroscopic propertiesView study →}.

Functionally, the ginkgo terpene lactones are regarded as defensive metabolites — deterring insects and other herbivores — which fits their concentration in the leaves and the tree’s famous resistance to pests. These are plant-biology roles and do not, on their own, predict human pharmacology.

Prevalence in Nature

Bilobalide is, for practical purposes, unique to Ginkgo biloba — a living-fossil gymnosperm with no close relatives — and is one of the marker compounds used to authenticate genuine ginkgo material ^{1,2Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 2van Beek TA · 2005Ginkgolides and bilobalide: their physical, chromatographic and spectroscopic propertiesView study →}. It occurs chiefly in the leaves and is concentrated in the standardized leaf extract, where it is the single most abundant terpene trilactone: EGb 761 is standardized to ~24% flavonol glycosides and ~6% terpene lactones, and within that terpene fraction bilobalide runs at roughly 2.6–3.2% of the extract, comparable to the combined ginkgolides ^{1,3Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 3DeFeudis FV · 2000Ginkgo biloba extract (EGb 761) and CNS functions: basic studies and clinical applicationsView study →}. It is not found at meaningful levels in other plants, which is exactly why its detection is a fingerprint for ginkgo adulteration testing ^{2Reference 2van Beek TA · 2005Ginkgolides and bilobalide: their physical, chromatographic and spectroscopic propertiesView study →}.

Discovery & Synthesis

Bilobalide was isolated from Ginkgo biloba leaves and its structure elucidated by Koji Nakanishi and colleagues around 1967–1971, close on the heels of the ginkgolides they had characterised — the name simply marks its botanical origin (Ginkgo biloba) ^{2Reference 2van Beek TA · 2005Ginkgolides and bilobalide: their physical, chromatographic and spectroscopic propertiesView study →}. Its densely oxygenated, caged trilactone framework with a tert-butyl group made it a landmark target for synthetic chemistry: E. J. Corey reported the first total synthesis in 1987, and the molecule has remained a benchmark ever since, most recently in a concise asymmetric synthesis by Shenvi and co-workers (2019) and related mechanistic-synthesis programmes that resynthesised bilobalide specifically to interrogate its GABAergic targets ^{5,17Reference 5Ivic L et al. · 2003Terpene trilactones from Ginkgo biloba are antagonists of cortical glycine and GABA(A) receptorsView study →Reference 17Baker MA et al. · 2019Concise asymmetric synthesis of (−)-bilobalideView study →}.

Manufacture today is not by total synthesis — the laboratory routes are elegant but far too complex to compete commercially. Practical supply is extraction and enrichment from ginkgo leaves, as the standardized terpene-lactone fraction of EGb 761-type extracts; isolated bilobalide is a research chemical, not a bulk commodity ^{1,2Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →Reference 2van Beek TA · 2005Ginkgolides and bilobalide: their physical, chromatographic and spectroscopic propertiesView study →}.

Patents: not yet researched.

Toxicity & Safety

Bilobalide carries a low toxicity flag: within standardized ginkgo extracts it is consumed at a few milligrams a day and those extracts are generally well tolerated, and the isolate shows a wide margin in animal studies ^{1Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →}. Two mechanism-linked cautions keep it off “harmless,” and neither is well quantified in humans.

Safety at a Glance

✅ Low / no toxicityBleeding risk

• Low toxicity at extract-level exposure. Bilobalide is a well-characterized marker of standardized ginkgo leaf extract, consumed at milligram levels with a good tolerability record ^{1Reference 1Lu J et al. · 2021ReviewBilobalide: a review of its pharmacology, pharmacokinetics, toxicity, and safetyView study →}.
• Not the allergenic or seed-toxin fractions. It is distinct from the allergenic ginkgolic acids and from the seizure-inducing seed neurotoxin ginkgotoxin (4′-O-methylpyridoxine) — against which it is actually protective ^{8Reference 8Sasaki K et al. · 2000AnimalBilobalide prevents reduction of gamma-aminobutyric acid levels and glutamic acid decarboxylase activity induced by 4-O-methylpyridoxine in mouse hippocampusView study →}.
• Theoretical proconvulsant ceiling. As a GABA-A/glycine-receptor antagonist it could in principle lower seizure threshold at high exposure, even though at therapeutic doses its GAD/GABA effects run the other way ^{4,5Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 5Ivic L et al. · 2003Terpene trilactones from Ginkgo biloba are antagonists of cortical glycine and GABA(A) receptorsView study →}.
• Whole-extract bleeding caution carries over. Ginkgo extract can add to antiplatelet/anticoagulant effects — this is chiefly the PAF-antagonist ginkgolides, not bilobalide, but applies to any ginkgo product bilobalide comes in ^{3Reference 3DeFeudis FV · 2000Ginkgo biloba extract (EGb 761) and CNS functions: basic studies and clinical applicationsView study →}.
• No isolate human safety data. No dedicated human toxicology, interaction or reproductive dataset exists for purified bilobalide; safety is inferred from the extract.

Full Safety & Interactions Detail

Within standardized ginkgo leaf extract, bilobalide is one of the better-characterized and better-tolerated constituents, and it is not the source of ginkgo’s main safety flags — it is distinct from the allergenic/cytotoxic ginkgolic acids (a contaminant class capped in quality extracts) and from the seed neurotoxin ginkgotoxin, which bilobalide actually counteracts by defending brain GABA ^{8Reference 8Sasaki K et al. · 2000AnimalBilobalide prevents reduction of gamma-aminobutyric acid levels and glutamic acid decarboxylase activity induced by 4-O-methylpyridoxine in mouse hippocampusView study →}.

Its own mechanism-linked concern is the GABA-A/glycine antagonism: because blocking inhibitory neurotransmission is normally proconvulsant, high-concentration exposure carries a theoretical seizure-threshold caution — offset at ordinary doses by its GAD-mediated rise in GABA content and anti-excitotoxic action, but worth noting for anyone with a seizure disorder ^{4,5,7Reference 4Huang SH et al. · 2003Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptorsView study →Reference 5Ivic L et al. · 2003Terpene trilactones from Ginkgo biloba are antagonists of cortical glycine and GABA(A) receptorsView study →Reference 7Sasaki K et al. · 1999AnimalEffects of bilobalide on gamma-aminobutyric acid levels and glutamic acid decarboxylase in mouse brainView study →}.

The familiar bleeding/antiplatelet caution for ginkgo (additive risk with anticoagulants, antiplatelets and NSAIDs, especially perioperatively) is driven mainly by the PAF-antagonist ginkgolides, not by bilobalide, but it applies to any whole-extract product in which bilobalide is delivered ^{3Reference 3DeFeudis FV · 2000Ginkgo biloba extract (EGb 761) and CNS functions: basic studies and clinical applicationsView study →}.

No dedicated human interaction, repeat-dose or reproductive-toxicity dataset exists for the isolate; pregnancy/lactation decisions belong to the ginkgo herb page and the specific product, where intake is decided, not to this molecule page.

Dosage

There is no established human dose for isolated bilobalide — it has never been trialled as an isolate. Human exposure is indirect, through standardized ginkgo leaf extract: EGb 761-type products at 120–240 mg/day are standardized to ~6% terpene lactones and deliver only a few milligrams of bilobalide, reaching low ng/mL plasma levels ^{15,16Reference 15Woelkart K et al. · 2010Pharmacokinetics of bilobalide, ginkgolide A and B after administration of three different Ginkgo biloba L. preparations in humansView study →Reference 16Fourtillan JB et al. · 1995Pharmacokinetic properties of bilobalide and ginkgolides A and B in healthy subjects after intravenous and oral administration of Ginkgo biloba extract (EGb 761)View study →}. Preclinical neuroprotection figures in the literature are animal research doses (typically several to tens of mg/kg in rodent ischemia models) and are not convertible to human self-dosing ^{10,11Reference 10DeFeudis FV · 2002Bilobalide and neuroprotectionView study →Reference 11Feng Z et al. · 2019ReviewThe neuroprotective mechanisms of ginkgolides and bilobalide in cerebral ischemic injury: a literature reviewView study →}. These are research figures, not a personal recommendation.

References

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4. Huang SH, Duke RK, Chebib M, Sasaki K, Wada K, Johnston GAR (2003). Bilobalide, a sesquiterpene trilactone from Ginkgo biloba, is an antagonist at recombinant alpha1beta2gamma2L GABA(A) receptors. European Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/12600688/
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7. Sasaki K, Hatta S, Haga M, Ohshika H (1999). Effects of bilobalide on gamma-aminobutyric acid levels and glutamic acid decarboxylase in mouse brain. European Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/10078989/
8. Sasaki K, Hatta S, Wada K, Ohshika H, Haga M (2000). Bilobalide prevents reduction of gamma-aminobutyric acid levels and glutamic acid decarboxylase activity induced by 4-O-methylpyridoxine in mouse hippocampus. Life Sciences. https://pubmed.ncbi.nlm.nih.gov/12659176/
9. Jones FA, Chatterjee SS, Davies JA (2002). Effects of bilobalide on amino acid release and electrophysiology of cortical slices. Amino Acids. https://pubmed.ncbi.nlm.nih.gov/12107763/
10. DeFeudis FV (2002). Bilobalide and neuroprotection. Pharmacological Research. https://pubmed.ncbi.nlm.nih.gov/12457632/
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12. Shi C, Wu F, Yew DT, Xu J, Zhu Y (2010). Bilobalide prevents apoptosis through activation of the PI3K/Akt pathway in SH-SY5Y cells. Apoptosis. https://pubmed.ncbi.nlm.nih.gov/20333467/
13. Bu S, Yuan CY, Xue Q, Chen Y, Cao F (2019). Bilobalide suppresses adipogenesis in 3T3-L1 adipocytes via the AMPK signaling pathway. Molecules. https://pubmed.ncbi.nlm.nih.gov/31569605/
14. Zhang Y, Zhai Q (2020). Bilobalide assuages morphine-induced addiction in hippocampal neuron cells through upregulation of microRNA-101. Journal of Biochemical and Molecular Toxicology. https://pubmed.ncbi.nlm.nih.gov/32319158/
15. Woelkart K, Feizlmayr E, Dittrich P, et al. (2010). Pharmacokinetics of bilobalide, ginkgolide A and B after administration of three different Ginkgo biloba L. preparations in humans. Phytotherapy Research. https://pubmed.ncbi.nlm.nih.gov/20041430/
16. Fourtillan JB, Brisson AM, Girault J, et al. (1995). Pharmacokinetic properties of bilobalide and ginkgolides A and B in healthy subjects after intravenous and oral administration of Ginkgo biloba extract (EGb 761). Thérapie. https://pubmed.ncbi.nlm.nih.gov/7631288/
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