Quick Comparison
| Ginkgo Biloba | Zinc | |
|---|---|---|
| Half-Life | 3-10 hours (varies by constituent) | Tissue zinc turns over over weeks |
| Typical Dosage | Standard: 120-240 mg daily of standardized extract (24% flavone glycosides, 6% terpene lactones). EGb 761 is the most studied form. Often taken in 2-3 divided doses. | Standard: 15-30 mg elemental zinc daily. Do not exceed 40 mg daily long-term (can cause copper depletion). Zinc picolinate, zinc bisglycinate, and zinc carnosine are well-absorbed forms. Zinc oxide is poorly absorbed. Take with food to reduce nausea. If supplementing >15 mg daily, add 1-2 mg copper. |
| Administration | Oral (capsules, tablets, liquid extract). Standardized extract recommended over raw leaves. | Oral (capsules, tablets, lozenges). Take with food. Zinc picolinate or bisglycinate for best absorption. |
| Research Papers | 9 papers | 9 papers |
| Categories |
Mechanism of Action
Ginkgo Biloba
Ginkgo biloba extract (EGb 761) contains flavonoids (quercetin, kaempferol, isorhamnetin) and terpenoids (ginkgolides A, B, C, J and bilobalide). The flavonoids are potent antioxidants that scavenge superoxide, hydroxyl radicals, and peroxynitrite, and protect neurons from oxidative damage; they may also chelate iron. The terpenoids (ginkgolides and bilobalide) improve blood flow by antagonizing platelet-activating factor (PAF) at the PAF receptor, which reduces platelet aggregation, blood viscosity, and improves microcirculation in the brain. Bilobalide protects mitochondria and reduces apoptosis. Ginkgo modulates nitric oxide (NO) availability via endothelial nitric oxide synthase (eNOS) for vasodilation. It inhibits monoamine oxidase A and B (MAO-A, MAO-B), mildly elevating dopamine and serotonin. It may enhance cholinergic transmission and reduce amyloid aggregation.
Zinc
Zinc is released from synaptic vesicles (via ZnT3 transporter) during neurotransmission from glutamatergic mossy fiber and Schaffer collateral terminals. It modulates NMDA receptors — at high concentrations zinc blocks the channel at a distinct site from Mg2+, while at low concentrations it potentiates via the GluN2A subunit. Zinc modulates GABA-A receptors (positive allosteric at alpha1, negative at alpha2/3) and glycine receptors. It is required for BDNF synthesis (zinc finger transcription factors) and TrkB signaling. Zinc-dependent enzymes include carbonic anhydrase (CAII, pH regulation), Cu/Zn superoxide dismutase (SOD1, antioxidant defense), and matrix metalloproteinases (synaptic remodeling). In the hippocampus, zinc modulates long-term potentiation (LTP) via CaMKII and MAPK/ERK pathways — the cellular basis of memory formation. Zinc also regulates presynaptic vesicle release.
Risks & Safety
Ginkgo Biloba
Common
Headache, dizziness, gastrointestinal discomfort, allergic skin reactions.
Serious
Increased bleeding risk — do not combine with blood thinners (warfarin, aspirin) or take before surgery.
Rare
Seizures (particularly with raw seeds, not standardized extract), severe allergic reactions.
Zinc
Common
Nausea on empty stomach, metallic taste.
Serious
Long-term high-dose use (>40 mg daily) depletes copper, causing anemia and neurological problems.
Rare
Headache, diarrhea, reduced immune function (paradoxically) at very high doses.
Full Profiles
Ginkgo Biloba →
One of the oldest living tree species on Earth, used in traditional Chinese medicine for millennia. Ginkgo extract (EGb 761) is one of the most prescribed herbal medicines in Europe for cognitive decline and cerebrovascular insufficiency. It improves cerebral blood flow, has antioxidant properties, and modulates neurotransmitter systems. Most effective in older adults with declining cognitive function.
Zinc →
An essential trace mineral concentrated in the brain's hippocampus, where it plays a critical role in synaptic transmission and memory formation. Zinc modulates NMDA and GABA receptors, supports BDNF expression, and is required for proper neurotransmitter release. Deficiency is common (estimated 17-25% of the global population) and directly impairs memory, attention, and mood.