Synapsin

Compounded intranasal blend of ginsenoside Rg3 + nicotinamide riboside (NR) — not Rg3 + ALCAR as Dylan's brief stated; the canonical Synapsin formulation is Rg3+NR, with optional pharmacy add-ons (B12, alpha-GPC). Marketed for neuroinflammation, brain fog, and cognitive support via olfactory nose-to-brain delivery. For Dylan: SKIP-FOR-NOW (LOW confidence) — the mechanism is biologically plausible (real microglial M1→M2 + NAD+-floor effects), but the Synapsin-specific human evidence is zero published RCTs, and Cerebrolysin already covers the same neuroprotection thesis with decades of multi-group trials. Pencil it in as a contingency if Cerebrolysin sourcing collapses or needle aversion shows up; otherwise the slot is taken.

Synapsin is a US compounded intranasal product. The core "Synapsin powder" is a patent-pending blend of ginsenoside Rg3 + nicotinamide riboside (NR) (originally developed by Jim LaValle, RPh). Compounding pharmacies dissolve the powder into a saline-based nasal spray, often with optional add-ons: methylcobalamin (B12), alpha-GPC, or methyl-folate. ALCAR is NOT a standard Synapsin component (a few pharmacies do offer custom Rg3+ALCAR blends, but the canonical product is Rg3+NR; this is an accuracy flag against the task brief).

Why intranasal: the olfactory and trigeminal nerve pathways provide direct nose-to-brain transport, bypassing first-pass liver metabolism and the systemic blood-brain barrier. This is the same delivery rationale used for Semax, Selank, intranasal insulin, and intranasal oxytocin — well-established in principle, less well-quantified for these specific molecules.

Component mechanisms:

1. Ginsenoside Rg3 — microglial modulation. Rg3 is a triterpene saponin from Panax ginseng. In rodent models (LPS challenge, TBI, PTSD):

   • Suppresses M1 (pro-inflammatory) microglial phenotype, promotes M2 (anti-inflammatory / phagocytic) phenotype.
   • Inhibits NF-κB pathway via SIRT1 activation; downregulates TNF-α, IL-1β, IL-6, iNOS, COX-2.
   • Upregulates FGFR1 in microglia → suppresses excessive activation, reduces neuronal apoptosis.
   • Enhances microglial clearance of amyloid-β via type A macrophage scavenger receptor.
   • Effective doses in rodents: 20–30 mg/kg systemic (very different exposure from the few-microgram intranasal dose Synapsin delivers — extrapolation hazard).

2. Nicotinamide riboside — NAD+ precursor. NR is a vitamin B3 form that elevates NAD+ levels via the NRK pathway. NAD+ is a coenzyme for sirtuins (SIRT1/3/6), mitochondrial complex I, and PARP-mediated DNA repair. Rationale: aging brain shows NAD+ decline; restoring NAD+ improves mitochondrial efficiency in neurons. Catch: human oral NR trials have not produced cognitive endpoints; intranasal NR pharmacokinetics are essentially uncharacterized in humans.

3. Optional add-ons (methylcobalamin / alpha-GPC / methyl-folate): these have their own evidence stacks (B12 for nerve health; alpha-GPC as cholinergic precursor) but are tangential to the Rg3+NR neuroprotection thesis.

Plain English: It tells microglia to calm down (Rg3) and gives mitochondria more fuel currency (NR). Both mechanisms are real and well-characterized in cells/rodents at high systemic doses. The unanswered question is whether intranasal microgram doses recapitulate that effect in human brain tissue — and there is no published trial to settle it.