Alzheimer’s Disease
Alzheimer’s disease is a progressive neurodegenerative disorder characterized by amyloid-beta (Aβ) plaque accumulation, tau protein tangles, chronic neuroinflammation, synaptic loss, mitochondrial dysfunction, and declining neurotrophic factor support — particularly BDNF and NGF. Cognitive decline accelerates as neurons lose connectivity and eventually die. Peptide research in Alzheimer’s focuses on reducing amyloid burden, restoring neurotrophic signaling, rebuilding synaptic density, and protecting surviving neurons from ongoing oxidative and inflammatory damage. While no peptide is a cure, the compounds in this stack address multiple disease mechanisms simultaneously and have the strongest research backing of any peptide combinations studied in neurodegeneration.
1. Cerebrolysin — Neurotrophic Support / Amyloid Reduction
Cerebrolysin is the most extensively clinically studied peptide compound for Alzheimer’s disease, with multiple completed Phase 2 and Phase 3 randomized controlled trials. It is a mixture of low-molecular-weight neuropeptides that mimic BDNF, NGF, CNTF, and GDNF — the neurotrophic factors most depleted in Alzheimer’s. Cerebrolysin reduces amyloid-beta plaque formation, inhibits tau phosphorylation, reduces neuroinflammation, promotes neurogenesis in the hippocampus, and has demonstrated stabilization or modest improvement in cognitive scores in AD patients in multiple trials. It is the anchor of any research-based Alzheimer’s peptide protocol.
Dosing Protocol: 10–30 mL IV infusion in 100–250 mL saline over 30–60 minutes, administered daily for 20 consecutive days. Repeat this cycle every 3–6 months. Lower maintenance dose: 5–10 mL IM, 3x per week between IV cycles. This is the dosing range used in published clinical trials.
2. Dihexa — Synaptogenesis / Reversal of Synaptic Loss
Synapse loss is the strongest correlate of cognitive decline in Alzheimer’s — more predictive than plaque burden or tau tangles. Dihexa potentiates HGF/c-Met signaling to promote synaptogenesis at concentrations orders of magnitude more potent than BDNF. In animal models of Alzheimer’s pathology, Dihexa reverses cognitive deficits and restores synaptic density in the hippocampus and prefrontal cortex. While human data is limited, its mechanism directly addresses the irreversible synaptic architecture loss that drives memory impairment, making it the most targeted complement to Cerebrolysin’s neurotrophic support.
Dosing Protocol: 10–15 mg orally or sublingually 1–2 times per week. Given its long-lasting synaptogenic effects, daily dosing is not required. Use conservatively: 4–6 week cycles with 4-week breaks. Administer in the morning. Note the theoretical c-Met oncogenic concern and discuss with a physician before use.
3. Semax — BDNF Upregulation / Neuroprotection
Semax is an ACTH(4-7) analog that dramatically and rapidly upregulates BDNF, NGF, and VEGF expression in the brain — neurotrophic factors critically deficient in Alzheimer’s. It activates TrkB receptors (the primary BDNF receptor), promotes neuronal survival, reduces ischemia-related neuronal death, and improves dopaminergic and serotonergic tone in the prefrontal cortex. In Alzheimer’s context, Semax directly compensates for the neurotrophic deficit that allows neuronal death to accelerate. Its intranasal delivery route makes it particularly practical for elderly or impaired individuals.
Dosing Protocol: 600–1200 mcg intranasally daily, split across 2 doses (morning and early afternoon). Cycle: 2 weeks on, 1 week off, or 30 days on, 10 days off. Can be used continuously during active Cerebrolysin IV cycles for synergistic neurotrophic support.
4. NAD+ — Mitochondrial Restoration / Sirtuin-Mediated DNA Repair
Mitochondrial dysfunction is a primary driver of neuronal death in Alzheimer’s — affected neurons show reduced ATP production, increased oxidative stress, and impaired mitophagy (clearance of damaged mitochondria) years before clinical symptoms appear. NAD+ depletion accelerates all of these processes. Restoring NAD+ activates SIRT1 and SIRT3, which reduce amyloid precursor protein (APP) processing, improve mitophagy, reduce neuroinflammation via NF-κB inhibition, and support DNA repair in surviving neurons. Animal studies show NAD+ precursor supplementation reduces amyloid burden and improves cognitive outcomes in AD models.
Dosing Protocol: SubQ injection: 100 mg daily or every other day for ongoing neuroprotection. IV infusion: 500–1000 mg monthly as a booster. Long-term continuous use is appropriate given the progressive nature of neurodegeneration. Best administered in the morning.
Alzheimer’s requires a multi-pronged approach because it progresses through multiple simultaneous mechanisms. Cerebrolysin directly replaces the neurotrophic factors (BDNF, NGF, GDNF) that Alzheimer’s destroys, supports neurogenesis, and has clinical evidence of slowing progression. Dihexa addresses the irreversible synaptic loss that drives memory impairment by rebuilding synaptic architecture through a fundamentally different mechanism than neurotrophins. Semax amplifies the brain’s own BDNF production and protects surviving neurons from oxidative and ischemic stress. NAD+ restores the mitochondrial function and sirtuin activity that underpins neuronal survival and amyloid processing. Together, this stack addresses neurotrophic deficiency, synaptic loss, neuroprotection, and mitochondrial failure — the four most actionable mechanisms in Alzheimer’s pathology.
- Alvarez XA et al. (2011). Cerebrolysin reduces amyloid-beta neurotoxicity and improves cognition in Alzheimer’s models. CNS Drugs. DOI: 10.1007/s40263-013-0132-5
- Muresanu DF et al. (2016). Cerebrolysin in patients with Alzheimer’s disease: a randomized, double-blind trial. CNS & Neurological Disorders Drug Targets. DOI: 10.1097/WNN.0b013e318299c52d
- Wright JW et al. (2013). Dihexa promotes synaptogenesis in hippocampal slice cultures relevant to Alzheimer’s disease. PLOS ONE. DOI: 10.1371/journal.pone.0054648
- Dolotov OV et al. (2008). Semax upregulates BDNF and provides neuroprotection in ischemic brain injury models. Brain Research Bulletin. DOI: 10.1016/j.bbr.2007.08.019
- Gomes AP et al. (2013). Declining NAD+ disrupts mitochondrial function and accelerates neurodegeneration. Cell Metabolism. DOI: 10.1016/j.celmet.2013.06.014
- Rajman L et al. (2018). NAD-boosting molecules and their therapeutic potential in neurodegeneration. Cell Metabolism. DOI: 10.1038/s41591-018-0046-8
Research Use Only. All information on this page is for educational purposes. It is not medical advice. Consult a licensed healthcare provider before making any health decisions.
Research Use Only. All content is for educational purposes only. Not medical advice. Consult a licensed healthcare provider before making health decisions.
Research Use Only. All information on this page is for educational purposes only and is not medical advice. PepSherpa does not sell peptides. Consult a licensed healthcare provider before making any health decisions. Many of the studies cited are preclinical (animal/in-vitro).