Research goal
Neuroprotection
Covers compounds researched for their ability to protect neurons from oxidative stress, excitotoxicity, and age-related degeneration, and to support neuroplasticity and neurotrophic factor expression.
Relevant Compounds
| Compound | Class | Primary mechanism | Commonly reported for | Link |
|---|---|---|---|---|
| Semax | ACTH analogue | BDNF/GDNF upregulation; neuroprotective in stroke/TBI models; antioxidant gene expression | Neuroprotection, cognitive support, stroke recovery | View profile → |
| Selank | Anxiolytic peptide | BDNF upregulation; GABAergic modulation; reduces neuroinflammation | Neuroprotection, anxiolytic, neuroinflammation | View profile → |
| SS-31 | Mitochondria-targeting peptide | Cardiolipin protection; reduces mitochondrial ROS; prevents neuronal apoptosis | Mitochondrial protection, neuroprotection, cardiac support | View profile → |
| NAD+ | Dinucleotide coenzyme | PARP-mediated DNA repair; SIRT1 neuroprotection; NAD+ depletion in neurodegeneration | Neuroprotection, longevity, anti-inflammatory | View profile → |
Research Context
Brain-derived neurotrophic factor (BDNF) is a key regulator of neuronal survival, synaptic plasticity, and the brain's capacity to form and consolidate new connections. Research has investigated both Semax and Selank for their potential role in upregulating BDNF expression — Semax through its ACTH-derived sequence's effects on neurotrophic factor gene transcription, and Selank through a related but distinct pathway that also involves GABAergic modulation. Elevated BDNF is associated with neuroprotection in models of stroke, traumatic brain injury, and neurodegeneration, making BDNF-upregulating compounds a focus of interest across both acute and chronic neural protection research.
SS-31's neuroprotective mechanism operates at the mitochondrial level, specifically through its interaction with cardiolipin — a phospholipid unique to the inner mitochondrial membrane that is critical for the structural integrity of the electron transport chain. Cardiolipin peroxidation by reactive oxygen species (ROS) is an early event in neuronal apoptosis cascades, and SS-31 has been shown in preclinical studies to bind cardiolipin and reduce mitochondrial ROS production. This positions SS-31 as a compound with relevance to any neurodegenerative context in which mitochondrial dysfunction and oxidative stress are implicated, including models of Parkinson's disease, Alzheimer's disease, and ischaemia-reperfusion injury.
NAD+ depletion in neural tissue is increasingly recognised as a feature of both normal ageing and neurodegenerative disease. PARP enzymes — activated by oxidative DNA damage — consume NAD+ as a substrate, and their overactivation following excitotoxic injury or chronic oxidative stress can critically reduce intracellular NAD+ levels in neurons. SIRT1, a NAD+-dependent deacetylase, has been shown to exert neuroprotective effects partly through deacetylation of p53 (preventing apoptotic signalling) and suppression of NF-κB (reducing neuroinflammation). Research has investigated NAD+ restoration via precursors as a strategy to support these protective pathways in neural tissue.
Compound Notes
Semax
Semax is a synthetic heptapeptide derived from the ACTH(4–10) sequence, developed and clinically registered in Russia for use in stroke and TBI settings. It has a well-documented preclinical profile for BDNF and GDNF upregulation, and Russian clinical data has investigated its potential role in post-stroke neuroprotection and cognitive recovery. The nasal route of administration — which bypasses the blood-brain barrier via olfactory epithelium absorption — is the primary delivery method in both clinical and research use. Semax also exhibits antioxidant gene expression effects relevant to neural oxidative stress contexts.
Selank
Selank's neuroprotective profile is closely tied to its BDNF-upregulating activity, which it shares with Semax but through a partially distinct upstream pathway. Additionally, Selank's GABAergic modulation reduces excitotoxic stress — a key driver of neuronal death in acute injury and chronic neurodegeneration. Research has also investigated Selank for its potential role in reducing neuroinflammation via cytokine normalisation. Its dual anxiolytic-neuroprotective profile is unusual among research peptides, and it represents a compound with overlapping relevance across cognitive support, neuroprotection, and immune goals.
SS-31
SS-31 (also known as Elamipretide) is a mitochondria-targeting tetrapeptide with documented effects on cardiolipin stabilisation and ROS reduction within the inner mitochondrial membrane. While much of its published clinical research has focused on cardiac applications, its mechanism is directly relevant to neuronal biology: neurons are among the highest-energy-demand cells in the body, making mitochondrial dysfunction particularly damaging in neural tissue. Research has investigated SS-31 for its potential role in preventing neuronal apoptosis in oxidative injury models. Reported side effects in research and anecdotal accounts include injection-site reactions and mild systemic effects at higher doses.
NAD+
In the context of neuroprotection, NAD+ functions primarily through the PARP repair axis and sirtuin-mediated gene regulation. PARP-1 activation after neural oxidative damage can consume NAD+ to the point of energy failure and cell death — a process sometimes called "parthanatos." SIRT1 deacetylase activity, which depends on NAD+ availability, provides protection via p53 regulation and NF-κB suppression. Research has investigated NAD+ precursors (NMN, NR) for their potential role in restoring these protective mechanisms in ageing neural tissue and in models of neurodegenerative disease. NAD+ is a coenzyme rather than a peptide, but is commonly grouped with peptide research stacks in the longevity and neuroprotection literature.
Commonly Reported Combinations
Semax and Selank are occasionally reported together in research and anecdotal contexts for a combined neuroprotective and anxiolytic profile — their mechanistic overlap on BDNF upregulation suggests potential additive effects, though no controlled combination studies have been published. The compounds operate through sufficiently distinct receptor and signalling pathways (ACTH-derived vs. GABAergic/tuftsin-derived) that interaction risks appear low, but this is based on mechanistic reasoning rather than empirical safety data.
NAD+ is frequently reported alongside Semax or SS-31 in longevity-focused research stacks given their complementary coverage of neurotrophic, mitochondrial, and sirtuin-axis neuroprotection. No dedicated neuroprotection stacks are formally documented in WikiPeptide's stack pages; refer to related goals for stack documentation.
Frequently Asked Questions
What is BDNF and why does it matter for neuroprotection?
Brain-derived neurotrophic factor is a protein in the neurotrophin family that supports the survival, growth, and differentiation of neurons. It binds primarily to the TrkB receptor and activates downstream signalling pathways that suppress apoptosis, promote synaptic plasticity, and support long-term potentiation — the cellular basis of learning and memory. In neuroprotective contexts, BDNF is particularly important because it can counteract the apoptotic signalling triggered by oxidative stress, excitotoxicity, and ischaemia. Research has investigated BDNF-upregulating compounds like Semax and Selank for their potential role in both acute neuroprotection (e.g., after stroke) and chronic neurodegeneration models.
How does SS-31 protect neurons, and is the mechanism the same as for cardiac tissue?
The core mechanism — cardiolipin binding and ROS reduction at the inner mitochondrial membrane — is the same across tissue types. Cardiolipin is present in mitochondria throughout the body, not exclusively in cardiac cells. In neural tissue, SS-31's protection of the electron transport chain complex activity prevents the energetic collapse and cytochrome c release that trigger the mitochondrial apoptosis pathway. The difference lies in the disease contexts studied: cardiac research has produced more formal clinical trial data (particularly in heart failure), while neural applications remain primarily preclinical. The underlying biology supporting neuroprotective application is the same mechanism that has been validated in cardiac models.
Semax vs Selank for neuroprotection: are they targeting the same mechanisms?
Both compounds upregulate BDNF, but through different upstream signals. Semax acts via ACTH receptor pathways and direct neurotrophic factor gene transcription, with a particularly well-studied effect in ischaemic models where rapid BDNF and GDNF elevation is protective. Selank's BDNF upregulation appears to occur via a separate pathway related to its tuftsin-derived sequence, and its additional GABAergic modulation provides excitotoxicity protection that Semax does not offer. Selank also has a stronger anti-neuroinflammatory cytokine profile. In practice, they address overlapping but non-identical aspects of neuroprotection, which is why anecdotal reports of combined use exist in the research community.
What role does NAD+ play in DNA repair after oxidative neural damage?
When reactive oxygen species cause DNA strand breaks in neurons — a common event in ischaemia, excitotoxicity, and neurodegeneration — PARP-1 is rapidly activated to catalyse the repair process. PARP-1 uses NAD+ as its substrate, cleaving it to generate ADP-ribose for poly-ADP-ribosylation of DNA repair proteins. Under conditions of severe oxidative stress, this process can consume intracellular NAD+ faster than it can be replenished, leading to energy failure and a specific form of cell death. Research has investigated NAD+ restoration as a strategy to maintain PARP function within limits that support repair without triggering energy collapse, and to preserve SIRT1 activity for concurrent anti-inflammatory and anti-apoptotic signalling.