What Is Selank?

Selank is a synthetic peptide derived from tuftsin, a naturally occurring immunomodulatory peptide. Clinically, Selank is best known for its reduction in anxiety and stabilizing effects without sedation.

How Selank Works

Selank primarily modulates the GABAergic system, which plays a central role in regulating anxiety, stress response, and emotional balance. Rather than forcing neurotransmitter release, Selank appears to influence gene expression related to inhibitory signaling, helping calm an overactive nervous system.

Common Effects of Selank

• Reduced baseline anxiety and stress reactivity
• Improved emotional regulation
• Less “mental noise” without dulling cognition
• No dependency or withdrawal profile seen with traditional anxiolytics

Selank is often chosen by patients who feel wired, overstimulated, or chronically anxious, especially when stress interferes with sleep, focus, or recovery.

What Is Semax?

Semax is a synthetic analog of ACTH (4–10) and is primarily used for cognitive enhancement and neuroplasticity. It has been studied extensively in Eastern Europe for its effects on learning, memory, and recovery from neurological stress.

How Semax Works

Semax is best known for increasing brain-derived neurotrophic factor (BDNF). BDNF plays a key role in synaptic plasticity, neuronal repair, and long-term learning. In simple terms, Semax supports the brain’s ability to build, reinforce, and optimize neural connections.

Common Effects of Semax

• Improved focus and mental endurance
• Enhanced memory and learning capacity
• Increased cognitive resilience under stress
• A subjective feeling of mental sharpness or clarity

Semax is often selected by patients optimizing for performance, productivity, and cognitive longevity, especially during periods of high mental demand.

How does it compare to SSRIs?

• SSRIs work primarily by inhibiting the serotonin transporter (SERT), which increases serotonin availability in synapses.
• Selank’s best-described mechanistic evidence includes changes in gene expression in pathways involved in neurotransmission, including GABAergic-related genes, in rodent brain after intranasal administration.
• Semax is an analogue of the ACTH(4–10) fragment and has preclinical evidence suggesting effects on neurotrophin pathways such as BDNF/TrkB.
• Both Semax and Selank have human-serum in-vitro evidence of inhibiting enkephalin-degrading enzymes (i.e., they can slow breakdown of endogenous enkephalins in a lab setting), but the clinical significance of this mechanism is not automatically established by in-vitro findings alone.

Clinical Evidence for Selank

Selank’s anxiolytic effects in patients with anxiety disorders

• Clinical studies have shown that Selank has antianxiety and neuroprotective effects in the treatment of generalized anxiety disorders (GAD) and related conditions, and that its anxiolytic effect is comparable to classical anxiolytic medications in human participants.
• A small clinical study in patients with GAD found increases in anxiety-related parameters with Selank treatment, supporting its real-world anxiolytic use.

Clinical Evidence for Semax

Semax’s cognitive and neuroplastic effects in humans

• In human research, intranasal Semax improved attention and short-term memory in healthy subjects working extended hours, with effects lasting into the next day after administration.
• A clinical study in patients recovering from ischemic stroke showed that Semax administration increased BDNF levels and was correlated with better functional recovery and motor performance, suggesting durable neuroplastic effects linked to treatment.

Selank: GABAergic modulation, neuropeptides, and immune signaling

Gene-expression effects consistent with GABA system modulation

• A well-cited rodent study found Selank altered expression of genes involved in neurotransmission after administration, and the authors’ data supported a possible allosteric relationship with the GABAergic system.

Enkephalinase inhibition (endogenous opioid peptide regulation)

• Human-serum enzyme studies reported Semax and Selank can inhibit enzymes involved in enkephalin degradation. One paper specifically proposed Selank’s enkephalinase inhibition as a possible anxiolytic mechanism.

Immunomodulatory / cytokine effects in humans

• A clinical study in patients with generalized anxiety disorder/neurasthenia reported shifts in Th1/Th2 cytokine balance after 14 days of Selank, suggesting a neuroimmune signal may be part of its profile.

Semax: neurotrophins (BDNF/NGF), gene expression, and neuroprotection

BDNF/TrkB association in preclinical work

• A classic Semax paper (rodent) suggests Semax modulates BDNF/TrkB expression in the hippocampus, a common rationale for its “plasticity” narrative.

Neurotrophin gene-expression changes in ischemia models

• Work in stroke models reports Semax (and its fragment PGP) influences expression of neurotrophins and related receptors post-ischemia.

Why intranasal delivery is a big part of the conversation

Many peptides are broken down quickly in the GI tract and do not absorb well orally. Intranasal delivery is often used in research and clinical contexts because it can provide a non-invasive route that may reach the central nervous system via olfactory and trigeminal pathways, partially bypassing the blood–brain barrier (BBB).

Do Effects Last After Stopping?

Selank’s calming effects are largely state-dependent—meaning the direct anxiolytic effect fades after discontinuation. However, when combined with lifestyle changes (sleep, stress management, therapy, training), many patients notice a lower baseline anxiety over time.

Availability

Bowery Clinic’s Semax + Selank programs are available through clinician evaluation with a defined monitoring plan and outcome tracking. Candidates are assessed individually, with care plans tailored to history, labs, and goals.

To learn more or request a clinical consult, patients can contact Bowery Clinic for an intake and physician review. Bowery Clinic provides peptide telehealth services to patients in New York, Florida, Michigan, Arizona, Washington, Illinois, New Jersey, California, Georgia, and Pennsylvania.

Bowery Clinic works exclusively with licensed 503A compounding pharmacies to ensure every medication meets the highest safety, purity, and sterility standards. We do not use or endorse research-grade peptides in any form, as they are not manufactured for human use and lack the regulatory protections required for safe medical treatment.