I. Basic Information

Chemical Structure: Composed of 7 amino acids with the sequence Met - Glu - His - Phe - Pro - Gly - Pro - NH2, it is an analog of thyrotropin - releasing hormone (TRH), but has stronger activity and neuro - specificity.

CAS Number: 167412 - 21 - 9.

Molecular Weight: Approximately 786.9 g/mol.

II. Mechanism of Action

Semax exerts its effects by acting on multiple targets in the central nervous system:

1.Regulation of Neurotransmitters:

Enhances the release of dopamine, norepinephrine, and serotonin, improving mood and cognitive function.

Inhibits the activity of acetylcholinesterase, increases the level of acetylcholine, and promotes learning and memory.

2.Neuroprotection:

Reduce oxidative stress and inflammatory responses, protecting neurons from ischemia, trauma, or toxin damage. Promote neuroplasticity and synapse formation, potentially accelerating the repair after brain injury.

Promote neuroplasticity and synapse formation, potentially accelerating the repair after brain injury.

3.Influence stress response:

Lower cortisol levels, relieve anxiety and stress, and enhance the function of the hippocampus (related to memory formation) at the same time.

III. Potential Applications and Research

1.Neurological Diseases

·Ischemic Stroke: Animal experiments have shown that Semax can reduce the area of cerebral infarction and improve neurological deficits, possibly by promoting angiogenesis and inhibiting neuronal   apoptosis.

·Traumatic Brain Injury (TBI): It can reduce brain edema and inflammation, and promote the recovery of motor and cognitive functions.

·Alzheimer's Disease and Cognitive Impairment: By enhancing the cholinergic system and clearing β-amyloid protein deposition, it can improve memory and learning abilities (in the early research stage).

2.Psychiatric and Psychological Fields

·Depression and Anxiety Disorders: It can increase the levels of monoamine neurotransmitters, relieve low mood and anxiety symptoms, and may take effect faster than traditional antidepressants.

·Chronic Fatigue Syndrome: It can improve fatigue and cognitive decline, and regulate the imbalance of the hypothalamic-pituitary-adrenal axis (HPA axis).

3.Cognitive Enhancement and Applications in Healthy Populations

·Improving Attention and Memory: Studies on healthy subjects have shown that Semax can improve working memory, verbal fluency, and visuospatial abilities, especially more significantly under stress or   sleep deprivation.

·Enhancing Athletic Performance: It may improve athletes' reaction speed and endurance by regulating neuromuscular coordination and reducing fatigue.

IV. Administration Routes and Dosages

Intranasal Spray: The most commonly used route, with a bioavailability of approximately 10 - 15%. Onset of action is 15 - 30 minutes, and the effect lasts for 4 - 6 hours.

Subcutaneous Injection: Faster onset of action (5 - 10 minutes), but intranasal spray is more convenient in clinical studies.

Dosage Range:

Usual Adult Dosage: Intranasal spray, 80 - 160 µg (0.08 - 0.16 mg) per administration, 1 - 2 times a day, and the treatment course is usually 2 - 4 weeks.

When treating stroke or severe brain injury, higher dosages or intravenous administration may be required.