Intranasal Administration
Intranasal administration delivers a peptide through the nasal mucosa, bypassing first-pass liver metabolism. It is used for cognitive peptides like Semax and Selank, with variable bioavailability.
Overview
The nasal mucosa is a thin, highly vascularized membrane lining the nasal cavity that allows small molecules to enter circulation directly. Intranasal administration avoids the digestive tract entirely, preventing enzymatic degradation that limits oral peptide bioavailability. Some peptides can also cross the olfactory epithelium and reach the brain via olfactory nerve pathways, making intranasal delivery interesting for CNS-targeting compounds. Semax and Selank — two nootropic peptides with cognitive and anxiolytic research profiles — are commonly administered intranasally. Bioavailability varies considerably between compounds and depends on molecular weight, nasal formulation, and individual nasal anatomy.
Related Terms
Frequently asked questions
Why are Semax and Selank given intranasally?+
Intranasal delivery allows these CNS-targeting peptides to potentially bypass the blood-brain barrier via olfactory pathways, and avoids the digestive degradation that would occur with oral administration.
Is intranasal bioavailability as high as subcutaneous?+
Generally not. Intranasal bioavailability varies widely by compound but is typically lower than subcutaneous injection for most peptides.
Can any peptide be given intranasally?+
Only peptides with appropriate molecular properties (small size, stability in nasal conditions) are suitable for intranasal delivery. Most larger research peptides are not well-absorbed via this route.