A quiet analytical research laboratory at night, racks of glass vials along a dim bench.

Cognition and Stress: The Blood-Brain Barrier Is the Problem

The blood-brain barrier excludes almost all large-molecule drugs and most small ones, so cognition products are mainly a delivery challenge. Intranasal routes offer partial access through olfactory and trigeminal pathways, which is why several neuropeptides are studied as nasal sprays. Vegalab works on formulation for lawful actives and describes research compounds without offering them.

The barrier

Brain capillaries have tight junctions and efflux transporters that exclude most molecules above about 400 to 500 Da or with many hydrogen bonds. Nearly all large-molecule drugs and the majority of small ones do not cross in useful amounts. Stress physiology adds a second axis: the hypothalamic-pituitary-adrenal axis and cortisol, which respond to peripheral signals and can be studied without brain penetration. Ingredients such as L-theanine and ashwagandha extract are studied on stress markers, with modest and variable human data.

Neuropeptides and their status

Selank (a tuftsin analog) and Semax (an ACTH 4 to 10 analog) are registered medicines in Russia, given intranasally, and are not approved in the US, EU, UK or Canada. Outside Russia they are unapproved research compounds. Esketamine nasal spray (Spravato) shows that nose-to-brain drug products can win approval, but under a full drug program and restricted distribution. Oxytocin nasal is studied for social cognition with inconsistent results. None of these products has a supplement pathway in the markets Vegalab serves.

Delivery constraints

Nasal delivery has a small volume (about 100 to 150 microliters per nostril), mucociliary clearance that moves material toward the throat within minutes, and peptidase activity in the mucosa. Only a small fraction of a nasal dose reaches brain tissue directly. Oral nootropic ingredients face first-pass metabolism and, for polyphenols, poor solubility. See the intranasal route page and the efflux transporter challenge for design detail. Any product aimed at the brain must show tissue exposure, not assume it.

Key facts

The blood-brain barrier excludes nearly all large-molecule drugs and more than 98% of small-molecule drugs (Pardridge 2005, NeuroRx 2:3)
Intranasal administration can reach the central nervous system via olfactory and trigeminal nerve pathways, bypassing the blood-brain barrier in part (Lochhead and Thorne 2012, Adv Drug Deliv Rev 64:614)
Esketamine nasal spray was FDA approved in 2019 under a restricted distribution program (FDA label, Spravato 2019)
Nasal mucociliary clearance carries deposited material toward the throat within minutes, which limits contact time for intranasal formulations (Illum 2003, J Control Release 87:187)

How our delivery technology applies

Encapsulation cannot make a molecule cross the blood-brain barrier. What it can change is residence and stability at an absorption site: a mucoadhesive outer layer can extend contact time against mucociliary clearance, and inner layers can protect a peptide from nasal peptidases. For oral stress-category ingredients, nano-dispersion addresses solubility. Vegalab measures residence time and stability, and does not claim brain uptake without pharmacokinetic data.

Evaluate an intranasal or oral cognition format in a Vegalab feasibility study.