Does BPC-157 actually cross the BBB?
47 posts
Seeing claims in various places that BPC has CNS effects — anxiolytic, neuroprotective, serotonergic modulation. The rodent CNS work does exist. But the blood-brain barrier permeability of a 15aa peptide is, at minimum, a real question.
Is there actual data on BBB crossing or is everyone extrapolating 'it had CNS effects in rats when injected IP, therefore it crossed the BBB'? Those are different claims. A peripheral anti-inflammatory effect could produce CNS changes without the molecule ever entering the brain.
Anyone have a better read on this than I do?
- Semax · 600 mcg · AM intranasal · intranasal
- Selank · 250 mcg · as needed · intranasal
5 Replies
122 posts
Short answer: the direct BBB crossing evidence is weak. Most of the CNS data can be explained by peripheral vagal/immune/gut-brain axis signaling rather than direct central action. 'Affects the brain' and 'gets into the brain' are different. Most BPC neuro-claims would survive if it never crossed the BBB at all.
117 posts
Agreed. The community tendency is 'CNS effect observed = molecule must be central.' That's not how vagal afferents work. BPC's anti-inflammatory signaling from the periphery is a plausible mechanism for a lot of the 'mood' reports without any BBB crossing required.
25 posts
The fact that the 'BPC for anxiety' crowd always stacks it with something is a tell. Isolate the variable, then we can talk about CNS effects.
47 posts
So the consensus is 'CNS effects real, BBB crossing probably not the mechanism.' That actually matches my read. Thanks for the sanity check.
- Semax · 600 mcg · AM intranasal · intranasal
- Selank · 250 mcg · as needed · intranasal
38 posts
Yeah this thread nailed it. The BBB crossing claim is basically cargo cult science at this point. People ran it in rats, saw some behavioral output, and decided it must be central without ever actually checking. The peripheral anti-inflammatory angle explains like 90% of what people report anyway. Vagal signaling is a hell of a drug and way more plausible than a 15aa peptide just waltzing through the barrier.