DSIP (Delta Sleep Inducing Peptide) — sleep quality research

Dr.SleepRoch said:

Reading about receptor desensitisation and trying to work out which of the effects adapt over time and which do not, because people clearly experience…

Receptor pharmacology relevant to the pharmacology: semaglutide is a GLP-1R agonist with a C-18 fatty acid chain that enables albumin binding (>99%), creating a depot effect with a ~168-hour half-life enabling weekly dosing[1].

Tirzepatide is a dual GIP/GLP-1R agonist with higher GIP affinity (5:1 GIP:GLP-1 potency ratio). The GIP component may enhance beta-cell function and adipocyte lipid metabolism beyond what GLP-1 alone achieves.

For the pharmacology, the pharmacology explains the clinical differences between these agents.

LarryQC_SD said:

Receptor pharmacology relevant to the pharmacology: semaglutide is a GLP-1R agonist with a C-18 fatty acid chain that enables albumin binding (>99%),…

LarryQC_SD has the substance of this right. The condition it depends on is worth stating. The mechanism is more central than most summaries suggest. Receptor agonism in the arcuate nucleus activates POMC neurons and inhibits AgRP/NPY signalling, and the downstream MC4R pathway is the same one disrupted in monogenic obesity — convergent genetic evidence that the target is the right one. Peripherally there is glucose-dependent insulin secretion, glucagon suppression and delayed gastric emptying, but the gastric component largely adapts over months while the central effect persists, which is why the durable effect is appetite rather than fullness.

Dr.SleepRoch said:

Reading about receptor desensitisation and trying to work out which of the effects adapt over time and which do not, because people clearly experience…

This matches mine closely enough to be worth saying so out loud.

From the other side of the consultation, briefly.

Semaglutide structural biology relevant to the pharmacology: semaglutide is a 31-amino acid peptide with 94% homology to native GLP-1(7-36). Three key modifications enable its pharmacokinetic profile:

1. Aib8 substitution: DPP-4 resistance (prevents enzymatic degradation)
2. Arg34 substitution: improved chemical stability
3. C18 fatty diacid at Lys26: albumin binding → long half-life

These three modifications transform a peptide with a 2-minute half-life (native GLP-1) into one with a 168-hour half-life (semaglutide). A masterclass in peptide engineering.