PEP-SMG-1 vs PEP-TZP-2: single or dual incretin agonism?
PEP-SMG-1 is a GLP-1 receptor agonist and the most-studied compound in the incretin class. PEP-TZP-2 adds GIP receptor activity. Choose PEP-SMG-1 as the reference for any GLP-1 question; choose PEP-TZP-2 when the GIP pathway or the interaction between the two receptors is the question. Both are lot-tested and sold for laboratory research only.
| PEP-SMG-1 | PEP-TZP-2 | |
|---|---|---|
| Receptors | GLP-1 | GIP, GLP-1 |
| Length | 31 amino acids | 39 amino acids |
| Backbone | Human GLP-1 analogue | GIP-derived |
| Half-life basis | C18 fatty diacid, about 7 days | C20 fatty diacid, about 5 days |
| Distinguishing property | Largest published dataset in the class | GIP receptor bias |
| Typical research use | GLP-1 reference compound; cardiovascular, renal, CNS models | Dual-incretin signalling; comparison against GLP-1-only |
| Key clinical context | STEP 1, NEJM 2021; SELECT, NEJM 2023 | SURMOUNT-1, NEJM 2022 |
| Current lot purity | 99.75% (SEMA5-0803) | 99.80% (TIR10-0803) |
| Vial | 5 mg, $95 | 10 mg, $120 |
Why start with PEP-SMG-1?
Because everything else in the class is measured against it. The GLP-1 receptor is expressed in pancreas, gut, brain, heart and kidney, and PEP-SMG-1's literature covers all of them, so a PEP-SMG-1 arm gives a study a reference point that reviewers recognise.
What does GIP add, and is it agonism that matters?
GIP receptor activation potentiates insulin release and acts on adipose tissue and central appetite circuits. Whether PEP-TZP-2's effect comes from GIP agonism, from its particular receptor bias, or from something else is an open research question, and it is the reason PEP-TZP-2 is worth studying rather than regarding as a stronger PEP-SMG-1.
Which vial size?
PEP-SMG-1 is supplied at 5 mg and PEP-TZP-2 at 10 mg, reflecting the concentrations typical in their respective assays. The Metabolic trio bundle adds PEP-RTA-3 for a three-arm design.
What do the current certificates show?
Pharmacology decides which compound answers the question; the certificate decides what is actually in the vial. These are the current lots for each, read from the certificate library:
| Compound | Lot | Identity | Purity | Content | Issued |
|---|---|---|---|---|---|
| PEP-SMG-1 | SEMA5-0803 | LC-MS/MS | 99.75% | 5.19 mg vs 5 mg label | Aug 17, 2026 |
| PEP-TZP-2 | TIR10-0803 | LC-MS/MS | 99.80% | 10.18 mg vs 10 mg label | Aug 17, 2026 |
Purity on both lines is area percent by RP-HPLC at 214 nm, which the area-percent post explains is a ratio of peak areas and not a weight, so the two figures are comparable only because the method is the same. Content is the measured mass against the label, and the lot-to-lot post is the case for using it rather than the label in any calculation. All 114 certificates read together are in the certificate dataset.
Common questions
What does adding GIP change?
PEP-TZP-2 engages GIP alongside GLP-1, so any difference against PEP-SMG-1 in the same model is attributable to GIP receptor activity. That is the comparison most study designs are built to make.
Do they reconstitute the same way?
Both are acylated and dissolve slowly. Swirl rather than shake and allow time; the reconstitution guide covers the volumes.
Where to go next
For laboratory research use only. Clinical trial results are cited as context and do not describe use of the material sold here.