Cognitive & Neuroprotection

Bombesin

Bombesin is a fourteen-amino-acid peptide pulled in 1971 from the skin of European amphibians, and mammals turn out to make close relatives of it. It leads a double life: infused into a person it suppresses appetite, and its receptor is over-produced by some prostate and lung tumours. The second property is what human research is using now — both registered studies on file attach a radioactive label to a bombesin analogue and use positron emission tomography (PET) to find tumours, a diagnostic rather than a treatment. The appetite finding rests on one older infusion experiment, where four nanograms per kilogram per minute cut food intake by 135 grams.

Last updated 12 August 2026

Studied forSatiety research · Gastrointestinal hormone research · Receptor-targeted imaging context

Evidence on file1 human observational study · 1 animal study · 2 citations not yet graded

Strongest sourceNCT05407311: 64Cu-SAR-BBN Positron Emission Tomography: A Phase 2 Study of Participants With PSMA-negative Bi… (human observational study)

Mechanism

Activates bombesin BB1 and BB2 receptors, the mammalian targets of neuromedin B and gastrin-releasing peptide.

Reported effects

What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.

Satiety research
Gastrointestinal hormone research
Receptor-targeted imaging context

Dosing on file unverified

IV: 1.33-4.0 ng/kg/min (food intake studies); Oral MK-5046: 10-160 mg (BRS-3 agonist); RC-3095: 8-96 µg/kg

Carried from a source that labels it unverified, and reproduced with that label attached. A record of what is reported, not a recommendation. No citation on this page establishes it.

Literature on file 4

human observational
NCT05407311: 64Cu-SAR-BBN Positron Emission Tomography: A Phase 2 Study of Participants With PSMA-negative Biochemical Recurrence of Prostate Cancer graded on: a registered clinical study — “clinicaltrials.gov”
animal in vivo
Bombesin-like peptides can function as autocrine growth factors in human small-cell lung cancer (Nature 1985, cited 1031x) graded on: an animal model — read from the indexed abstract — “mice”

Not graded

2 citations whose study design could not be read from the title. Left ungraded rather than guessed at.

not graded
NCT01205321: Open-label, Multi Center PET/CT Study for Investigation of Safety, Tolerability, Biodistribution and Diagnostic Performance of the 68Ga Labeled PET Tracer BAY86-7548 graded on: NCT01205321 is completed and has posted no results - a registration, not a reported outcome — “NCT01205321”
not graded
Isolation and structure of bombesin and alytesin, two analogous active peptides from the skin of the european amphibians (Experientia 1971, cited 782x)

Identity

Space-filling 3D model of Bombesin, carbon grey, nitrogen blue, oxygen red — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

2D chemical structure of Bombesin — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

Molecular weight: 1619.9
Molecular formula: C71H110N24O18S
CAS number: 31362-50-2
PubChem CID: 16201612
InChI key: QXZBMSIDSOZZHK-DOPDSADYSA-N
SMILES: C[C@@H](C(=O)N[C@@H](C(C)C)C(=O)NCC(=O)N[C@@H](CC1=CN=CN1)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCSC)C(=O)N)NC(=O)[C@H](CC2=CNC3=CC=CC=C32)NC(=O)[C@H](CCC(=O)N)NC(=O)[C@H](CC(=O)N)NC(=O)CNC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](CCC(=O)N)NC(=O)[C@@H]4CCC(=O)N4
InChI: InChI=1S/C71H110N24O18S/c1-34(2)24-47(92-62(105)43(14-11-22-79-71(76)77)89-64(107)45(15-18-52(72)96)90-63(106)44-17-20-55(99)85-44)61(104)81-31-56(100)87-51(28-54(74)98)69(112)91-46(16-19-53(73)97)65(108)94-49(26-38-29-80-41-13-10-9-12-40(38)41)66(109)84-37(7)60(103)95-58(36(5)6)70(113)82-32-57(101)86-50(27-39-30-78-33-83-39)68(111)93-48(25-35(3)4)67(110)88-42(59(75)102)21-23-114-8/h9-10,12-13,29-30,33-37,42-51,58,80H,11,14-28,31-32H2,1-8H3,(H2,72,96)(H2,73,97)(H2,74,98)(H2,75,102)(H,78,83)(H,81,104)(H,82,113)(H,84,109)(H,85,99)(H,86,101)(H,87,100)(H,88,110)(H,89,107)(H,90,106)(H,91,112)(H,92,105)(H,93,111)(H,94,108)(H,95,103)(H4,76,77,79)/t37-,42-,43-,44-,45-,46-,47-,48-,49-,50-,51-,58-/m0/s1

Caveat on these identifiers

Match rests on '64Cu-SAR-BBN'; the record never spells out bombesin/GRPR.

Notes unverified prose

IV infusion study: 4 ng/kg/min reduced food intake by 135g; Phase I RC-3095: 8-96 µg/kg in advanced cancer; NCT05407311 (SAR-Bombesin Phase 2); NCT01205321

Not on file 2

1 of the 8 fields we track hold nothing on this record, and each says why. 1 further absence is named below. A blank field is a bug; a named absence is a finding.

amino-acid sequencenothing we hold supplies it
half-lifenothing we hold supplies it

Each field links to every other record missing the same thing. The full ledger holds 765 gaps across 163 records.