Metabolic & Weight Management

Ghrelin

Ghrelin is the signal an empty stomach sends to make you hungry, the counterweight to every fullness hormone the obesity drugs imitate. The human experiment on file is direct and blunt: nine volunteers were infused with ghrelin or saline under double-blind crossover conditions and then shown a free-choice buffet, and every one of them ate more on ghrelin, by 28 percent on average. It is also a powerful trigger for growth hormone release, which is why it appears in research on frailty and appetite loss as well as in obesity. Nobody sells ghrelin as a treatment, and the rest of the human record is infusion work and registered studies, including dose-finding in frail older adults and studies of alcohol craving.

Last updated 12 August 2026

Studied forAppetite regulation research · Growth hormone research · Energy balance context

Evidence on file5 human observational studies · 1 animal study · 2 in-vitro studies · 1 citation not yet graded

Strongest sourceNCT00520884: A Pilot Study of Ghrelin in Healthy and Frail Older Women (human observational study)

Mechanism

Acylated ghrelin activates the GHS-R1a receptor in the pituitary and hypothalamus, stimulating growth hormone release and hunger signalling.

Reported effects

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

Appetite regulation research
Growth hormone research
Energy balance context

Dosing on file unverified

IV bolus: 1-5 µg/kg; IV infusion: 0.1 µg/kg/min or 30 pmol/kg/min

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.

Half-life, storage & sport

Elimination half-life: ~11 min (human, IV) — study. Journal of cachexia, sarcopenia and muscle 2026.

The half-life on file is 11 min, measured intravenously. No dosing schedule could be read from this record, so the curve below is one dose drawn from the moment it is given. Nothing here says how often it is repeated.

One dose. 55 min of decay, normalised to its own peak.

The rise is not modelled and the axis is not a blood level. No absorption rate constant and no volume of distribution are on file, so each dose appears at full height the instant it is given, and the axis is percent of this compound's own peak.

Literature on file 11

review or editorial
Targeting the leptin-ghrelin axis for obesity management: Mechanistic insights and therapeutic approaches. graded on: indexed as "Review" - secondary literature, not a study — “Review”
review or editorial
The Ghrelin-LEAP2 System in Obesity and Diabetes: Pathophysiological Roles and Therapeutic Potential. graded on: indexed as "review-article" - secondary literature, not a study — “review-article”
in vitro
Alcohol Exposure Alters the Ghrelin System: In Vitro Mechanistic Insights Into Impaired Glucose Sensing and Enhanced Ghrelin Secretion. graded on: an in-vitro system — “In Vitro”
animal in vivo
Activation of GHSRs Facilitates the Excitability of Dentate Gyrus Granule Cells and Short-Term Spatial Memory via Multiple Ionic and Signaling Mechanisms. graded on: an animal model — read from the indexed abstract — “rats”
in vitro
Preliminary investigation of ghrelin in horses and ponies: receptor expression and associations with prandial state, morphometry and signalment. graded on: an in-vitro system — read from the indexed abstract — “assay”
human observational
NCT00520884: A Pilot Study of Ghrelin in Healthy and Frail Older Women graded on: a registered clinical study — “clinicaltrials.gov”
human observational
NCT01605435: Ghrelin In Frail Elderly Subcutaneous Dose Finding Study graded on: a registered clinical study — “clinicaltrials.gov”
human observational
NCT01779024: Effects of Ghrelin on Alcohol Administration in Non-Treatment Seeking Heavy Drinkers graded on: a registered clinical study — “clinicaltrials.gov”
human observational
NCT01833078: Ghrelin in Frail Elderly Subcutaneous Repeated Dose Study graded on: a registered clinical study — “clinicaltrials.gov”
human observational
NCT01898611: Ghrelin Plus Strength Training in Frail Elderly Study graded on: a registered clinical study — “clinicaltrials.gov”

Not graded

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

not graded
Ghrelin (2013, cited 2x)

Identity

Space-filling 3D model of Ghrelin, 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 Ghrelin — 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: 3370.9
Molecular formula: C149H249N47O42
CAS number: 304853-26-7
PubChem CID: 16133832
InChI key: GNKDKYIHGQKHHM-RJKLHVOGSA-N
SMILES: CCCCCCCC(=O)OC[C@@H](C(=O)N[C@@H](CC1=CC=CC=C1)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CO)C(=O)N2CCC[C@H]2C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CC3=CNC=N3)C(=O)N[C@@H](CCC(=O)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](C(C)C)C(=O)N[C@@H](CCC(=O)N)C(=O)N[C@@H](CCC(=O)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N4CCC[C@H]4C(=O)N5CCC[C@H]5C(=O)N[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCC(=O)N)C(=O)N6CCC[C@H]6C(=O)N[C@@H](CCCNC(=N)N)C(=O)O)NC(=O)[C@H](CO)NC(=O)CN
InChI: InChI=1S/C149H249N47O42/c1-9-10-11-12-16-45-118(209)238-78-106(191-135(225)103(75-197)171-115(204)73-154)137(227)187-101(71-84-32-14-13-15-33-84)133(223)186-100(70-81(4)5)132(222)190-105(77-199)144(234)194-66-29-42-108(194)139(229)180-95(51-57-117(207)208)128(218)188-102(72-85-74-165-79-169-85)134(224)179-92(47-53-112(156)201)126(216)175-90(39-26-63-167-148(161)162)130(220)192-119(82(6)7)141(231)181-93(48-54-113(157)202)127(217)177-91(46-52-111(155)200)125(215)174-89(38-25-62-166-147(159)160)122(212)173-87(35-18-22-59-151)121(211)178-94(50-56-116(205)206)129(219)189-104(76-198)136(226)176-88(36-19-23-60-152)123(213)182-96(37-20-24-61-153)142(232)196-68-31-44-110(196)145(235)195-67-30-41-107(195)138(228)170-83(8)120(210)172-86(34-17-21-58-150)124(214)185-99(69-80(2)3)131(221)183-97(49-55-114(158)203)143(233)193-65-28-43-109(193)140(230)184-98(146(236)237)40-27-64-168-149(163)164/h13-15,32-33,74,79-83,86-110,119,197-199H,9-12,16-31,34-73,75-78,150-154H2,1-8H3,(H2,155,200)(H2,156,201)(H2,157,202)(H2,158,203)(H,165,169)(H,170,228)(H,171,204)(H,172,210)(H,173,212)(H,174,215)(H,175,216)(H,176,226)(H,177,217)(H,178,211)(H,179,224)(H,180,229)(H,181,231)(H,182,213)(H,183,221)(H,184,230)(H,185,214)(H,186,223)(H,187,227)(H,188,218)(H,189,219)(H,190,222)(H,191,225)(H,192,220)(H,205,206)(H,207,208)(H,236,237)(H4,159,160,166)(H4,161,162,167)(H4,163,164,168)/t83-,86-,87-,88-,89-,90-,91-,92-,93-,94-,95-,96-,97-,98-,99-,100-,101-,102-,103-,104-,105-,106-,107-,108-,109-,110-,119-/m0/s1

Notes unverified prose

Human IV infusion studies

Not on file 1

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

amino-acid sequencenothing we hold supplies it

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

Listed prices 2

What 2 shops we track listed for Ghrelin, read from their own public catalogues on 2026-09-14. We take no commission on these and they are not ranked by any payment — how vendors are scored.

Compare prices2 listings from 2 shops

Listed in USD
Vendor	Size	Price	Per mg
PureRawz ships worldwide	2 mg	$75.96 USD	$37.98/mg
Behemoth Labz	2 mg	$80.26 USD	$40.13/mg

Prices are the vendor's own listing, reproduced with the date we read it — never converted between currencies, and compared per milligram only where the vendor states the vial size.

At a glance

Strongest rung: human observational
Citations: 11
Regulatory: Human research reported (unverified)
Route: Intravenous
Declared gaps: 1

Running this

Growth hormone axis

How the class is run, with the source of every schedule beside it.

Citations by rung

Strongest wins, never an average.