Adipotide (FTPP)

Adipotide (FTPP) is one of the more mechanistically dramatic experimental obesity compounds: instead of curbing appetite, it is designed to kill the blood supply feeding white fat. The animal data — in mice and in monkeys — are genuinely striking. But the human story is almost nonexistent: a single four-patient trial that was terminated and never reported results. It is best understood as a preclinical compound that produced impressive results in animals and then stalled before any real human test.

What it is

Adipotide is a synthetic chimeric peptidomimetic, not a hormone or growth factor. Its structure is CKGGRAKDC-GG-D(KLAKLAK)₂ — two functional halves joined by a short linker.

The first half is a homing motif (CKGGRAKDC) that binds prohibitin, a protein enriched on the luminal endothelium of the blood vessels that feed white adipose tissue (WAT). This exact motif was isolated by in vivo phage display in the 2004 Nature Medicine study. The second half is the effector motif, D(KLAKLAK)₂, a pro-apoptotic peptide that disrupts mitochondrial membranes once it is internalized, triggering apoptosis.

Put together, the molecule homes to the vasculature supplying white fat and selectively kills it, causing the fat depot to involute — what the authors called “targeted ablation of adipose tissue.” Crucially, this is not how GLP-1 drugs work: adipotide does not act on appetite or satiety pathways. It is, by design, a cytotoxic, pro-apoptotic agent.

A note on names. In the clinical setting the molecule was called Prohibitin Targeting Peptide 1 (the wording in the official trial title), while Arrowhead’s 2012 press release described it as “formerly known as Prohibitin-TP01.” Both names are real and trace to the same molecule. The abbreviation “PTP-1” is informal shorthand rather than an official designation.

The claims

Adipotide is promoted as a powerful “fat-loss peptide” that melts away white fat by a novel, targeted mechanism — often citing the dramatic animal results as if they translate to people. The honest position is that the animal evidence is real and notable, but there is no confirmed human efficacy or safety data of any kind, and the one human trial that ran was terminated with no results reported.

What the evidence actually shows

The real evidence base is animal and preclinical.

• 2004, obese mice (Nature Medicine). Kolonin, Saha, Chan, Pasqualini, and Arap published the proof of concept: a prohibitin-targeted pro-apoptotic peptide ablated white adipose tissue and reversed obesity in obese mice. This is where the homing motif was first isolated.
• 2011, obese monkeys (Science Translational Medicine). Barnhart and colleagues tested the peptidomimetic in spontaneously obese Old World monkeys (rhesus macaques in the efficacy arm; cynomolgus and baboons in safety/pilot arms). In the fixed-dose efficacy trial, treated monkeys lost from −7.4% to −14.7% of pretreatment body weight by completion (dose-finding animals lost 15.4% and 20.4% over nine weeks), with roughly 10% BMI reduction and improved insulin sensitivity versus controls. The same study surfaced the key safety signal (see below).
• 2012, a published Comment (Science Translational Medicine). Criscione argued that the observed weight loss might partly reflect a direct effect on food intake rather than purely vascular ablation. The original authors published a Response to Comment defending the targeting mechanism. This is a normal scientific debate about why the animals lost weight — not a dispute that they did.

The human evidence is thin to the point of being absent. There was exactly one first-in-human study, NCT01262664 — “A First-in-Man, Phase I Evaluation of A Single Cycle of Prohibitin Targeting Peptide 1 in Patients With Metastatic Prostate Cancer and Obesity,” sponsored by MD Anderson. Per the official ClinicalTrials.gov record, the trial is TERMINATED, with actual enrollment of 4, a start date of May 24, 2012, a completion date of January 2, 2019, “Why stopped” listed as “Terminated per PI’s request,” and no results posted.

A widely repeated claim should be flagged: many secondary peptide-vendor pages assert the trial was “terminated due to nephrotoxicity” or “universal kidney toxicity in all subjects.” That is not in any primary source. The official record gives no efficacy or safety results and states only “per PI’s request,” and there is no peer-reviewed publication of human efficacy or safety outcomes. All human-outcome claims — weight loss and kidney injury alike — should be treated as unverified.

Legal and regulatory status

Adipotide is not approved anywhere. There is no marketed product and no completed efficacy or safety registration trial in humans. It is sold by research-chemical and “peptide” vendors as research-grade (“not for human use”) material, and there is no legal human-therapeutic pathway for it. As of mid-2026, no active clinical development is verifiable.

In sport, adipotide is a prohibitin-targeting pro-apoptotic peptidomimetic — not a peptide hormone, growth factor, or named metabolic modulator — so it is not specifically listed on the WADA Prohibited List, and there is no validated detection method. That does not make it permitted: WADA’s catch-all S0 (non-approved substances) clause can capture experimental, unapproved substances, so absence from a named list does not equal allowed.

For contrast among popular fat/metabolic agents: GLP-1 receptor agonists are not prohibited — semaglutide has been on WADA’s Monitoring Program since 2024, and tirzepatide was added to the 2026 Monitoring Program (monitoring carries no sanction). Meanwhile growth factors, including IGF-1 analogues and mechano growth factor (MGF), are prohibited at all times under S2 (peptide hormones, growth factors, related substances and mimetics).

Safety

The best-documented risk is nephrotoxicity (renal tubular injury). In the obese-monkey study this was clearly dose-dependent — slight-to-moderate serum creatinine elevations at doses above 0.25 mg/kg, plus proteinuria, glucosuria, and histologic renal tubular degeneration and single-cell necrosis at higher doses. The encouraging part is that it was largely reversible: most serum and urine changes reversed within about 28 days of stopping, and BUN was not concurrently elevated, pointing to tubular rather than glomerular injury. This is the most credible safety concern and is plausibly the gating issue, since prohibitin/vascular targeting is not perfectly fat-exclusive.

By design, adipotide is cytotoxic and pro-apoptotic — it kills blood vessels — which makes it inherently higher-risk than appetite-acting agents. Off-target effects on other prohibitin-expressing vasculature are a theoretical concern.

There is no verified human safety data and no long-term data of any kind. It is also not well characterized whether lost fat returns after discontinuation — that is an open unknown rather than a documented finding. And research-grade material carries the usual unregulated-peptide unknowns: purity, endotoxin contamination, and mislabeling. None of this is medical advice.

Bottom line

Adipotide produced striking fat loss in rodents and monkeys through a genuinely novel mechanism — but it never cleared safety into meaningful human testing, and a dose-dependent renal signal is the dominant reason. Framing it as a viable human weight-loss option overstates a single four-patient Phase 1 trial whose results were never reported. The honest grade is animal-stage: impressive biology, no human evidence.

Evidence grade: Animal only.

Sources

• Kolonin et al. Reversal of obesity by targeted ablation of adipose tissue. Nature Medicine 2004;10(6):625-32 (PMID 15133506; DOI 10.1038/nm1048)
• Barnhart et al. A Peptidomimetic Targeting White Fat Causes Weight Loss and Improved Insulin Resistance in Obese Monkeys. Sci Transl Med 2011;3(108):108ra112 (PMID 22072637; DOI 10.1126/scitranslmed.3002621)
• Criscione. Comment on “A Peptidomimetic Targeting White Fat…”. Sci Transl Med 2012 (PMID 22539771; DOI 10.1126/scitranslmed.3003760)
• Authors’ Response to Comment, Sci Transl Med 2012 (DOI 10.1126/scitranslmed.3004103).
• ClinicalTrials.gov, NCT01262664 — MD Anderson; TERMINATED; enrollment 4; no results; “Terminated per PI’s request.”
• Arrowhead Research press release (July 11, 2012) — first-patient dosing, Phase 1, Adipotide
• WADA 2026 Monitoring Program (GLP-1s monitored, not banned) (PDF)
• WADA Prohibited List (S2 covers growth factors incl. IGF-1, MGF)