Adipotide (FTPP)

Adipotide (FTPP) has one of the most dramatic ideas behind it of any experimental weight-loss compound. Most diet drugs work on your appetite. This one doesn’t. Instead, it’s built to cut off the blood supply that feeds white fat. The animal results — in both mice and monkeys — are genuinely eye-catching. But the human story is almost a blank page: there was a single trial with just four patients, it was stopped early, and it never reported any results. The fair way to think about adipotide is as an early-stage compound that did impressive things in animals and then stalled before any real test in people.

What it is

Adipotide is a synthetic chimeric peptidomimetic (a lab-made molecule stitched together from two different working pieces, designed to imitate a natural peptide). It is not a hormone or a growth factor. Its structure is CKGGRAKDC-GG-D(KLAKLAK)₂ — two working halves joined by a short linker.

The first half is a homing motif (CKGGRAKDC) — basically a built-in address label. It latches onto prohibitin, a protein that sits in unusually high amounts on the inner lining (the endothelium) of the blood vessels that feed white adipose tissue (WAT) — the body’s main fat-storage tissue. Researchers found this exact address label using a screening technique called in vivo phage display in the 2004 Nature Medicine study. The second half is the effector motif, D(KLAKLAK)₂ — the part that does the damage. Once the molecule gets inside the cell, this piece tears apart the cell’s mitochondria (its energy-producing structures), which sets off apoptosis (programmed cell death — the cell self-destructs).

Put the two halves together and you get a molecule that travels to the blood vessels feeding white fat and selectively kills them, so the fat depot shrinks and collapses in on itself — what the authors called “targeted ablation of adipose tissue.” This is a completely different approach from GLP-1 drugs: adipotide does nothing to hunger or fullness. By design, it is a cytotoxic, pro-apoptotic agent — meaning its whole job is to kill cells.

A quick word on names, because there are several. In the clinical setting it was called Prohibitin Targeting Peptide 1 (the exact 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 point to the same molecule. The abbreviation “PTP-1” is just informal shorthand, not an official name.

The claims

Adipotide is sold as a powerful “fat-loss peptide” that melts away white fat through a clever, targeted mechanism — and the marketing often leans on those dramatic animal results as if they automatically carry over to humans. Here’s the honest version: the animal evidence is real and worth paying attention to, but there is no confirmed proof that it works or is safe in people, and the one human trial that did run was stopped early with no results reported.

What the evidence actually shows

The real evidence is all animal and preclinical (lab and animal work that comes before human trials).

• 2004, obese mice (Nature Medicine). Kolonin, Saha, Chan, Pasqualini, and Arap published the proof of concept: a prohibitin-targeted, cell-killing peptide wiped out white fat and reversed obesity in obese mice. This is where that homing “address label” was first discovered.
• 2011, obese monkeys (Science Translational Medicine). Barnhart and colleagues tested the molecule in naturally obese Old World monkeys (rhesus macaques in the main efficacy group; cynomolgus monkeys and baboons in the safety and pilot groups). In the fixed-dose efficacy trial, treated monkeys lost from −7.4% to −14.7% of their starting body weight by the end (the dose-finding animals lost 15.4% and 20.4% over nine weeks), with roughly 10% BMI reduction and better insulin sensitivity compared with the untreated controls. This same study is also where the main safety warning showed up (more on that below).
• 2012, a published Comment (Science Translational Medicine). Criscione raised the point that some of the weight loss might come from the drug directly cutting food intake, rather than purely from killing fat-feeding blood vessels. The original authors published a Response to Comment defending their targeting mechanism. This is a normal scientific back-and-forth about why the animals lost weight — not an argument over whether they did.

The human evidence is so thin it’s nearly nonexistent. 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. According to the official ClinicalTrials.gov record, the trial is TERMINATED, with actual enrollment of 4 patients, a start date of May 24, 2012, a completion date of January 2, 2019, a “Why stopped” reason listed as “Terminated per PI’s request,” and no results posted.

One widely repeated claim deserves a flag. A lot of secondary peptide-vendor pages state that the trial was “terminated due to nephrotoxicity” (kidney toxicity) or “universal kidney toxicity in all subjects.” None of that appears in any primary source. The official record gives no results at all — neither how well it worked nor whether it was safe — and lists only “per PI’s request” as the reason. There is no peer-reviewed publication of human results either. So every claim about what happened in people — the weight loss and the kidney injury alike — should be treated as unverified.

Legal and regulatory status

Adipotide is not approved anywhere. There is no product on the market, and no completed trial has ever established that it works or is safe in humans. It is sold by research-chemical and “peptide” vendors as research-grade (“not for human use”) material, and there is no legal route to use it as a human medicine. As of mid-2026, there is no verifiable active clinical development.

In sports, adipotide is a prohibitin-targeting, cell-killing peptidomimetic — not a peptide hormone, a growth factor, or any named metabolic agent — so it is not specifically named on the WADA Prohibited List (the World Anti-Doping Agency’s list of banned substances), and there is no validated test to detect it. But that does not make it allowed: WADA’s catch-all S0 clause (non-approved substances) can sweep in experimental, unapproved substances, so not being on a named list does not mean it’s permitted.

For some context on how other popular fat and metabolic drugs are treated: GLP-1 receptor agonists are not banned — semaglutide has been on WADA’s Monitoring Program since 2024, and tirzepatide was added to the 2026 Monitoring Program (being monitored carries no penalty). On the other hand, growth factors — including IGF-1 analogues and mechano growth factor (MGF) — are banned at all times under S2 (the category covering peptide hormones, growth factors, and related substances and look-alikes).

Safety

The best-documented risk is nephrotoxicity — kidney damage, specifically injury to the renal tubules (the tiny tubes in the kidney that filter and reabsorb fluid). In the obese-monkey study, this was clearly dose-dependent (the higher the dose, the worse it got): slight-to-moderate rises in serum creatinine (a blood marker of kidney strain) at doses above 0.25 mg/kg, plus protein and glucose leaking into the urine, and — at higher doses — visible tissue damage described as renal tubular degeneration and single-cell necrosis (individual kidney cells dying). The encouraging part is that the damage was largely reversible: most blood and urine changes went back to normal within about 28 days of stopping, and BUN (another kidney blood marker) didn’t rise at the same time, which suggests the harm was to the tubules rather than the glomeruli (the kidney’s filtering units). This is the most credible safety concern, and it’s probably the make-or-break problem, since the prohibitin/vessel targeting isn’t perfectly limited to fat alone.

By design, adipotide is cytotoxic and pro-apoptotic — it kills blood vessels — which makes it inherently riskier than drugs that simply work on appetite. There’s also a theoretical worry that it could hit blood vessels elsewhere in the body that also carry prohibitin, not just the ones feeding fat.

There is no verified human safety data and no long-term data of any kind. It’s also not clear whether the lost fat comes back once you stop — that’s an open question, not something that has been documented either way. And as with any research-grade material, you inherit all the usual unknowns of an unregulated peptide: how pure it actually is, whether it’s contaminated with endotoxins (bacterial byproducts that can cause fever and worse), and whether it’s even labeled correctly. None of this is medical advice.

Bottom line

Adipotide produced striking fat loss in rodents and monkeys through a genuinely new mechanism — but it never cleared safety into meaningful human testing, and a dose-dependent kidney signal is the biggest reason why. Treating it as a real human weight-loss option reads far too much into a single four-patient Phase 1 trial that never reported its results. The honest grade is animal-stage: impressive biology, no human evidence.

Evidence grade: 3/10 · 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)