Adipotide (FTPP): the complete research guide.

Adipotide is a synthetic peptide designed to kill fat tissue by cutting off its blood supply. In 2011 it shrank obese monkeys by 11% body weight in four weeks. Then the Phase I human trial found kidney damage, and the story stopped there.

What adipotide actually is

Adipotide is a synthetic peptide stitched together from two parts. The first part is a homing sequence, CKGGRAKDC. It binds a protein called prohibitin. That protein sits on the surface of blood vessels feeding white fat tissue. The second part is a killer domain. It disrupts mitochondrial membranes inside cells.

The Pasqualini and Arap groups developed the full molecule. Their base was MD Anderson, now Rutgers Cancer Institute. The design borrows directly from anti-cancer drugs. Find a vascular bed. Find a peptide that homes to it. Attach something cytotoxic. Kolonin and colleagues laid that out in 2004.

The category matters. Adipotide is not a metabolic drug. It is not an appetite suppressant. It is a cytotoxic agent. It ablates the blood supply to fat tissue. Its closest conceptual neighbor is anti-cancer therapy, not semaglutide.

How it was supposed to work

Three steps. First, the homing sequence binds prohibitin. The target is the endothelial cells of fat-tissue blood vessels. Prohibitin usually lives inside mitochondria. But on adipose endothelium it pops up on the cell surface. That is what gives adipotide its tissue selectivity.

Second, the peptide gets internalized. Third, the killer domain inserts into the mitochondrial inner membrane. The membrane collapses. The cell then dies by apoptosis, meaning programmed cell death. Endothelial cells die. The microvasculature dies with them. And the fat tissue they fed shrinks. That is per Barnhart and colleagues in 2011.

Adipotide takes a fundamentally different approach. Incretin drugs like semaglutide work upstream of fat mass, through satiety signals. Adipotide targets the fat mass directly by ablating its blood supply. That's conceptually closer to anti-cancer therapy than to metabolic medicine.

The 2011 monkey data, in plain terms

The headline study came from Barnhart and colleagues in 2011, in Science Translational Medicine. They treated naturally obese rhesus macaques with adipotide for four weeks, and here is what they reported.

• ~11% body-weight reduction at four weeks, mostly from white fat on imaging.
• Smaller waist measurements and less visceral fat on CT.
• Better insulin sensitivity (lower fasting insulin, better glucose tolerance).
• Weight stabilized or modestly regained after dosing stopped. That fits the mechanism, since there's no chronic satiety effect.
• Renal toxicity: elevated BUN and creatinine in treated animals. The authors flagged it as dose-limiting.

The 2011 media cycle focused on the body-weight reduction. The kidney findings were in the paper, but they got far less attention in the press. We think that asymmetry is why a grey market for adipotide still exists in 2026.

The Phase I human trial, and where the kidney signal came from

The Phase I trial was registered as NCT01262664 and enrolled obese prostate cancer patients. The developers picked that population because the cytotoxic mechanism overlapped with their oncology work.

The Phase I outcome that matters is that there isn't one. Actual enrollment was four against a planned five dose levels, the registry lists the study as terminated at the investigator's request, and no results were posted. The BUN and creatinine elevations on record come from the primate work, not from people. Adipotide leaves the body through the kidneys, and the killer domain has potential for off-target damage to kidney tissue.

Was the renal signal dose-titratable in people? We'll never know. Phase II never happened, and no results from NCT01262664 have been posted or published. That's the central honest fact about adipotide in 2026: the primate kidney signal is documented, the human trial stopped after four participants, and the stated reason was the investigator's request rather than a published safety finding.

Why the field moved on

Two things happened between 2011 and 2026 that closed adipotide's clinical case.

First, the kidney signal didn't go away. The original developers had every academic and commercial reason to advance the program. They didn't. Fifteen years of silence on a flagship clinical asset is itself a data point you should weigh.

Second, the incretin class arrived. Semaglutide hit ~15% mean body-weight reduction in STEP and earned FDA approval as Wegovy in 2021. Tirzepatide hit 22.5% in SURMOUNT-1 and approval as Zepbound in 2023. Retatrutide hit 24.2% at the highest dose in the 2023 Phase II NEJM trial, with Phase III TRIUMPH still running.

Adipotide's framing was “body-weight reduction without appetite suppression.” In 2011 that was a genuinely differentiated mechanism, against what the incretin class had shown.

By 2026, tirzepatide and retatrutide had produced 22–24% mean body-weight reductions in Phase III trials. That made the adipotide framing redundant on efficacy grounds, with the kidney signal still unresolved.

The published literature reflects the move. The two indexed papers from 2020 to 2026 don't treat adipotide as an obesity drug at all. They repurpose the homing sequence as a delivery vehicle.

Hong and Kim in 2022 attached heme oxygenase-1 inducers for fatty liver disease. Hu and colleagues in 2020 used it as an MRI imaging probe. The homing sequence still has value. The cytotoxic version doesn't.

Risks and the grey-market reality

• Renal toxicity in both primate and Phase I human dosing. Elevated BUN and creatinine in both data sets. This is the signature safety finding of the molecule.
• Cytotoxic mechanism with no chronic dosing data. Repeated cycles of fat-vessel ablation and regrowth have no long-term human safety record. The closest analog is anti-cancer therapy, where patient timelines are shorter than the obesity treatment horizon.
• Off-target potential. Prohibitin shows up in many tissues. The homing sequence isn't perfectly selective for fat vasculature. Effects on heart, liver, or kidney blood vessels are theoretically possible.
• Manufacturing complexity creates identity risk. Real adipotide needs correct disulfide bonds in the cyclic homing domain plus correct D-amino-acid composition in the killer domain. Grey-market vendors can't reliably demonstrate that.
• Vendor marketing leans on a 15-year-old story. Product pages reference the 2011 monkey results while skipping the kidney signal and the missing Phase II/III data.
• Evidence comparison. The preclinical data supporting adipotide predates the modern incretin class by over a decade, and the documented kidney signal accompanies it. The incretin class has since demonstrated superior Phase III evidence and documented human safety profiles.

Regulatory and legal status

• FDA: Not approved for any indication. No active IND has produced peer-reviewed Phase II/III obesity data.
• EMA: Not approved.
• WADA: Not explicitly listed by name. The anti-vasculature mechanism doesn't map cleanly onto standard performance-enhancement categories.
• Research compound status: Sale as a research reference compound labeled for laboratory use is permitted in the US. Marketing it as an obesity therapeutic crosses into FDA jurisdiction.

What adipotide should and shouldn't be used for

If you want a defensible scientific use for the homing sequence in 2026, it's as a delivery vehicle for safer payloads. That's what the recent literature shows happening. The targeting peptide keeps its scientific value, and the cytotoxic killer domain gets left behind with its kidney baggage.

In our reading, the original framing of adipotide as an obesity drug doesn't survive scrutiny. The Phase I kidney signal closed that door. The incretin class's arrival made reopening it commercially indefensible.

Frequently asked questions

What is adipotide?

Adipotide, also called FTPP, is a synthetic peptide that pairs a fat-vessel homing sequence with a cytotoxic killer domain. It targets the blood supply of white fat tissue and triggers apoptosis. It's a cytotoxic anti-vasculature agent, not a metabolic drug, and it's not FDA-approved.

Did adipotide cause kidney toxicity in humans?

No published human data says so. The Phase I trial, NCT01262664, enrolled four participants, terminated at the investigator's request and posted no results. The renal signal that is documented comes from the 2011 monkey study. The killer domain has off-target potential on kidney tissue, and the drug is excreted renally. That signal is the main reason clinical development has been frozen for fifteen years.

Why is adipotide still sold if it failed Phase I?

The 2011 monkey body-weight-reduction story got heavy media coverage and created lasting consumer demand. Grey-market vendors lean on that 15-year-old story, and skip the primate kidney signal when they sell it to you. It's the textbook pattern of a peptide whose press cycle outlasted the science that disconfirmed it. A vendor that omits a known safety signal is failing one of the checks worth walking away over.

How does it compare to incretin drugs?

Different drug classes entirely. Tirzepatide and retatrutide are incretin drugs with multiple Phase III trials, documented safety profiles, and 22–24% mean body-weight reduction. Adipotide is a cytotoxic agent with no Phase II/III trials and a kidney signal documented in primates. We can't find a clinical scenario in 2026 that favors adipotide over an FDA-approved incretin.

Is adipotide FDA-approved?

No. One Phase I trial, NCT01262664, was registered, and it produced no peer-reviewed efficacy publications. No Phase II or III trials exist. You can sell it legally as a research reference compound labeled for lab use. Marketing it for human obesity treatment is not permitted.

Has adipotide been investigated in humans for the obesity indication?

One registered Phase I trial, NCT01262664, enrolled obese prostate cancer patients. No peer-reviewed Phase II or III efficacy results have been published. The primate work documented a renal toxicity signal consistent with the primate data.

Development hasn't advanced in over a decade. The incretin class has since accumulated multiple Phase III trials and documented human safety data that the adipotide literature simply doesn't have.