Adipotide
FTPP, fat-targeted proapoptotic peptide, prohibitin-targeting peptide-1, PTP-1, CKGGRAKDC-GG-D(KLAKLAK)2
Adipotide is not a hormone or a metabolic signal. It is a targeted cell-killing molecule: one half finds the blood vessels feeding white fat, the other half destroys the cells it attaches to. It produced striking weight loss in obese monkeys, then entered a single human trial that enrolled four people and was terminated. It causes kidney damage.
Mechanism
Adipotide works by a mechanism fundamentally unlike every other compound in this class. It is a chimeric peptidomimetic with two functional halves. The first, the cyclic nonapeptide CKGGRAKDC, was identified by phage display screening as a homing sequence that binds prohibitin, a protein that in obese white adipose tissue is aberrantly expressed on the surface of the endothelial cells lining the blood vessels supplying that fat. The second half, D(KLAKLAK)2, is a synthetic proapoptotic domain built from D-amino acids. It is relatively inert outside cells but, once internalised, disrupts mitochondrial membranes and triggers apoptosis.
The strategy is therefore antiangiogenic and cytotoxic rather than metabolic. Adipotide does not act on appetite, satiety, insulin secretion or energy expenditure. It circulates, docks onto prohibitin on white adipose vasculature, is taken up, and kills the endothelial cells. Deprived of blood supply, the surrounding adipocytes undergo apoptosis and the fat depot regresses. The approach was adapted directly from tumour-targeting work in the same laboratory, and the intellectual lineage is oncology, not endocrinology. This matters for how the risks should be understood. Prohibitin is not exclusive to fat vasculature, and any off-target binding delivers a cell-killing payload to whatever tissue it reaches.
What the research shows
The preclinical results were genuinely striking, which is why the compound attracted so much attention. Kolonin and colleagues reported in 2004 that a prohibitin-targeting proapoptotic peptide caused obese mice to lose weight and normalise metabolic parameters. In 2011, Barnhart and colleagues extended this to spontaneously obese rhesus monkeys, reporting substantial weight loss and improved insulin resistance over four weeks of treatment, with the effect apparently specific to white adipose tissue. That paper appeared in Science Translational Medicine and generated worldwide coverage.
The human story ends almost immediately. A single first-in-human phase 1 trial was registered at MD Anderson, evaluating one cycle of prohibitin-targeting peptide-1 in patients with metastatic prostate cancer and obesity. This audit confirmed the registry record directly: enrolment 4, status terminated. No efficacy results were published. No subsequent trial has been registered. There is no published human pharmacokinetic data, no dose-ranging study, and no evidence of any kind that adipotide reduces fat mass in people.
The monkey study also attracted a published methodological critique in the same journal, questioning aspects of the interpretation. More than a decade after the primate results, no company or academic group has taken adipotide forward. In drug development, sustained abandonment after a high-profile positive primate result is itself informative: it usually signals that the toxicity or the development risk was judged prohibitive.
Evidence assessment
Preclinical only
The evidence base is rodent and non-human primate work only, all verified against PubMed; the single registered human trial was confirmed on ClinicalTrials.gov as having enrolled four participants and been terminated with no efficacy results, leaving no human efficacy or safety data whatsoever.
Tiers are applied consistently across the library and re-checked when new trials read out. Read the grading method.
Key studies
Reversal of obesity by targeted ablation of adipose tissue Preclinical only
A prohibitin-targeting proapoptotic peptide ablated white adipose vasculature and reversed obesity in mouse models, establishing the targeted-ablation concept.
A peptidomimetic targeting white fat causes weight loss and improved insulin resistance in obese monkeys Preclinical only
Treatment produced substantial weight loss and improved insulin resistance in obese primates, with dose-dependent renal toxicity observed.
Comment on 'A peptidomimetic targeting white fat causes weight loss and improved insulin resistance in obese monkeys' Preclinical only
Raised methodological and interpretive concerns regarding the obese monkey study.
A First-in-Man, Phase I Evaluation of A Single Cycle of Prohibitin Targeting Peptide 1 in Patients With Metastatic Prostate Cancer and Obesity Limited evidence
The only registered human study of this compound enrolled four participants and was terminated at the principal investigator's request; no efficacy results were published.
Depletion of white adipocyte progenitors induces beige adipocyte differentiation and suppresses obesity development Preclinical only
Depleting white adipocyte progenitors induced beige adipocyte differentiation and suppressed obesity development in mice, extending the mechanistic rationale for adipose-targeted ablation.
Safety
This is the section that matters most and the one that grey-market marketing omits. Adipotide is a cytotoxic agent, and the principal documented toxicity is renal. In the rhesus monkey study, dose-dependent kidney injury was observed, with changes in renal tubular epithelium. The kidney is a plausible target because it is highly vascular and because prohibitin expression is not confined to adipose endothelium, so the proapoptotic payload can be delivered where it is not wanted. Dehydration and reduced food and water intake during treatment compound the renal risk.
Beyond nephrotoxicity, the safety profile in humans is entirely uncharacterised. Four people received it in the only registered trial, which was terminated, and no safety results were published. Nothing is known about immunogenicity, about the consequences of repeated cycles, about effects on other vascular beds, or about whether ablated adipose tissue regenerates or is replaced by fibrosis. A molecule designed to kill cells, with a demonstrated capacity to damage kidneys in primates and effectively no human safety data, is being sold to consumers for cosmetic fat reduction. There is no reasonable framing in which that is a proportionate risk. The 'for research use only' label attached to it functions here as a legal device that permits distribution of an abandoned cytotoxic investigational agent to the public.
Regulatory status
| Jurisdiction | Status |
|---|---|
| United Kingdom | Not licensed by the MHRA for any indication and not in clinical development in the UK. Not an authorised medicine and not an authorised food ingredient. Supply for human use would fall outside the Human Medicines Regulations 2012. |
| United States | Not approved for any indication and not in active development. The only registered human study, NCT01262664, was a phase 1 trial in metastatic prostate cancer and obesity that enrolled four participants and was terminated. It has no legal route to market as a supplement, and material sold to consumers is an unapproved investigational cytotoxic agent. |
| WADA (sport) | Not specifically named on the WADA Prohibited List. As a non-approved pharmacological substance with no approval in any jurisdiction, it falls within class S0 (Non-Approved Substances) and is prohibited at all times for athletes under the Code. |
Questions
Barely. One phase 1 trial was registered, in patients with metastatic prostate cancer and obesity. It enrolled four participants and was terminated at the investigator's request, and no efficacy results were published. There is no other registered human study, no published human pharmacokinetic data, and no evidence that it reduces fat mass in people.
No official explanation was published, but the renal toxicity seen in the primate study is the obvious candidate, alongside the inherent difficulty of justifying a cytotoxic agent for a non-fatal condition. The monkey paper also drew published methodological criticism. Well over a decade of inactivity following a headline primate result is, in drug development terms, a strong signal that the risk-benefit was judged unworkable.
Entirely. GLP-1 agonists are hormone analogues that change appetite and metabolism through receptor signalling, and their effects reverse when you stop. Adipotide kills the blood vessels supplying fat tissue, causing the fat cells to die from lack of blood supply. It is a targeted cytotoxic agent adapted from cancer research. The two do not belong in the same conceptual category despite both being marketed for fat loss.
The honest answer is that it is a cell-killing molecule that caused dose-dependent kidney damage in monkeys and has essentially no human safety data, since only four people have ever received it in a registered trial that was stopped. That combination is not a basis on which anyone can characterise its risk, which is itself the problem. It should not be regarded as a fat-loss option; it is an abandoned investigational cytotoxic agent.