Adipotide doesn't shrink fat cells. It cuts off their blood supply.
The molecule is a chimeric peptide written as CKGGRAKDC-GG-(D)(KLAKLAK)2. One end is a homing sequence (CKGGRAKDC) that recognizes the blood vessels feeding white fat. The other end is a proapoptotic sequence, (D)(KLAKLAK)2, that disrupts mitochondrial membranes and triggers cell death once it gets inside. Stitched together, the homing peptide delivers the kill signal selectively to the vasculature of white adipose tissue. The fat cells, starved of their blood supply, then die off. It's sometimes catalogued under the name prohibitin-targeting peptide 1 or by its CAS number, 859216-15-2.
Where it came from
The idea traces to a 2004 paper in Nature Medicine by Mikhail Kolonin, Renata Pasqualini, Wadih Arap and colleagues. Using in vivo phage display, they isolated the CKGGRAKDC motif as a peptide that homes specifically to white-fat blood vessels. They found it binds prohibitin, a membrane protein the authors describe as a vascular marker of adipose tissue. When they fused that homing sequence to a proapoptotic peptide and gave it to obese mice, the white fat was resorbed and metabolism normalized. The abstract reports "rapid obesity reversal without detectable adverse effects" (Kolonin et al., *Nature Medicine*, 2004).
What the monkey study showed
The result that got adipotide attention came in 2011, in Science Translational Medicine. Kirstin Barnhart and colleagues tested the peptide in spontaneously obese Old World monkeys. The numbers were striking. At a fixed dose, treated animals lost about 11% of body weight, their BMI dropped roughly 10%, and abdominal circumference fell over 8%. DXA imaging showed a large drop in total body fat. Insulin sensitivity improved measurably (Barnhart et al., *Science Translational Medicine*, 2011).
The same study flagged the catch. The monkeys showed dose-dependent kidney effects, described in the paper as "predictable and reversible changes in renal proximal tubule function." Histology in high-dose animals showed tubular degeneration and single-cell necrosis that resolved during recovery. The kidney signal is consistent with the fact that the peptide is cleared renally and concentrates there.
What happened in humans
Not much that's public. Arrowhead Research licensed the compound and opened a Phase 1 trial around 2012, not in healthy people seeking weight loss but in patients with castrate-resistant prostate cancer who were also obese, on the rationale that white fat can fuel tumor growth. It was given as a daily subcutaneous injection over a 28-day cycle. No peer-reviewed efficacy or safety results from that trial were ever published, and the program was discontinued. There is no completed, published human trial demonstrating that adipotide is safe or effective for weight loss.
Status for buyers
Adipotide is not an approved drug anywhere. It never cleared early clinical development, and the strongest human-relevant safety data, the reversible kidney toxicity, comes from monkeys, not people. Material sold online is a research chemical, labeled research-use-only and not for human consumption. None of this is medical or dosing advice.
If you are evaluating a vendor's adipotide regardless, the questions are the ordinary ones for any obscure peptide. Is there a recent, batch-specific certificate of analysis from an independent lab? Does mass spectrometry confirm the identity and molecular weight of this specific 4.9 kDa chimeric sequence, and does the COA report purity by HPLC? Because demand for adipotide is small and synthesis of a chimeric, cyclized peptide is non-trivial, identity and purity are not safe to assume. Third-party COAs and the independent purity raters this site aggregates are the only objective signal available.
Sources
- Kolonin MG, Saha PK, Chan L, Pasqualini R, Arap W. Reversal of obesity by targeted ablation of adipose tissue. *Nature Medicine*, 2004
- Barnhart KF, et al. A Peptidomimetic Targeting White Fat Causes Weight Loss and Improved Insulin Resistance in Obese Monkeys. *Science Translational Medicine*, 2011
- Prohibitin-targeting peptide 1 — Wikipedia (overview and naming)