90-day randomized trial: oral Pep19 10 mg shifted fat distribution and improved insulin sensitivity markers without weight change
In a randomized, double-blind, placebo-controlled 90-day trial in 56 adults with obesity in Brazil, published in iScience, oral Pep19 at 10 mg daily reduced the android-to-gynoid fat ratio and abdominal skinfold thickness and lowered HbA1c and HOMA-IR without significant weight change; fasting glucose was unchanged.
iScience has published a randomized, double-blind, placebo-controlled trial of Pep19, an oral intracellular peptide (sequence DIIADDEPLT) characterized in preclinical work as a CB1 receptor inverse agonist, in adults with obesity. The paper appeared online September 8, 2026 (DOI 10.1016/j.isci.2026.117471) and in the journal's October 16, 2026 issue. Sixty adults with BMI 30-39.9 kg/m2 were enrolled and randomized; 56 completed the 90-day intervention and were included in the final analysis.
Participants received oral placebo or Pep19 at 5 mg or 10 mg daily for 90 days. Regional fat distribution was assessed by imaging (android-to-gynoid fat ratio) and abdominal skinfold thickness, alongside glycated hemoglobin (HbA1c), HOMA-IR and fasting glucose. The trial was approved by the Ethics Committee of Centro Universitario FMABC (CAAE: 84285324.20000.0082) and registered at the Brazilian Registry of Clinical Trials (RBR-10zchcdk).
At 10 mg, Pep19 reduced the android-to-gynoid fat ratio and decreased abdominal skinfold thickness without affecting body weight, caloric intake or physical activity. HbA1c and HOMA-IR were significantly reduced while fasting glucose was unchanged, which the authors interpret as improved insulin sensitivity independent of weight loss.
Limits: the trial was small and single-country, ran only 90 days, and analyzed completers; Pep19 is a supplement ingredient, not an approved drug, and the generally-recognized-as-safe status cited in the paper rests on the self-affirmation framework of 21 C.F.R. 170.30, which is not FDA approval. Study procedures were funded by Fundacao do ABC, while the Pep19 capsules were manufactured by the product's developer. The authors call for larger and longer-term studies. This brief reports trial findings and is not a treatment recommendation or an endorsement of any product.