Endoscopic gastric injections of botulinum toxin A in 19 obese patients significantly reduced body weight, BMI, and fasting ghrelin levels by slowing stomach emptying, with no severe complications.
Significant ghrelin reduction at 4 weeksAll 19 patients who completed follow-up showed decreased fasting ghrelin levels after gastric botulinum toxin injection, suggesting the treatment modulates hunger signaling beyond just slowing digestion.
What the researchers found
Both treatment groups (200U and 300U BTX-A) showed significant decreases in body weight and BMI (p<0.05). Gastric emptying times increased, particularly at 1 week post-treatment. Fasting ghrelin levels decreased significantly at 4 weeks after treatment. PYY levels decreased, especially at 12 weeks. Triglyceride levels also fell. No severe complications were observed across all 19 patients who completed follow-up.
Why it matters
Obesity treatment options between lifestyle changes and bariatric surgery have historically been limited. This study explored an intermediate approach — using an endoscopic procedure with botulinum toxin (a peptide-based neurotoxin) to modify stomach function without surgery. The discovery that it also reduces ghrelin levels suggests the mechanism goes beyond simply slowing digestion to actually modulating appetite-regulating peptide hormones.
How the study worked
Randomized clinical trial of 20 obese patients (BMI >28 kg/m²) divided into two groups: 200U and 300U of botulinum toxin A. The toxin was injected endoscopically at 20 sites in the gastric wall including the fundus. Body weight, BMI, gastric emptying times, and blood levels of cholesterol, triglycerides, insulin, leptin, motilin, PYY, and ghrelin were measured before treatment and at 1, 4, and 12 weeks after treatment.
What this study cannot tell us
Very small sample size (20 patients, 19 completers) severely limits statistical power and generalizability. There was no placebo/sham endoscopy control group, making it impossible to separate treatment effects from placebo effects. The 12-week follow-up is too short to assess durability of weight loss. The two dose groups were not compared to each other in a meaningful way. No blinding is mentioned. The decrease in PYY (a satiety hormone) after treatment is paradoxical and unexplained.
How to read the evidence
This is a very small randomized trial (n=20) without placebo control or blinding. While it provides hypothesis-generating data, the lack of a sham control group and the tiny sample size mean the results should be interpreted cautiously. The study design is not sufficient to establish efficacy definitively.
When this study was published
Published in 2012, this study predates the current era of GLP-1 agonist-based obesity treatment. While the approach is less prominent now, it contributed to understanding how gastric interventions affect appetite-regulating peptides.
The bigger picture
This study represents an early exploration of endoscopic approaches to obesity that bridge the gap between medication and surgery. While GLP-1 agonists have since emerged as the dominant pharmacological approach, endoscopic procedures like gastric botulinum toxin injection remain of interest for patients who don't respond to or can't access newer medications. The ghrelin-lowering effect also provides insight into how stomach function influences appetite-regulating peptides.
Questions still open
- How long does the weight loss effect of gastric botulinum toxin last beyond 12 weeks, and would repeat treatments be needed?
- Would a placebo-controlled study with sham endoscopy confirm these results or reveal a significant placebo effect?
- How does this approach compare to GLP-1 agonists for weight loss in terms of efficacy, durability, and cost?
Common questions
Can Botox injections in the stomach help with weight loss?
How does stomach Botox reduce appetite?
Read the original research
Treatment of obesity by endoscopic gastric intramural injection of botulinum toxin A: a randomized clinical trial.
Hepato-gastroenterology, 59(118), 2003-7
Citation
Li, Li; Liu, Qing-Sen; Liu, Wen-Hui; Yang, Yun-Sheng; Yan, Dou; Peng, Li-Hua; Li, Lian-Yong; Meng, Jiang-Yun; Wang, Xiang-Dong; Ke, Meng. (2012). Treatment of obesity by endoscopic gastric intramural injection of botulinum toxin A: a randomized clinical trial.. Hepato-gastroenterology, 59(118), 2003-7. https://doi.org/10.5754/hge11755