A new study published in the Journal of Diabetes Obesity and Metabolism found that, Orlistat mouth rinse may be an effective alternative in lowering calorie intake while minimizing undesirable side effects in Obese people.
Orlistat belongs to a family of medications known as anti-obesity treatments, which are used to treat obesity and greatly help in weight loss. Orlistat should always be used in conjunction with a low-calorie diet and frequent physical activity. Obesity is a prevalent disorder characterized by excess body fat, which raises the risk of numerous health issues such as diabetes, high blood pressure, some malignancies, and heart disease. As a result, the team led by Stefany Primeaux undertook this study to completely explore the effects of an orlistat mouth rinse on the consumption of a high-fat meal.

In this double-blind, balanced order, crossover study, the participants (n = 10, body mass index 25-30 kg/m2) were randomized to consume placebo or orlistat (24 mg/mL) prior to a high-fat meal. Following placebo delivery, participants were separated into low-fat and high-fat consumers based on the number of calories ingested from fat.
The key findings of this study were:

The orlistat mouth rinse reduced total and fat calories taken during the high-fat meal in high-fat consumers but had no effect on low-fat consumers (P 0.05).
Orlistat reduces long-chain fatty acid (LCFA) absorption by blocking the lipases that break down lipids. Orlistat mouth rinse reduced fat intake in high-fat consumers, indicating that orlistat prevented LCFA detection from the high-fat test meal. Orlistat delivered orally is expected to reduce the risk of oil incontinence and also enhance weight loss in people who prefer fat based food.
Reference:
Primeaux, S. D., Dubin, R., & Greenway, F. L. (2023). Orlistat mouth rinse: Using the tongue to deliver antiobesity medication in a double‐blind randomized crossover pilot trial. In Diabetes, Obesity and Metabolism. Wiley. https://doi.org/10.1111/dom.15101