From the Guidelines

GLP-1 induces long-term weight loss primarily through central appetite suppression.

GLP-1 receptor agonists, such as semaglutide and liraglutide, mimic the effects of GLP-1, which acts on the hypothalamus to suppress appetite and increase feelings of satiety 1.
The effects of GLP-1 receptor agonists on gastric emptying vary, with some studies showing delayed gastric emptying, particularly with short-acting agents like liraglutide, while others show no significant delay with long-acting agents like semaglutide 1.
However, the primary mechanism of weight loss with GLP-1 receptor agonists is thought to be through central appetite suppression, rather than delayed gastric emptying 1.

The STEP trials demonstrated significant weight loss with semaglutide, with a mean weight loss of 14.9% at 68 weeks, compared to 2.4% with placebo 1.
A systematic review of randomized trials evaluating the effects of GLP-1 receptor agonists on gastric emptying found that the effects of these agents on gastric emptying are variable and may be influenced by the frequency and duration of exposure 1.
The AGA clinical practice guideline on pharmacological interventions for adults with obesity recommends the use of semaglutide for weight loss, citing its efficacy and safety profile 1.

GLP-1 receptor agonists, such as semaglutide and liraglutide, are effective for weight loss in adults with obesity, with significant reductions in body weight and improvements in weight-related comorbidities 1.
The primary mechanism of weight loss with GLP-1 receptor agonists is thought to be through central appetite suppression, rather than delayed gastric emptying 1.
The effects of GLP-1 receptor agonists on gastric emptying are variable and may be influenced by the frequency and duration of exposure 1.

From the Research

GLP-1 induces weight loss through multiple mechanisms, including reduced gastric emptying and central appetite suppression 2, 3, 4, 5, 6
The hormone delays gastric emptying and gut motility in humans, leading to reduced food intake and weight loss 2, 4, 5
GLP-1 also affects the central regulation of feeding, inhibiting food intake independent of the presence of food in the stomach or gastric emptying 2, 5, 6
The synergistic actions of GLP-1 in the gut and brain, acting on both central and peripheral receptors, are responsible for its effects on satiety and weight loss 2, 6

GLP-1 has been shown to reduce appetite and food intake, leading to moderate weight loss in clinical trials 3, 6
The hormone's effects on appetite and weight are thought to be mediated by its actions on the central nervous system, including the hypothalamus 2, 5, 6
GLP-1 receptor agonists have been developed as a treatment for type 2 diabetes and obesity, and have been shown to be effective in reducing weight and improving glycemic control 3, 6

GLP-1 has been shown to decelerate gastric emptying, leading to reduced food intake and weight loss 3, 4, 5
The hormone's effects on gastric emptying are thought to be mediated by its actions on the gastrointestinal tract, including the inhibition of gastric motility and secretion 4, 5
The reduction in gastric emptying caused by GLP-1 may contribute to its effects on satiety and weight loss 2, 4, 5