From the Guidelines
Metformin does suppress hunger, as evidenced by its effects on decreasing ghrelin levels and increasing insulin and leptin sensitivity, especially with twice-daily dosing. This is supported by a recent study published in JAMA in 2023 1, which highlights metformin's pleiotropic effects, including decreased hunger. The study notes that metformin is associated with approximately 3% weight loss, and approximately 25% to 50% of participants achieve at least 5% weight loss, which can be attributed in part to its appetite-suppressing effects. Some key points to consider when prescribing metformin for its potential hunger-suppressing effects include:
- Doses of metformin greater than 1500 mg are associated with the greatest weight loss, as noted in the study 1
- Twice-daily dosing may be more effective in suppressing hunger due to its impact on ghrelin levels and insulin sensitivity
- Metformin's effects on hunger suppression may vary among patients and should not be considered a guaranteed outcome
- The medication should only be taken as prescribed by a healthcare provider for approved medical conditions, not specifically as an appetite suppressant. As metformin is widely available and inexpensive, it may be a viable option for patients with prediabetes, polycystic ovary syndrome, and overweight/obesity, or to mitigate weight gain due to antipsychotic medication, as mentioned in the study 1.
From the Research
Metformin and Hunger Suppression
- Metformin is known to reduce blood glucose levels and suppress appetite, as reported in a study published in Nature metabolism 2.
- The study found that metformin increases levels of the appetite-suppressing metabolite N-lactoyl phenylalanine (Lac-Phe) in the blood of individuals treated with metformin.
- Another study published in Current obesity reports found that metformin-associated weight loss is due to modulation of hypothalamic appetite regulatory centers, alteration in the gut microbiome, and reversal of consequences of aging 3.
Mechanisms of Action
- Metformin's mechanism of action is based on reducing glucose production in the liver, decreasing insulin resistance, and increasing insulin sensitivity, as reported in a study published in Polish archives of internal medicine 4.
- Metformin has also been shown to have anti-inflammatory and anti-aging effects, which may contribute to its appetite-suppressing properties 5.
Clinical Evidence
- A study published in International journal of clinical practice found that metformin, when combined with rosiglitazone, can achieve additive glucose-lowering efficacy in the treatment of type 2 diabetes, without stimulating insulin secretion and without causing hypoglycaemia 6.
- Overall, the evidence suggests that metformin can suppress hunger and aid in weight loss, particularly in individuals with type 2 diabetes, through its effects on glucose metabolism, appetite regulation, and other mechanisms 2, 3.