Mimicking Natural Hormones

These medications work by mimicking the action of glucagon-like peptide-1 (GLP-1), a hormone naturally produced in the gut after eating. GLP-1 plays a vital role in regulating appetite and blood sugar levels.

By binding to GLP-1 receptors in the brain and other organs, these drugs stimulate several physiological processes contributing to weight loss.

Key Mechanisms of Action

Appetite Suppression & Satiety Enhancement

• Delayed Gastric Emptying: GLP-1 receptor agonists slow down the rate at which food leaves the stomach, leading to a prolonged feeling of fullness and reduced appetite. This results in decreased calorie intake, contributing to weight loss.
• Brain Signaling: These medications interact with specific brain areas, including the hypothalamus, which plays a crucial role in appetite regulation. By stimulating these areas, they enhance feelings of satiety and reduce hunger cues, leading to decreased food cravings and overall food consumption.

Glucose Control

• Increased Insulin Secretion: GLP-1 receptor agonists stimulate the pancreas to release more insulin in response to rising blood sugar levels. This helps lower blood glucose levels and improve glycemic control, which can benefit individuals with or at risk of type 2 diabetes.
• Decreased Glucagon Production: They also suppress the release of glucagon, a hormone produced by the pancreas that increases blood sugar levels. This further contributes to improved blood sugar control.

Additional Potential Mechanisms

• Increased Energy Expenditure: GLP-1 receptor agonists may slightly increase energy expenditure, helping to burn more calories.
• Reduced Food Reward: These medications may also affect the brain’s reward system, making food less appealing and decreasing the desire for highly palatable, calorie-dense foods.

How Do Combination Medications like Phentermine-Topiramate Work?

Combination medications like Phentermine-topiramate work through a synergistic mechanism, leveraging the individual effects of each component drug to promote weight loss:

Phentermine

Appetite Suppression: Phentermine is a sympathomimetic amine, structurally similar to amphetamines, that stimulates the release of norepinephrine and dopamine in the brain. This increases feelings of fullness and reduces appetite, leading to decreased calorie intake.

Increased Energy Expenditure: Phentermine may also slightly increase metabolism and energy expenditure, helping to burn more calories.

Topiramate

Appetite Suppression and Satiety Enhancement: Topiramate’s exact mechanism for weight loss is not fully understood. However, it is believed to modulate various neurotransmitters and ion channels in the brain, contributing to reduced appetite and increased feelings of fullness.

Altered Taste Perception: Topiramate can also alter taste perception, making food less appealing and decreasing cravings for sugary or high-calorie foods.

Synergistic Effect

• Combined Action: Combining phentermine and topiramate provides a more comprehensive approach to weight management than either drug alone. Phentermine’s direct appetite suppression is complemented by topiramate’s additional effects on satiety and taste perception.
• Enhanced Efficacy: Studies have shown that the combination leads to more significant weight loss than either the drugs used individually or placebo.
• Reduced Side Effects: The lower doses of each drug in the combination formulation may help minimize specific side effects of higher doses of either drug alone.

Key Points

• Phentermine-topiramate is typically prescribed for individuals with a BMI of 30 or higher or those with a BMI of 27 or higher and at least one weight-related condition (e.g., high blood pressure or type 2 diabetes).
• For optimal results, this medication must be used in conjunction with a reduced-calorie diet and increased physical activity.
• It is important to discuss potential side effects and contraindications with your healthcare provider before starting this medication.

Other Medications

Orlistat (Xenical, Alli)

• Mechanism of Action: Orlistat inhibits lipase, an enzyme that breaks down dietary fat in the intestines. This reduces fat absorption, decreases calorie intake, and promotes weight loss.
• Availability: Available as a prescription medication (Xenical, 120 mg) and over-the-counter (Alli, 60 mg).
• Benefits: When combined with a reduced-calorie diet and exercise, it can lead to modest weight loss. It may also help improve blood sugar control in people with type 2 diabetes.
• Side Effects: Primarily gastrointestinal, including oily stools, diarrhea, gas, and abdominal cramps. These side effects can be reduced by following a low-fat diet.

Bupropion-naltrexone (Contrave)

• Mechanism of Action: Bupropion is an antidepressant that can also reduce appetite, while naltrexone is an opioid antagonist that may decrease food cravings and pleasure associated with eating.
• Benefits: It can aid in weight loss and help maintain weight loss when combined with lifestyle changes.
• Side Effects: May cause nausea, constipation, headache, dizziness, dry mouth, and insomnia. More severe side effects include an increased risk of suicidal thoughts and seizures.

Setmelanotide (Imcivree)

• Mechanism of Action: Setmelanotide targets the melanocortin-4 receptor (MC4R) pathway in the brain, which regulates appetite and energy expenditure. It’s specifically indicated for individuals with rare genetic conditions that affect this pathway, leading to severe obesity.
• Benefits: It can result in significant weight loss and improve hunger control in individuals with these specific genetic disorders.
• Side Effects: May cause nausea, vomiting, diarrhea, abdominal pain, injection site reactions, and sexual dysfunction.

Weight loss medications are not a quick fix or a substitute for healthy lifestyle habits. However, they can be valuable tools to aid in weight loss and improve overall health when used appropriately and under the guidance of a healthcare professional.

Feel free to contact Best Weight Loss Medication with further questions about these or other medications.