Last reviewed 2026-04-22 · How we verify

VI-0521 Top Dose

VI-0521 is a phentermine-based combination product that acts as a sympathomimetic amine to suppress appetite and increase energy expenditure for weight management.

VI-0521 is a phentermine-based combination product that acts as a sympathomimetic amine to suppress appetite and increase energy expenditure for weight management. Used for Obesity management in patients with BMI ≥30 kg/m² or BMI ≥27 kg/m² with weight-related comorbidities.

At a glance

Mechanism of action

VI-0521 Top Dose contains phentermine, which stimulates the release of norepinephrine in the central nervous system, leading to appetite suppression and increased metabolic rate. This mechanism helps reduce caloric intake and promote weight loss when combined with diet and exercise modifications.

Approved indications

• Obesity management in patients with BMI ≥30 kg/m² or BMI ≥27 kg/m² with weight-related comorbidities

Common side effects

• Insomnia
• Dry mouth
• Increased heart rate
• Elevated blood pressure
• Nervousness or anxiety
• Headache

Key clinical trials

• A Study of VI-0521 on Ambulatory Blood Pressure (ABPM) in Overweight or Obese Subjects (PHASE4)
• A Phase IV Safety and Efficacy Study of VI-0521 in Adolescents With Obesity (PHASE4)
• A Pharmacokinetic Study Comparing VI-0521 With Placebo in Obese Adolescents (PHASE4)
• A Study Comparing Multiple Doses of VI-0521 With Placebo and Their Single-agent Constituents for Treatment of Obesity in Adults (PHASE3)
• Study of VI-0521 Compared to Placebo in Treatment of Obesity in Adults (PHASE3)
• Study of VI-0521 Compared to Placebo in Treatment of Diabetes and Obesity in Adults With Obesity-Related Co-Morbid Conditions (PHASE3)

Primary sources

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