From the FDA Drug Label
Phentermine is not recommended for use in patients 16 years of age and under. Pediatric use: Safety and effectiveness not established.
The use of phentermine in a 9-year-old patient is not recommended because the safety and effectiveness of the drug have not been established in pediatric patients. 1 1
From the Research
Phentermine is not recommended for use in 9-year-old children. This medication is an appetite suppressant approved only for adults with obesity, typically those 16 years and older, and more recently for adolescents aged 12 years and older in combination with topiramate for chronic weight management 2. Children's developing bodies and brains are particularly sensitive to stimulant medications like phentermine, which can cause serious side effects including increased heart rate, elevated blood pressure, insomnia, and potential impacts on growth and development. The most recent and highest quality study on the use of phentermine in adolescents, published in 2023, found that phentermine monotherapy is an effective and safe means for weight loss in pediatric patients when combined with lifestyle interventions, but the mean baseline age of the patients in this study was 15.63 years, and there is no data to support its use in children as young as 9 years old 3. For children with weight concerns, the appropriate approach involves comprehensive care under pediatric supervision, focusing on healthy eating habits, regular physical activity, adequate sleep, and limited screen time. Medical interventions for childhood obesity should be age-appropriate and might include family-based behavioral therapy or, in severe cases, specialized pediatric weight management programs. Any medication for weight management in children should only be considered in exceptional circumstances by pediatric specialists, and phentermine specifically is not an appropriate option for children of any age.
Some key points to consider when evaluating the use of phentermine in children include:
- The potential for serious side effects, including increased heart rate and elevated blood pressure 4
- The lack of data to support the use of phentermine in children under the age of 12 2
- The importance of comprehensive care under pediatric supervision for children with weight concerns
- The need for age-appropriate medical interventions for childhood obesity, such as family-based behavioral therapy or specialized pediatric weight management programs.
Overall, the potential risks and lack of data to support the use of phentermine in children as young as 9 years old make it an inappropriate option for this age group, and alternative approaches to weight management should be considered.