How Quickly Does Adipex Work?

Adipex-P (phentermine hydrochloride) is a weight loss pill used to help people with obesity lose up to 10% of their body weight over a period of 12 weeks. The medication reaches its peak concentrations in the body in 3 to 4.4 hours.

Adipex-P (phentermine hydrochloride) is a weight loss pill used together with diet and exercise to treat obesity. It is a stimulant similar to an amphetamine and acts as an appetite suppressant that affects the central nervous system. 

Patients who are candidates for weight loss drug therapy include those individuals with a body mass index (BMI) 30 kg/m2 or greater, or a BMI of 27 to 29.9 kg/m2 with weight-related comorbidities, who have been unable to achieve doctor-prescribed weight-loss goals with lifestyle modifications. 

The medication in Adipex-P, phentermine, is taken orally and absorbed into the body via the gastrointestinal tract. After ingestion, the medication reaches its peak concentrations in the body in 3 to 4.4 hours, but it takes weeks to work as intended for weight loss. 

Adipex-P can help people lose up to an average of 5% total body weight and studies have shown that over a period of 12 weeks, people can lose as much as 10% of their body weight. Adipex-P is designed for use along with healthy eating, physical activity, and healthy lifestyle changes. It has been proven to reduce weight when taken as directed and combined with diet, exercise, and behavior modifications. 

However, Adipex-P is only approved for short-term (12 weeks) use because it has frequent side effects and the potential for abuse. For this reason, Adipex-P is not recommended for use in patients with coronary heart disease, uncontrolled high blood pressure (hypertension), hyperthyroidism, or in patients with a history of drug abuse.

Side effects of Adipex-P include:

• Dizziness
• Dry mouth
• Difficulty sleeping (insomnia)
• Increased heart rate
• Increased blood pressure 
• Constipation
• Irritability 
• Nervousness
• Nausea
• Vomiting
• Diarrhea
• Constipation