Phentermine's Impact on Treatment in Teens
Recruiting · 2 sites across 2 states
Always free
Study care at no cost to you
For your time and travel
Many studies pay you back
Most need no insurance or papers
Legal status usually isn't required; we'll tell you each study's requirements
Interpreters available
Ask for your language
Your choice
Voluntary — you can stop anytime
What is this study?
PhITT is a Phase IIb, multicenter, randomized, double-blind, placebo-controlled clinical trial evaluating the efficacy and safety of phentermine (16 mg daily) in adolescents aged 12 to \<18 years with obesity. Conducted across approximately 10 sites within the IDeA States Pediatric Clinical Trials Network (ISPCTN), the study aims to enroll up to 240 participants and then randomize up to 198 who meet eligibility criteria, randomized in a 2:1 ratio to phentermine or placebo over a 52-week treatment period, followed by a 2-week withdrawal assessment.
It is , overseen by an independent and licensed medical staff.
Read the full clinical description
PhITT is a Phase IIb, multicenter, randomized, double-blind, placebo-controlled clinical trial evaluating the efficacy and safety of phentermine (16 mg daily) in adolescents aged 12 to \<18 years with obesity. Conducted across approximately 10 sites within the IDeA States Pediatric Clinical Trials Network (ISPCTN), the study aims to enroll up to 240 participants and then randomize up to 198 who meet eligibility criteria, randomized in a 2:1 ratio to phentermine or placebo over a 52-week treatment period, followed by a 2-week withdrawal assessment.
Who this study is looking for
In plain language, from the study's own rules. The study team confirms the full details with you — this isn't a final yes or no.
✅ You may be able to join if…
- •Teens 12 to under 18 years old when they agree to join
- •Tanner stage 2 or higher at the screening visit (a measure of puberty stage)
- •Have obesity, defined as a BMI at or above the 95th percentile for age/sex or a BMI of 30 kg/m² or higher
- •Biological females must agree to use reliable birth control during the study (described as certain double-barrier or other specific options)
🚫 You may not be able to join if…
- •Anyone who is pregnant or breastfeeding, or who plans to become pregnant during the study
- •Teens who have certain heart problems (such as coronary artery disease, stroke, significant heart rhythm problems, or congestive heart failure) or other listed phentermine “contraindications”
- •Anyone with stage 2 hypertension or taking medicine to treat high blood pressure
- •Anyone with type 1 or type 2 diabetes, or using medicine to treat diabetes or prediabetes
- •Anyone with certain mental health risks, such as a recent suicide attempt or recent self-harm, PHQ-9 score 10 or higher, suicidal thoughts (C-SSRS type 4 or 5), or anorexia/bulimia (EAT-26 score 20 or higher)
Are you a good fit?
Simplified highlights. The study team always confirms the full details with you.
- ✓Adults roughly 12–17
- ✓A BMI around 95 or higher
- ✓Have Obesity / overweight
- !Some conditions may not be a fit: Type 2 diabetes, Heart / cardiovascular disease, High blood pressure
- !Not for people who are pregnant or breastfeeding
What to expect, step by step
- 1
Usually a few weeks
The study team checks whether the study is a good fit for you, with a visit and sometimes lab tests. You can ask any questions before deciding.
- 2
Treatment
If you join and choose to continue, you receive the study treatment and are watched closely by medical staff.
- 3
Follow-up
After treatment, the team checks on your health and confirms the visit schedule with you. You can leave the study at any point.
Has this treatment been tested before?
Yes. This treatment has already been through earlier human studies for safety before reaching this stage.
What you need to know before you apply
What is this study testing?+
PhITT is a Phase IIb, multicenter, randomized, double-blind, placebo-controlled clinical trial evaluating the efficacy and safety of phentermine (16 mg daily) in adolescents aged 12 to \<18 years with obesity. Conducted across approximately 10 sites within the IDeA States Pediatric Clinical Trials Network (ISPCTN), the study aims to enroll up to 240 participants and then randomize up to 198 who meet eligibility criteria, randomized in a 2:1 ratio to phentermine or placebo over a 52-week treatment period, followed by a 2-week withdrawal assessment.
Is it safe? Who makes sure of that?+
This is a mid-stage study (Phase 2), looking at safety and whether the treatment works. Every study is reviewed and monitored by an independent ethics board (called an IRB) whose job is to protect participants, and care is overseen by licensed medical staff. You'll be told the known risks before you agree to anything, and you can stop at any time.
Will I get a placebo instead of the real treatment?+
Some studies compare a treatment against a placebo (an inactive version), and some don't. If this one does, the study team will explain your chances of receiving the active treatment before you decide. Nothing is hidden from you.
Do I have to stop taking my current medications?+
It depends on the study. Some let you stay on your current medications and some ask you to adjust them. Never stop a medication on your own — the study team will review everything with you first.
Does it cost anything? Will I be paid?+
The study treatment and study-related visits are provided at no cost to you. Some studies also pay for your time; the coordinator can tell you if this one does. You should never be asked to pay to take part.
Do I need insurance? Will anyone ask about my immigration status?+
No. You do not need health insurance to take part in a research study, and you will not be asked about your immigration status to join. Taking part is about whether you're a medical fit for the study.
What if English isn't my first language?+
You have the right to understand everything before you agree. Study sites can often provide materials or an interpreter in your language — you can ask the coordinator for one.
Is my information private?+
Yes. Your health information is only shared with the study sites you choose to be contacted by, and only to help match and enroll you. It is never sold, and you can ask us to delete it at any time.
Some requirements (like specific lab values or timing) are confirmed directly by the study team, not by us.
Source: ClinicalTrials.gov · NCT07282340 · Locations: New Mexico · South Carolina