When to add Weight-Loss pills? new study tests timing for teens

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Provision of signed and dated informed assent form; * Provision of signed and dated informed parental consent form from at least 1 legal parent/guardian; * Stated willingness to comply with all study procedures and availability for the duration of the study; * BMI \>/= 1.2 times the 95th percentile or BMI \>/= 35 Kg/m2, whichever is lower; * Tanner stage \>/= 2; * Male or female, aged 12-17 at time of consenting; * For females of reproductive potential: when sexually active, agreement to use highly effective contraception (oral contraceptive pill, intra-uterine device (IUD), or implant) during study participation; * For males of reproductive potential: use of condoms or other methods to ensure effective contraception with partner. Exclusion Criteria: * Contraindications to phentermine or topiramate use according to package inserts, including: history of glaucoma; current or recent (\< 14 days) use of monoamine oxidase inhibitor; known hypersensitivity to sympathomimetic amines; current pregnancy, plans to become pregnant, or if sexually active refusal to use 2 forms of birth control; history of cardiac disease including coronary artery disease; clinically significant cardiac arrhythmias; heart failure or uncontrolled hypertension; * Diabetes (type 1 or 2); * Presence of cardiac pacemaker; * Current or recent (\<6 months prior to enrollment) use of weight loss medication(s); * Current use of weight-altering medication(s) (e.g., atypical antipsychotic, metformin) unless dose has been stable for past 6 months; * Current use of other sympathomimetic amine such as attention-deficit hyperactivity disorder (ADHD) stimulants; * Seizure disorder (other than infantile febrile seizure); * Previous bariatric surgery; * Recent initiation of change in dose (\< 3 months prior to enrollment) of anti-hypertensive or lipid medication(s); * Tobacco use * History of or current diagnosis of schizophrenia, psychosis, mania, chemical dependency; * Unstable depression or anxiety that has required hospitalization in the past year; * Any history of suicide attempt; * Suicidal ideation or self-harm within 12 months prior to enrollment; * Bicarbonate \< 18 mmol/L; * Creatinine \> 1.2 mg/dL; * History of cholelithiasis; * History of nephrolithiasis; * Untreated thyroid disorder; * Hyperthyroidism; * Breastfeeding