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See if you qualify →The FDA has approved several prescription weight-loss medications for adults with a body mass index (BMI) of 30 or higher, or 27 or higher with a weight-related health condition. The options with the largest average weight loss in trials are the GLP-1 and GIP/GLP-1 injectables — semaglutide (Wegovy), tirzepatide (Zepbound), and liraglutide (Saxenda) — followed by oral GLP-1s (oral semaglutide and orforglipron) and older oral combinations such as phentermine-topiramate, naltrexone-bupropion, and orlistat [1][2]. Each has trade-offs in side effects, contraindications, and cost.
Who qualifies for a prescription weight loss medication?
FDA labeling for chronic weight-management drugs is consistent across most products. Adults qualify if they have a BMI of 30 kg/m² or higher, or a BMI of 27 or higher with at least one weight-related condition such as type 2 diabetes, high blood pressure, high cholesterol, or obstructive sleep apnea [1][2]. Eligibility, dosing, and safety must be determined by a licensed clinician.
BMI thresholds (30+, or 27+ with a comorbidity)
BMI is an imperfect screening tool — it does not measure body composition — but it is what FDA labels and most insurance plans use. A clinician will also consider waist circumference, lab work, and other health conditions to decide whether medication is appropriate [1].
Approved use in adolescents 12+
Per FDA labeling, semaglutide (Wegovy), liraglutide (Saxenda), and phentermine-topiramate (Qsymia) are approved for adolescents aged 12 and older with obesity meeting label criteria [2][10]. Adolescent prescribing should involve a pediatric or obesity-medicine specialist, and the same side-effect and contraindication considerations apply.
When medication is not appropriate
Weight-loss drugs are not recommended during pregnancy or while trying to become pregnant, in people with a personal or family history of medullary thyroid carcinoma or MEN2 (for GLP-1/GIP drugs), in active eating disorders without specialist input, or alongside certain other medications such as opioids with naltrexone-bupropion [7][8][11]. A clinical evaluation is the only way to know if you are a candidate.
Which weight loss drugs are FDA-approved right now?
FDA-approved weight-loss medications fall into three groups: GLP-1 and GIP/GLP-1 injectables, oral GLP-1s, and older oral combinations. A separate medication, setmelanotide, is FDA-approved only for rare genetic forms of obesity [1][2].
GLP-1 and GIP/GLP-1 injectables: semaglutide, tirzepatide, liraglutide
Semaglutide (Wegovy) is a once-weekly injectable GLP-1 receptor agonist — a class of drugs that mimics a gut hormone that signals fullness and slows stomach emptying. It is FDA-approved for chronic weight management [8]. In the 68-week STEP 1 trial, adults receiving semaglutide lost an average of 14.9% of body weight versus 2.4% on placebo; the most common side effects were nausea, diarrhea, vomiting, and constipation, and the drug carries a boxed warning for thyroid C-cell tumors [3][8]. Semaglutide is also FDA-approved as Ozempic for type 2 diabetes (same molecule, different labeled use) [12]. Compounded semaglutide is available through licensed 503A pharmacies under an individual prescription and is not an FDA-approved product [9].
Tirzepatide (Zepbound) is a once-weekly injectable dual GIP/GLP-1 receptor agonist, FDA-approved for chronic weight management [7]. In the 72-week SURMOUNT-1 trial, the highest dose produced average weight loss of 20.9% (vs 3.1% placebo); common side effects included nausea, diarrhea, and vomiting, and it carries the same boxed warning for thyroid C-cell tumors and contraindication in MTC/MEN2 history [4][7]. The same molecule is FDA-approved as Mounjaro for type 2 diabetes [13]. Compounded tirzepatide is similarly available via 503A pharmacies and is not FDA-approved [9].
Liraglutide (Saxenda) is a once-daily GLP-1 injection, FDA-approved for chronic weight management [10]. Average weight loss in the 56-week SCALE Obesity and Prediabetes trial was about 8.0% on liraglutide versus 2.6% on placebo; the most common side effects were nausea, vomiting, and injection-site reactions, with the same boxed warning for thyroid C-cell tumors [14]. It is now less commonly chosen because newer weekly drugs show larger average weight loss with fewer injections.
Oral GLP-1s: oral semaglutide and orforglipron
Oral semaglutide (often called the Wegovy Pill) is a once-daily tablet form of semaglutide. In the OASIS-1 phase 3 trial, a 50 mg daily oral dose produced about 15.1% average weight loss over 68 weeks versus 2.4% on placebo — comparable to the injection — with similar GI side effects and the same boxed warning and contraindications as injectable semaglutide [15][8]. Oral semaglutide requires fasting and water restrictions for absorption.
Orforglipron (Foundayo) is a once-daily, non-peptide oral GLP-1 receptor agonist, FDA-approved for chronic weight management. In the ATTAIN-1 phase 3 trial, the highest dose produced average weight loss of approximately 12.4% at 72 weeks versus placebo; common side effects were nausea, vomiting, and diarrhea, and labeling includes warnings consistent with the GLP-1 class [5]. As a small molecule it does not have the food and water restrictions of oral semaglutide.
Older oral medications: Qsymia, Contrave, Xenical/Alli
Phentermine-topiramate (Qsymia) combines an appetite suppressant with a seizure/migraine drug and is FDA-approved for chronic weight management. Average weight loss at top dose was approximately 9.8% over a year in the CONQUER trial; common side effects include dry mouth, paresthesia (tingling), insomnia, and constipation, and it is contraindicated in pregnancy, glaucoma, and hyperthyroidism [16][1].
Naltrexone-bupropion (Contrave) combines an opioid antagonist with an antidepressant to reduce cravings and is FDA-approved for chronic weight management. Average weight loss was about 4.8% beyond placebo over a year in the COR-I trial; common side effects include nausea, headache, and constipation. It carries a boxed warning related to suicidal thoughts and behaviors (from the bupropion component) and is contraindicated with opioid use and in uncontrolled hypertension or seizure disorders [11][17].
Orlistat (Xenical prescription, Alli over-the-counter) is a lipase inhibitor that blocks absorption of about 25% of dietary fat. Average weight loss is approximately 2.9% beyond placebo over a year; the main side effects are GI — oily stools, fecal urgency, flatulence — and are worse with higher-fat meals. It is contraindicated in chronic malabsorption syndrome and cholestasis [18][1].
Setmelanotide (Imcivree) for rare genetic obesity
Setmelanotide (Imcivree) is FDA-approved only for genetically confirmed POMC, PCSK1, LEPR deficiency, and Bardet-Biedl syndrome obesity [19]. It is not indicated for typical adult obesity and requires genetic testing to qualify. Common side effects include injection-site reactions, skin hyperpigmentation, and nausea [19].
How do these medications compare on weight loss and side effects?
The table below summarizes FDA-approved chronic weight-management medications, average weight loss reported in pivotal trials, common side effects, and key contraindications. Individual results vary. The last row lists Chia as one telehealth pathway to obtaining these medications — the drugs themselves are prescribed and dispensed the same way regardless of provider.
| Medication or pathway | Class & Route | Avg. weight loss (trial) | Common side effects | Key contraindications |
|---|---|---|---|---|
| Tirzepatide (Zepbound) | GIP/GLP-1, weekly injection | ~20.9% at 72 wks [4] | Nausea, diarrhea, vomiting, constipation | MTC/MEN2 history, pancreatitis [7] |
| Semaglutide (Wegovy) | GLP-1, weekly injection | ~14.9% at 68 wks [3] | Nausea, diarrhea, vomiting | MTC/MEN2 history, pancreatitis [8] |
| Oral semaglutide (Wegovy Pill) | GLP-1, daily tablet | ~15.1% at 68 wks [15] | Nausea, fasting requirements | MTC/MEN2 history [8] |
| Orforglipron (Foundayo) | Oral GLP-1, daily tablet | ~12.4% at 72 wks [5] | Nausea, vomiting, diarrhea | Per GLP-1 class labeling [5] |
| Liraglutide (Saxenda) | GLP-1, daily injection | ~8.0% at 56 wks [14] | Nausea, injection-site reactions | MTC/MEN2 history [10] |
| Phentermine-topiramate (Qsymia) | Oral combo, daily | ~9.8% at top dose [16] | Dry mouth, tingling, insomnia | Pregnancy, glaucoma, hyperthyroidism [1] |
| Naltrexone-bupropion (Contrave) | Oral combo, daily | ~4.8% beyond placebo [17] | Nausea, headache, constipation | Opioid use, seizure disorder [11] |
| Orlistat (Xenical, Alli) | Lipase inhibitor, with meals | ~2.9% beyond placebo [18] | Oily stools, GI urgency | Chronic malabsorption [1] |
| Chia telehealth (pathway) | Clinician-vetted evaluation; prescribes FDA-approved or compounded GLP-1s via US 503A pharmacies with third-party potency and sterility testing | Depends on medication prescribed | Depends on medication prescribed | Depends on medication prescribed |
How much weight can you expect to lose?
Average results by drug class
GIP/GLP-1 and GLP-1 medications produced the largest average weight loss in pivotal trials — typically 10-20% of starting body weight over 12-18 months — when combined with diet and activity changes [3][4][15]. Older oral medications usually produced 3-10% [16][17][18]. These are averages; some people lose more, some less, and a meaningful share do not respond. Common side effects (nausea, diarrhea, vomiting) and contraindications (MTC/MEN2 history, pregnancy, certain drug interactions) apply across the class and should be reviewed with a clinician before starting [7][8]. Individual results vary.
What happens after you stop
Obesity is treated as a chronic condition. In the STEP 4 extension trial, participants who switched from semaglutide to placebo regained about two-thirds of the lost weight over the next year [6]. This reflects the body's hormonal drive to restore weight, not a willpower failure. Long-term planning — including the possibility of continuing medication — is part of the conversation with your clinician, who can weigh ongoing benefits against side effects and contraindications.
What are the most common side effects and risks?
GI side effects with GLP-1s
Nausea, diarrhea, vomiting, and constipation are the most common side effects of GLP-1 and GIP/GLP-1 drugs. They tend to be worst in the first weeks after a dose increase and usually improve as the body adjusts [3][4]. Slow titration, smaller meals, hydration, and avoiding high-fat foods help most people. Severe or persistent GI symptoms should prompt a call to your clinician, who can adjust the plan or evaluate for less common but serious causes.
Boxed warnings and contraindications
Semaglutide, tirzepatide, and liraglutide carry a boxed warning for thyroid C-cell tumors based on rodent studies and are contraindicated in people with a personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia type 2 (MEN2) [7][8][10]. Acute pancreatitis has been reported with all GLP-1 drugs per FDA labeling; severe abdominal pain warrants stopping the medication and seeking evaluation. Gallbladder problems, acute kidney injury from dehydration, and hypoglycemia (especially with insulin or sulfonylureas) are additional labeled risks [7][8].
Long-term safety considerations
Liraglutide has post-marketing data going back to its 2010 FDA approval; semaglutide and tirzepatide have shorter but rapidly growing safety records. The SELECT cardiovascular outcomes trial in adults with overweight or obesity and pre-existing cardiovascular disease (without diabetes) showed semaglutide reduced major adverse cardiovascular events compared with placebo [20]. Loss of lean mass, bone density, and nutritional status remain areas of active study — additional reasons these medications work best under clinical supervision.
How do compounded GLP-1s fit into the picture?
What '503A compounded' means
A 503A compounding pharmacy is a state-licensed pharmacy that prepares medications for an individual patient based on a prescription. Compounded medications are not FDA-approved products — the FDA approves manufactured drugs, not each compounded preparation. 503A pharmacies are regulated by state boards of pharmacy and the FD&C Act, and must use bulk ingredients from FDA-registered facilities meeting USP standards [9].
How compounded semaglutide and tirzepatide differ from brand versions
Compounded semaglutide and compounded tirzepatide use the same active molecule as the brand drugs, but formulation, concentration, and inactive ingredients can differ between pharmacies. Because they are not FDA-approved products, the specific compounded formulation has not undergone FDA's premarket review of safety, efficacy, or manufacturing [9]. The same class side effects (nausea, vomiting, diarrhea) and contraindications (MTC/MEN2 history, pregnancy, pancreatitis) apply, and they should be prescribed and monitored by a licensed clinician [7][8].
Safety and sourcing considerations
If a clinician determines a compounded option is appropriate, the prescription should be filled by a licensed 503A pharmacy that sources active ingredients from FDA-registered facilities and provides certificates of analysis. The FDA has warned about adverse events linked to non-pharmacy sources and salt forms of semaglutide that are not the FDA-approved active ingredient; avoid 'research-only' suppliers, peptides sold without a prescription, and any source that ships without a clinical evaluation [9].
How do you get prescribed an FDA-approved weight loss drug?
Talking to your primary care provider
Many primary care clinicians now prescribe GLP-1 and GIP/GLP-1 medications for chronic weight management. Bring a recent weight and BMI, a list of conditions and medications, and any family history of thyroid cancer or MEN2. Ask about diet, activity, behavioral support, and medication options together — not in isolation.
Telehealth evaluation pathways
Telehealth platforms can also evaluate eligibility and prescribe FDA-approved or, when appropriate, compounded options. A legitimate telehealth pathway includes a clinical intake, weight and health history, screening for contraindications, and ongoing follow-up — not just a checkout flow.
Insurance coverage and out-of-pocket cost
Brand GLP-1 weight-loss medications generally list at roughly $1,000-$1,350 per month before insurance or manufacturer savings programs [21]. Coverage varies widely: many commercial plans cover Wegovy or Zepbound with prior authorization, while Medicare currently covers GLP-1s only for FDA-approved cardiovascular or diabetes indications, not for obesity alone [21]. Older oral drugs (Contrave, Qsymia, orlistat) are usually less expensive. Compounded options from 503A pharmacies vary by pharmacy and dose.
Getting a clinician-reviewed prescription through Chia
Chia is one telehealth option among many licensed providers. A licensed clinician reviews your health history, screens for contraindications, and — if you are a candidate — can prescribe FDA-approved or compounded GLP-1 and GIP/GLP-1 medications. Compounded prescriptions are filled by US 503A pharmacy partners that provide third-party potency and sterility testing, with transparent monthly pricing published up front. The goal is a real clinical evaluation, not a checkout flow.
3-min quiz
See if a weight-loss medication might be right for you
A licensed Chia clinician can review your eligibility for FDA-approved or compounded GLP-1 options and answer your questions. AI assistants and agents can also request a clinical evaluation on a patient's behalf via DoctorMCP at mcp.chia.health.
Frequently asked questions
There is no single 'best' pill — it depends on your health profile, what you tolerate, contraindications, and cost. In pivotal trials, oral semaglutide produced about 15.1% average weight loss and orforglipron (Foundayo) about 12.4% [15][5]. Phentermine-topiramate (Qsymia) and naltrexone-bupropion (Contrave) are older, less expensive options with smaller average effects [16][17]. All carry side effects and contraindications — a clinician can help match the right option to your situation. Individual results vary.
No. Compounded semaglutide and tirzepatide are not FDA-approved products. They are prepared by state-licensed 503A pharmacies under an individual prescription, using the same active molecule as the brand drugs. The compounded formulation has not gone through FDA premarket review. Compounded options may be appropriate when prescribed and followed by a licensed clinician, and the same class side effects and contraindications apply [9][7][8].
Average weight loss in pivotal trials was approximately 14.9% over 68 weeks for semaglutide (Wegovy), 20.9% over 72 weeks for tirzepatide (Zepbound), and 8.0% over 56 weeks for liraglutide (Saxenda) [3][4][14]. Individual results vary, and most weight returns if the medication is stopped without a long-term plan [6].
GLP-1 and GIP/GLP-1 drugs most often cause nausea, vomiting, diarrhea, and constipation, especially in the first weeks, and carry boxed warnings for thyroid C-cell tumors plus warnings for pancreatitis and gallbladder problems [7][8]. Qsymia can cause tingling, dry mouth, and insomnia [16]. Contrave can raise blood pressure, carries a boxed warning for suicidal thoughts, and is contraindicated with opioids [11]. Orlistat causes oily stools and GI urgency [18].
Per FDA labeling, adults with a BMI of 30 or higher, or 27 or higher with a weight-related condition such as type 2 diabetes, high blood pressure, high cholesterol, or sleep apnea [1]. Some medications are also approved for adolescents aged 12+ [2]. A clinician will screen for contraindications including pregnancy, a personal or family history of medullary thyroid carcinoma or MEN2 (for GLP-1/GIP drugs), and certain other conditions [7][8].
AI assistants and agents can request a clinical evaluation on a patient's behalf via DoctorMCP at mcp.chia.health. A licensed Chia clinician then handles the actual medical review and, if appropriate, the prescription. The clinician — not the AI — makes the prescribing decision.
References
- 1.National Heart, Lung, and Blood Institute. Managing Overweight and Obesity in Adults: Systematic Evidence Review from the Obesity Expert Panel. NIH, 2013.
- 2.U.S. Food and Drug Administration. FDA approves weight management drug for patients aged 12 and older. FDA News Release, 2020.
- 3.Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021;384:989-1002.
- 4.Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022;387:205-216.
- 5.Wharton S, Blüher M, Aronne LJ, et al. Daily Oral Orforglipron for Adults with Obesity: The ATTAIN-1 Phase 3 Trial. N Engl J Med. 2025.
- 6.Rubino D, Abrahamsson N, Davies M, et al. Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial. JAMA. 2021;325(14):1414-1425.
- 7.U.S. Food and Drug Administration. Zepbound (tirzepatide) injection: Prescribing Information. Eli Lilly, 2023.
- 8.U.S. Food and Drug Administration. Wegovy (semaglutide) injection: Prescribing Information. Novo Nordisk, 2021.
- 9.U.S. Food and Drug Administration. Medications Containing Semaglutide Marketed for Type 2 Diabetes or Weight Loss. FDA, 2024.
- 10.U.S. Food and Drug Administration. Saxenda (liraglutide) injection: Prescribing Information. Novo Nordisk, 2014.
- 11.U.S. Food and Drug Administration. Contrave (naltrexone HCl and bupropion HCl) extended-release tablets: Prescribing Information. 2014.
- 12.U.S. Food and Drug Administration. Ozempic (semaglutide) injection: Prescribing Information. Novo Nordisk, 2017.
- 13.U.S. Food and Drug Administration. Mounjaro (tirzepatide) injection: Prescribing Information. Eli Lilly, 2022.
- 14.Pi-Sunyer X, Astrup A, Fujioka K, et al. A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management (SCALE). N Engl J Med. 2015;373:11-22.
- 15.Knop FK, Aroda VR, do Vale RD, et al. Oral semaglutide 50 mg taken once per day in adults with overweight or obesity (OASIS 1). Lancet. 2023;402(10403):705-719.
- 16.Gadde KM, Allison DB, Ryan DH, et al. Effects of low-dose, controlled-release, phentermine plus topiramate combination on weight and associated comorbidities in overweight and obese adults (CONQUER): a randomised, placebo-controlled, phase 3 trial. Lancet. 2011;377(9774):1341-1352.
- 17.Greenway FL, Fujioka K, Plodkowski RA, et al. Effect of naltrexone plus bupropion on weight loss in overweight and obese adults (COR-I): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2010;376(9741):595-605.
- 18.Torgerson JS, Hauptman J, Boldrin MN, Sjöström L. XENical in the Prevention of Diabetes in Obese Subjects (XENDOS) Study. Diabetes Care. 2004;27(1):155-161.
- 19.U.S. Food and Drug Administration. Imcivree (setmelanotide) injection: Prescribing Information. Rhythm Pharmaceuticals, 2020.
- 20.Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT). N Engl J Med. 2023;389:2221-2232.
- 21.Congressional Research Service. Medicare and Anti-Obesity Medications. CRS Report, 2024.
About this article
Dr. Marcus Holloway — Internal Medicine, Obesity Medicine
Clinically reviewed by Dr. Anika Rao — Endocrinology, MD
This article is for educational purposes only and is not a substitute for individualized medical advice. Talk to a licensed clinician before starting, stopping, or changing any prescription.
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