Best Prescription Weight-Loss Medications: How the FDA-Approved Options Actually Compare

The short answer

The most important distinction for buyers to understand: Wegovy (semaglutide 2.4 mg) and Zepbound (tirzepatide) are FDA-approved specifically for chronic weight management, while Ozempic (semaglutide) and Mounjaro (tirzepatide) contain the same active molecules but are FDA-approved for type 2 diabetes. Using Ozempic or Mounjaro for weight loss alone is off-label. That difference matters for insurance coverage, for your prescriber's documentation, and for what a legitimate provider can offer you.

This page explains how each medication works, who it tends to suit, the contraindications that rule people out, and the cost structure you will actually face, without inventing prices or efficacy figures. It is written for women weighing these options, including women navigating perimenopause and menopause, where weight-related decisions overlap with hormone therapy. It is informational only. This site does not sell, prescribe, or dispense medication.

What "best" really means when matching a drug to a person

"Best" in weight-loss medicine is not a ranking; it is a match. A drug that suits a 52-year-old woman with hypertension and no diabetes may be a poor fit for someone with a history of pancreatitis, a personal or family history of medullary thyroid carcinoma, or a seizure disorder. The FDA labels and NIDDK's patient guidance both frame these medications as tools used alongside reduced-calorie eating and increased physical activity, not replacements for them.

The practical variables that decide the match are your BMI and comorbidities (which set FDA eligibility), your tolerance for injections versus pills, your other diagnoses and medications (which create contraindications and interactions), and your coverage. Two people with identical weight can end up on different drugs because one has diabetes and one does not, or because one plan covers a GLP-1 and the other does not.

Because this is a match rather than a leaderboard, the useful question is not "which drug is strongest" but "which FDA-approved drug fits my body, my history, and what I can actually obtain and afford." The sections below give you the raw material to answer that with a licensed prescriber.

The GLP-1 and GLP-1/GIP class: semaglutide and tirzepatide

Semaglutide is a GLP-1 receptor agonist. It mimics glucagon-like peptide-1, a hormone your gut releases after eating, which increases feelings of fullness, slows how quickly the stomach empties, and helps regulate blood sugar. Tirzepatide is a dual agonist: it activates both the GLP-1 receptor and the GIP (glucose-dependent insulinotropic polypeptide) receptor. Both are once-weekly subcutaneous injections that patients self-administer, and both are started at a low dose and titrated upward over weeks to reduce gastrointestinal side effects.

The most common side effects across this class, per the FDA labels, are gastrointestinal: nausea, diarrhea, vomiting, constipation, and abdominal discomfort, which tend to be worst during dose escalation. The labels carry a boxed warning about thyroid C-cell tumors based on rodent studies, and both are contraindicated in people with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2. Pancreatitis, gallbladder problems, and interactions with other glucose-lowering drugs are also flagged.

This class draws the most attention because of the degree of weight change reported in the clinical trials that supported approval, but the FDA labels also make clear these are chronic-use medications: weight tends to return after stopping, so prescribers frame them as long-term therapy rather than a short course. That long-term framing is central to the cost conversation later on this page.

Weight-approved vs diabetes-approved: the distinction that changes everything

This is the single most misunderstood point in the category. Wegovy is semaglutide dosed and FDA-approved for chronic weight management. Ozempic is semaglutide FDA-approved for type 2 diabetes. Zepbound is tirzepatide FDA-approved for chronic weight management. Mounjaro is tirzepatide FDA-approved for type 2 diabetes. The active molecules pair up, but the approved indications do not.

Prescribing Ozempic or Mounjaro purely for weight loss, in a person without type 2 diabetes, is off-label use. Off-label prescribing is legal and common in medicine, but it has real consequences here: insurers frequently deny coverage for a diabetes drug used for weight, and a prescriber writing it off-label is making a clinical judgment they must document. If your goal is weight management and you do not have diabetes, the on-label products are Wegovy and Zepbound.

Understanding this also protects you from marketing sleight of hand. A telehealth ad selling "Ozempic for weight loss" is describing off-label use of a diabetes drug, not the FDA-approved weight-management pathway. Neither is inherently illegitimate, but you deserve to know which one you are being offered before you pay.

FDA eligibility: the BMI criteria on the label

The weight-management drugs are not approved for anyone who simply wants to lose a few pounds. The FDA label Indications define who qualifies. For the chronic weight-management products, eligibility begins at a body mass index (BMI) of 30 or higher, which is the clinical threshold for obesity.

Alternatively, you qualify at a BMI of 27 or higher, the overweight range, if you also have at least one weight-related comorbid condition. The labels give examples such as hypertension, type 2 diabetes, and dyslipidemia (abnormal cholesterol or triglycerides). This is why your other diagnoses matter so much: a weight-related condition can be the difference between qualifying and not.

A legitimate prescriber will confirm your BMI and review these conditions before writing a prescription. If an online seller offers you a GLP-1 without establishing that you meet the label criteria, that is a signal to slow down, not to celebrate a shortcut.

The established oral options: phentermine, phentermine-topiramate, naltrexone-bupropion, orlistat

The GLP-1 class is newer, but NIDDK still lists several older FDA-approved medications that remain relevant, especially for patients who cannot or prefer not to inject, or whose coverage does not extend to the newer drugs. Phentermine is an appetite suppressant approved for short-term use; it is a stimulant-type medication, which makes cardiovascular history and blood pressure central to whether it is appropriate.

Phentermine-topiramate combines that appetite suppressant with topiramate, a drug also used for seizures and migraine, in an extended-release formulation approved for chronic weight management. Naltrexone-bupropion pairs an opioid-receptor blocker with bupropion, an antidepressant and smoking-cessation drug, and is thought to act on appetite and reward pathways in the brain. Orlistat works differently from all of these: it blocks the absorption of a portion of dietary fat in the gut rather than acting on appetite, and it is the one option available both by prescription and, at a lower strength, over the counter.

Each of these carries its own contraindications. Topiramate-containing therapy is associated with birth-defect risk and is not used in pregnancy; bupropion lowers the seizure threshold and interacts with a personal history of seizures or eating disorders; phentermine's stimulant profile makes it unsuitable for uncontrolled hypertension or significant heart disease; orlistat's fat-blocking mechanism produces gastrointestinal effects and can affect absorption of fat-soluble vitamins. None of these is a lesser choice by default. For the right patient, an oral drug can be the better match than an injectable.

Side-by-side comparison of the FDA-approved options

The table below summarizes the medications NIDDK lists, the active ingredients, the FDA-approved use, and the form. It deliberately contains no efficacy percentages or dollar figures, because those vary by individual, formulation, and the day you check.

Use it to narrow the conversation, then confirm specifics against the current FDA label and with a licensed prescriber. A brand shown is one example of the ingredient, not an endorsement, and the same molecule can appear under more than one brand with a different approved use.

Who each medication tends to suit, and who it rules out

The GLP-1 and GLP-1/GIP injectables tend to suit people who meet the BMI criteria, can commit to long-term weekly injections, and have no personal or family history of medullary thyroid carcinoma or MEN 2. They are ruled out for those with that thyroid history and used cautiously in people with a history of pancreatitis or significant gallbladder disease. Because coverage and continuity matter for a chronic therapy, they suit people who have a realistic plan for staying on treatment.

Phentermine tends to suit shorter-term use in people with controlled blood pressure and no significant cardiovascular disease. Phentermine-topiramate can suit patients wanting an oral chronic-management option, but is unsuitable in pregnancy and requires attention to contraception because of topiramate's birth-defect risk. Naltrexone-bupropion can suit patients where appetite and reward-driven eating are prominent, but is ruled out by uncontrolled hypertension, seizure history, current opioid use, and certain eating-disorder histories.

Orlistat tends to suit people who prefer a non-systemic mechanism and can tolerate the gastrointestinal effects of unabsorbed dietary fat, and who are willing to manage fat-soluble vitamin intake. Across all of these, the deciding factors are your comorbidities and history, not a popularity ranking. A prescriber's job is to find the option your body will accept.

What women specifically should weigh: contraception, pregnancy, and menopause

A concrete, label-based difference separates the two injectable molecules for women of reproductive age: tirzepatide (Zepbound and Mounjaro) can reduce the effectiveness of oral contraceptives, according to its FDA label, which advises additional or alternative contraception around the start of treatment and dose increases. Semaglutide (Wegovy and Ozempic) does not carry that oral-contraceptive warning. If you rely on the pill and are choosing between molecules, this is a real deciding factor to raise with your prescriber.

None of these weight-loss medications is intended for use during pregnancy, and several, particularly topiramate-containing therapy, carry specific reproductive risks. Women who could become pregnant should discuss contraception and timing before starting, and anyone who becomes pregnant on these drugs should contact their prescriber promptly. This is a safety conversation, not an afterthought.

For women in perimenopause and menopause, weight changes often coincide with decisions about menopause hormone therapy. Weight-loss medication and hormone therapy address different problems and are evaluated separately. For questions about hormone therapy itself, the American College of Obstetricians and Gynecologists (ACOG) publishes patient guidance, and this site keeps dedicated cost pages for hormone therapy rather than quoting those prices here. Do not assume a weight drug substitutes for, or conflicts with, hormone therapy without asking a clinician who sees your full picture.

Understanding the cost structure without chasing a single number

The most damaging mistake buyers make is anchoring on one dollar figure they saw somewhere. There is no single price for these drugs, because five different cost structures coexist. The manufacturer's list price is the sticker figure. Your insured copay is what you pay if your plan covers the drug for your indication, and it can be a fraction of list or nothing. Manufacturer savings cards can lower cost for eligible commercially insured patients under specific terms. Cash or self-pay programs offer a set price to people without applicable coverage. Compounded versions occupy a separate, non-FDA-approved category discussed below.

Because these structures move independently and change over time, the only responsible place to get a current figure is the manufacturer's own coverage-and-savings page. Lilly publishes Zepbound and Mounjaro savings terms; Novo Nordisk publishes Wegovy and Ozempic savings terms through its NovoCare and brand pages. Whatever number you see there is time-stamped and subject to change, and eligibility conditions apply. Treat any third-party site quoting a precise "average" or "typical" price with suspicion.

The table below maps the routes without inventing figures, so you know which door to knock on. For a chronic therapy you may stay on for a long time, the durable question is not this month's price but which structure you will still qualify for a year from now, especially if a savings card has time limits or your coverage changes.

Compounded GLP-1s and the FDA warning you should know before you buy

Compounded semaglutide and tirzepatide are not FDA-approved products. Compounding pharmacies prepare medications outside the FDA approval process, and the FDA has warned about unapproved and compounded GLP-1 products, including concerns about ingredient sourcing, dosing errors, and products marketed by sellers that are not legitimate pharmacies. The availability of compounded versions has shifted alongside the branded drugs' shortage status, which is a moving regulatory situation rather than a stable option.

This matters because compounded products are often marketed at a lower price, which makes them attractive on a chronic therapy. A lower price on an unapproved product is not the same value as a lower copay on an FDA-approved one. When a compounded vial arrives without the manufacturing oversight that stands behind an approved drug, the cost you cannot see is quality assurance.

If you are considering a compounded route, ask directly whether the product is FDA-approved (compounded versions are not), who is compounding it and under what state pharmacy license, and what the prescriber's rationale is. A legitimate clinician can explain the tradeoff honestly. A seller who obscures it is telling you something.

How to obtain a prescription the legitimate way

These are prescription medications. In the United States, obtaining them legally means a licensed prescriber evaluates you, confirms you meet the clinical and BMI criteria, reviews your history and contraindications, and sends a prescription to a licensed pharmacy that dispenses an FDA-approved product. That path can run through your primary care physician, an obesity-medicine specialist, or a telehealth service that uses prescribers licensed in your state.

A legitimate telehealth flow will assess eligibility before offering a drug, ask about your medical history and current medications, involve a real prescriber consultation, and route your prescription to a licensed pharmacy. It will not skip the clinical evaluation, will not sell you a prescription drug without a prescriber, and will be transparent about whether it is offering an FDA-approved product or a compounded one.

This site is affiliate-only: it does not sell, prescribe, or dispense anything. Where it links out, it points you toward comparing providers and pharmacies licensed in your state so you can start that legitimate evaluation, never toward buying a drug without a prescription.

A practical way to bring this to your prescriber

Come to the appointment with three things ready. First, your numbers: your current BMI and any weight-related conditions such as hypertension, type 2 diabetes, or high cholesterol, because these set your FDA eligibility. Second, your history: any personal or family history of medullary thyroid carcinoma or MEN 2, pancreatitis, gallbladder disease, seizures, eating disorders, and your current medications, including birth control, since those drive contraindications and interactions.

Third, your practical constraints: whether you can commit to a weekly injection or prefer a pill, and what your insurance is likely to cover. If you take oral contraceptives, name it, because that alone can steer the choice between semaglutide and tirzepatide. If you are perimenopausal or menopausal and also weighing hormone therapy, say so, so the two decisions are handled together rather than in isolation.

The goal of the visit is not to request a specific brand you saw advertised. It is to let a clinician who can see your whole picture match you to the FDA-approved option your body will tolerate and your coverage will support. That match, not a leaderboard, is what "best" means here.

Frequently asked questions

What is the best prescription weight-loss medication?

There is no single best option for everyone. The FDA-approved choices NIDDK lists include the GLP-1/GIP injectables (semaglutide and tirzepatide), phentermine, phentermine-topiramate, naltrexone-bupropion, and orlistat. The right one depends on your BMI, other conditions, whether you have type 2 diabetes, your tolerance for injections versus pills, and your coverage. Matching is done with a licensed prescriber.

What is the difference between Wegovy and Ozempic, or Zepbound and Mounjaro?

Wegovy and Ozempic are both semaglutide; Zepbound and Mounjaro are both tirzepatide. Within each pair, the first (Wegovy, Zepbound) is FDA-approved for chronic weight management, while the second (Ozempic, Mounjaro) is FDA-approved for type 2 diabetes. Using the diabetes-approved brands for weight loss alone is off-label, which affects coverage and how a prescriber documents your care.

Do I qualify for these weight-loss drugs?

For the FDA-approved weight-management medications, the label indications generally start at a BMI of 30 or higher, or a BMI of 27 or higher if you also have at least one weight-related condition such as hypertension, type 2 diabetes, or abnormal cholesterol. A licensed prescriber confirms your BMI and reviews your conditions before writing a prescription.

Does semaglutide or tirzepatide interact with birth control?

Tirzepatide (Zepbound and Mounjaro) can reduce the effectiveness of oral contraceptives according to its FDA label, which advises additional or alternative contraception around starting and dose increases. Semaglutide (Wegovy and Ozempic) does not carry that oral-contraceptive warning. If you rely on the pill, raise this with your prescriber when choosing between the two.

How much do prescription weight-loss medications cost?

There is no single price. List price, insured copay, manufacturer savings card, cash self-pay, and compounded versions are entirely different cost structures. The only reliable place for a current figure is the manufacturer's own coverage-and-savings page, and even that is time-stamped and subject to change. Avoid third-party sites quoting a precise average or typical price.

Are compounded semaglutide and tirzepatide safe and legal?

Compounded semaglutide and tirzepatide are not FDA-approved products, and the FDA has warned about unapproved and compounded GLP-1 products. Their availability has shifted with the branded drugs' shortage status. A lower price on an unapproved product is not equivalent to a lower copay on an FDA-approved one. Ask any seller directly whether the product is FDA-approved and under what pharmacy license it is compounded.

Can I buy these drugs online without a prescription?

No. These are prescription medications. Obtaining them legally means a licensed prescriber evaluates you, confirms you meet the criteria, and sends a prescription to a licensed pharmacy that dispenses an FDA-approved product. A legitimate telehealth service assesses eligibility and involves a real prescriber. Any seller offering these drugs without a prescription is a warning sign, not a shortcut.

Are there non-injectable prescription options?

Yes. Phentermine, phentermine-topiramate, naltrexone-bupropion, and orlistat are FDA-approved oral options NIDDK lists. Each has its own contraindications: topiramate-containing therapy is not used in pregnancy, naltrexone-bupropion has seizure and eating-disorder cautions, phentermine's stimulant profile requires attention to heart and blood-pressure history, and orlistat works by blocking dietary fat absorption. For the right patient, an oral drug can be the better match than an injectable.

Primary sources

1. NIDDK (NIH), Prescription Medications to Treat Overweight & Obesity
2. FDA Prescribing Information, Wegovy (semaglutide) injection
3. FDA Prescribing Information, Zepbound (tirzepatide) injection
4. FDA Prescribing Information, Ozempic (semaglutide) injection
5. FDA Prescribing Information, Mounjaro (tirzepatide) injection
6. FDA Drugs@FDA approved-drug database
7. Lilly, Zepbound coverage & savings
8. Novo Nordisk, Save on Wegovy
9. NovoCare, Wegovy cost & coverage
10. Lilly, Mounjaro savings & resources
11. ACOG, Hormone Therapy for Menopause (patient FAQ)