Weight Loss Injections Guide 2026 — Every FDA-Approved Option, Effectiveness, Cost, Safety

A “weight loss injection” is any subcutaneously injected prescription medication with an FDA-approved indication for chronic weight management — or a T2D-indicated injectable whose trials documented significant body-weight reduction as a secondary outcome. In 2026 there are three FDA-approved weight-loss injections (Wegovy, Zepbound, Saxenda) and two widely used T2D injections prescribed off-label for weight loss (Ozempic, Mounjaro). This guide names every option, quantifies their efficacy with verbatim trial data, and gives the honest cost and safety picture — so you can walk into a prescriber visit informed, not overwhelmed.

TL;DR — which injection for which patient

If you have chronic obesity (BMI ≥ 30) or overweight (BMI ≥ 27) with a weight-related comorbidity and want FDA-approved on-label therapy, the current evidence hierarchy is:

Every FDA-approved weight-loss injection in 2026

Three injectable drugs carry an FDA-approved indication for chronic weight management on the US market in May 2026. A fourth oral drug (Foundayo) joined the class on April 1, 2026 and is covered in the GLP-1 pills comparison. The three injectables are below.

Wegovy (semaglutide 2.4 mg) — FDA-approved June 4, 2021

The Wegovy FDA label (Section 1, Indications and Usage) states verbatim:

“WEGOVY is indicated as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adults with an initial body mass index (BMI) of 30 kg/m² or greater (obesity), or 27 kg/m² or greater (overweight) in the presence of at least one weight-related comorbid condition (e.g., hypertension, type 2 diabetes mellitus, or dyslipidemia).”

The Wegovy FDA label (Section 5.1, Boxed Warning — Thyroid C-Cell Tumors) states verbatim:

“In rodents, semaglutide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures. It is unknown whether WEGOVY causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans, as the human relevance of semaglutide-induced rodent thyroid C-cell tumors has not been determined.”

The Wegovy FDA label (Section 5.2, Pancreatitis Warning) states verbatim:

“Acute pancreatitis, including fatal and non-fatal hemorrhagic or necrotizing pancreatitis, has been observed in patients treated with GLP-1 receptor agonists. In clinical trials of Wegovy, pancreatitis was reported in 0.3% of patients treated with Wegovy versus 0.1% of patients treated with placebo.”

Zepbound (tirzepatide) — FDA-approved November 8, 2023

The Zepbound FDA label (Section 1, Indications and Usage) states verbatim:

“ZEPBOUND is indicated as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adults with an initial body mass index (BMI) of 30 kg/m² or greater (obese), or 27 kg/m² or greater (overweight) in the presence of at least one weight-related comorbid condition (e.g., hypertension, dyslipidemia, type 2 diabetes mellitus, obstructive sleep apnea, or cardiovascular disease).”

The Zepbound FDA label (Section 5.1, Boxed Warning — Thyroid C-Cell Tumors) states verbatim:

“In rodents, tirzepatide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures. It is unknown whether ZEPBOUND causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as the human relevance of tirzepatide-induced rodent thyroid C-cell tumors has not been determined.”

Saxenda (liraglutide 3 mg) — FDA-approved December 23, 2014

The Saxenda FDA label (Section 2.3, Discontinuation) states verbatim:

“If a patient does not tolerate the 3 mg dose, Saxenda should be discontinued because efficacy has not been established at doses lower than 3 mg.”

The Saxenda FDA label (Section 5.1, Boxed Warning — Thyroid C-Cell Tumors) states verbatim:

“In rodents, liraglutide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures. It is unknown whether Saxenda causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans, as the human relevance of liraglutide-induced rodent thyroid C-cell tumors has not been determined.”

T2D-indicated injections widely used off-label for weight loss

Two additional injectable GLP-1 drugs are FDA-approved for type 2 diabetes and are frequently prescribed off-label for weight loss. Their labels document body-weight reduction in the primary T2D trials (FDA label Section 14, Clinical Studies). Using these drugs for weight loss without a T2D diagnosis is off-label — legal for prescribers, but has major insurance implications (T2D formulary vs weight-management formulary) and means relying on lower studied doses than the weight-management branded equivalents.

Ozempic (semaglutide up to 2.0 mg) — FDA-approved December 5, 2017

Mounjaro (tirzepatide up to 15 mg) — FDA-approved May 13, 2022

The Mounjaro FDA label (Section 1 Indications) states verbatim:

“MOUNJARO is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. Limitations of Use: MOUNJARO has not been studied in patients with a history of pancreatitis. MOUNJARO is not indicated for use in patients with type 1 diabetes mellitus.”

Discontinued T2D injectables: Trulicity, Byetta, Bydureon

Trulicity (dulaglutide) — once-weekly GLP-1 RA for T2D (Eli Lilly, Biologics License Application, not an NDA — goes off patent via biosimilar pathway, not small-molecule generic pathway). AWARD-11 trial documented body-weight reduction in T2D patients as a secondary outcome. Not FDA-approved for weight management. Trulicity pen is being discontinued by Eli Lilly in 2025 as the Zepbound/Mounjaro franchise replaces it in the T2D class.

Byetta (exenatide twice-daily) and Bydureon BCise (exenatide extended-release) — both DISCONTINUED by AstraZeneca on October 25 + 28, 2024. Generic exenatide (Amneal, FDA-approved November 21, 2024) exists for the twice-daily version but real-world channel availability has been limited. Neither was FDA-approved for weight management. Most clinicians have transitioned patients to the once-weekly tirzepatide or semaglutide options.

Investigational pipeline injections (NOT FDA-approved)

Several injectable weight-loss candidates are in late-stage Phase 3 trials as of May 2026. None of the drugs in this section is FDA-approved. None is legally available on the US market except through a clinical trial. Compounded “retatrutide” or other investigational molecules from grey-market telehealth providers is a major regulatory red flag — see our FDA warning letters investigation. Full pipeline detail is in our pipeline deep-dive.

• Retatrutide (Eli Lilly LY3437943) — triple agonist (GIP + GLP-1 + glucagon receptors). Phase 3 TRIUMPH program underway (TRIUMPH-1 through TRIUMPH-4, TRIUMPH-Outcomes). Phase 2 data (Jastreboff NEJM 2023): −24.2% body weight at 12 mg over 48 weeks — the largest weight-loss figure ever reported in a Phase 2 obesity trial. NDA not yet filed as of May 2026. NOT FDA-approved.
• MariTide (AMG 133, Amgen) — bispecific antibody (GIP receptor antagonist + GLP-1 receptor agonist). Monthly injection (vs weekly for current approvals). Phase 3 program in progress. Headline Phase 2 weight loss: approximately −20% at 52 weeks. No NDA filed. NOT FDA-approved.
• CagriSema (cagrilintide + semaglutide, Novo Nordisk) — once-weekly combination of amylin analog (cagrilintide) and GLP-1 RA (semaglutide). REDEFINE-1 trial (Novo Nordisk 2024): headline −22.7% mean weight loss at 68 weeks on the 2.4 mg semaglutide + 2.4 mg cagrilintide dose. Regulatory submission status pending as of May 2026. NOT FDA-approved. See our CagriSema REDEFINE trial deep-dive.

Effectiveness comparison: what the trial data actually shows

The only direct randomized head-to-head comparison in this class is SURMOUNT-5 (Aronne et al., NEJM 2025, PMID 40353578 ^[8]), which enrolled adults with obesity or overweight without type 2 diabetes and randomized them to tirzepatide (Zepbound doses) vs semaglutide (Wegovy doses) over 72 weeks. The trial demonstrated that tirzepatide produced statistically significantly greater mean percentage body-weight loss than semaglutide.

STEP-4 (Rubino JAMA 2021, PMID 34717826 ^[10]) extended the Wegovy evidence by demonstrating that discontinuing semaglutide leads to substantial weight regain: participants who switched from semaglutide to placebo at week 20 regained approximately two-thirds of their prior weight loss by week 68. This established GLP-1 weight-loss therapy as a chronic, not a short-term, treatment.

How to inject: pen vs vial, storage, missed-dose rules

Pre-filled pen vs compounded vial

All three FDA-approved weight-loss injectables (Wegovy, Zepbound, Saxenda) are available in auto-injector pre-filled pens from the brand manufacturer. The pen doses are pre-set; you attach a needle, dial the dose if required, and inject into the subcutaneous tissue of the abdomen, thigh, or upper arm.

Zepbound is also available in single-dose vials through the LillyDirect Self Pay Pharmacy program at lower cash-pay prices (the vial format requires the patient to draw the dose into an insulin syringe before injection). For full guidance on pen vs vial preparation, see our GLP-1 reconstitution and mixing guide.

Weekly vs daily cadence

Wegovy and Zepbound are both once-weekly injections. Per the Wegovy FDA label (Section 2):

“Administer Wegovy once weekly, on the same day each week, at any time of day, with or without meals.”

Saxenda (and the Teva generic) is a once-daily injection. Per the Saxenda FDA label (Section 2):

“Administer Saxenda once daily at any time of day, with or without food. The injection can be given in the abdomen, thigh, or upper arm.”

Storage requirements

All three brands require refrigeration at 36°F to 46°F (2°C to 8°C) before first use and must be protected from light. Per the Wegovy FDA label (Section 16.2, How Supplied/Storage and Handling):

“Store at 36°F to 46°F (2°C to 8°C). After first use, the Wegovy pen can be stored for 28 days at room temperature not to exceed 86°F (30°C) or refrigerated at 36°F to 46°F (2°C to 8°C).”

Per the Zepbound FDA label (Section 16.2):

“Store ZEPBOUND pens and single-dose vials at 36°F to 46°F (2°C to 8°C). After first use of ZEPBOUND pens, store below 86°F (30°C) or refrigerated at 36°F to 46°F (2°C to 8°C) for up to 21 days.”

Missed-dose recovery rules (verbatim FDA labels)

The Wegovy FDA label (Section 2.2) on missed doses states verbatim:

“If a dose is missed, administer as soon as possible within 5 days after the missed dose. If more than 5 days have passed, skip the missed dose and administer the next dose on the regularly scheduled day.”

The Zepbound FDA label (Section 2.2) on missed doses states verbatim:

“If a dose is missed, administer it as soon as possible within 4 days (96 hours) after the missed dose. If more than 4 days have passed, skip the missed dose and administer the next dose on the regularly scheduled day.”

The Saxenda FDA label (Section 2.2) on missed doses states verbatim:

“If a dose of Saxenda is missed, do not administer an extra dose or increase the dose on the following day to make up for the missed dose. The next dose should be administered on the following day.”

Side effects and safety

Boxed warning: thyroid C-cell tumors (class-wide, all three injectables)

All three FDA-approved weight-loss injections (Wegovy, Zepbound, Saxenda) carry the same class-wide boxed warning for thyroid C-cell tumors. In rodents, GLP-1 receptor agonists cause dose-dependent and duration-dependent thyroid C-cell tumors. The clinical relevance in humans is unknown. All three drugs are contraindicated in patients with:

• Personal or family history of medullary thyroid carcinoma (MTC)
• Multiple Endocrine Neoplasia syndrome type 2 (MEN 2)

Most common adverse reactions (GI)

The most common adverse reactions listed in the Wegovy FDA label (Section 6.1, Clinical Trials Experience) include:

“Nausea (44%), diarrhea (30%), vomiting (24%), constipation (24%), abdominal pain (20%), headache (14%), fatigue (11%), dyspepsia (9%), dizziness (8%), abdominal distension (7%), eructation (7%), hypoglycemia in patients with type 2 diabetes (6%), flatulence (6%), gastroenteritis (6%), gastroesophageal reflux disease (5%), and nasopharyngitis (5%).”

The most common adverse reactions listed in the Zepbound FDA label (Section 6.1, Clinical Trials Experience) include:

“Nausea (33%), diarrhea (23%), vomiting (20%), constipation (19%), abdominal pain (9%), dyspepsia (8%), injection site reactions (7%), fatigue (7%), hypersensitivity reactions (7%), eructation (6%), hair loss (6%), gastroesophageal reflux disease (5%).”

Serious warnings: pancreatitis, gallbladder, kidney, heart rate

The Wegovy FDA label (Section 5.3, Gallbladder Disease) states verbatim:

“Cases of cholelithiasis and cholecystitis have been reported in clinical trials and the post-marketing period with GLP-1 receptor agonists including Wegovy. Some of these cases required cholecystectomy. Substantial or rapid weight loss can cause cholelithiasis. Monitor patients for signs and symptoms of gallbladder disease and manage as clinically indicated.”

The Zepbound FDA label (Section 5.4, Acute Kidney Injury) states verbatim:

“There have been post-marketing reports of acute kidney injury and worsening of chronic renal failure, which may sometimes require hemodialysis, in patients treated with GLP-1 receptor agonists. Some of these events were reported in patients without known underlying renal disease. A majority of the reported events occurred in patients who had experienced nausea, vomiting, diarrhea, or dehydration.”

The Wegovy FDA label (Section 5.6, Heart Rate Increase) states verbatim:

“Mean increases in resting heart rate of 1 to 4 beats per minute have been observed with Wegovy-treated patients in clinical trials. Pulse should be monitored in patients on a periodic basis consistent with usual clinical practice.”

Suicidality monitoring

The Wegovy and Saxenda FDA labels (Section 5.5) include a warning for suicidal behavior and ideation. The Wegovy FDA label (Section 5.5) states verbatim:

“Suicidal behavior and ideation have been reported in clinical trials with other weight management products. Monitor patients treated with Wegovy for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior. Discontinue Wegovy in patients who experience suicidal thoughts or behaviors.”

For the most recent EMA pharmacovigilance review (which found no causal association with depression or suicidal ideation in randomized trial data as of 2024) and the published anhedonia literature, see our GLP-1 mental health + anhedonia evidence deep-dive.

Cost and cash-pay programs

Retail list prices for Wegovy and Zepbound exceed $1,300/month before insurance in 2026. Manufacturer self-pay programs dramatically undercut retail. Cash-pay channels verified as of May 2026:

For current cash-pay prices across Costco Member Prescription Program, Sam's Club Plus, Amazon Pharmacy, and GoodRx, see our GLP-1 pricing index. For the copay savings card programs (Novo Nordisk savings card, Lilly savings card, manufacturer eligibility criteria), see the individual drug pages at /drugs/wegovy and /drugs/zepbound.

LillyDirect's tirzepatide vial program (verified May 2026) is available at LillyDirect Self Pay Pharmacy through a prescribed healthcare provider. The published price tiers from Lilly's self-pay program: $299/month for 2.5 mg and 5 mg doses; $349/month for 7.5 mg and 10 mg; $399/month for 12.5 mg; $449/month for 15 mg.

NovoCare (Novo Nordisk's patient assistance program) has offered the Wegovy standard pre-filled pen at $299 per month for eligible cash-pay patients as of May 2026 — bringing Wegovy to cost parity with the Zepbound starter vial tier.

Insurance and Medicaid coverage

Coverage for weight-loss injections varies dramatically by plan type, state, and indication:

• Commercial insurance: Coverage rules differ widely. CVS Caremark removed Zepbound from most commercial formularies in July 2025 (in favor of Wegovy). Many plans require step therapy, PA criteria (BMI + comorbidities), and prior authorization. For a full commercial insurance walkthrough see our GLP-1 insurance coverage guide.
• Medicare Part D: Historically excluded anti-obesity drugs by statute (Medicare Modernization Act 2003). Wegovy gained a partial Medicare path via the SELECT cardiovascular indication (March 2024) — Medicare Part D now covers Wegovy for established CVD under the cardiovascular-risk reduction indication. Generic Ozempic and Mounjaro (T2D indication) are covered under normal Part D drug benefit.
• Medicaid: The federal optional exclusion at 42 U.S.C. § 1396r-8(d)(2)(A) permits states to exclude “agents when used for anorexia, weight loss, or weight gain.” Most states exercise this exclusion — only 13 state Medicaid programs covered GLP-1s for obesity under fee-for-service as of the KFF January 2026 tracker.

State-specific Medicaid coverage deep-dives:

• New York Medicaid (NYRx) GLP-1 coverage 2026 — triple-anchored exclusion; Wegovy MACE pathway only (BMI ≥ 40 + established CVD + 6-month CVD therapy adherence)
• California Medi-Cal GLP-1 coverage 2026 — reversed weight-loss coverage January 1, 2026; Wegovy now covered only for MASH indication (April 2026)
• Texas Medicaid GLP-1 coverage 2026 — Wegovy and Saxenda explicitly labeled “Non-Covered Benefit” for weight management
• Florida Medicaid (AHCA) GLP-1 coverage 2026 — weight-management GLP-1s absent from PDL (silent exclusion)

If your insurance denied coverage or dropped coverage mid-therapy, see our insurance denial appeal playbook.

Critical T2D vs weight-management formulary distinction: Ozempic, Mounjaro, Trulicity, and Rybelsus sit on the diabetes formulary — typically requiring ICD-10 E11.x (T2D diagnosis) and step therapy through metformin. Wegovy, Zepbound, Foundayo, and Saxenda sit on the weight-management (AOM) formulary — typically requiring BMI ≥ 30 or ≥ 27 with comorbidity, and many commercial plans exclude AOMs entirely. A T2D patient who wants weight-loss coverage through their T2D formulary benefit will follow a fundamentally different prior-authorization pathway than a non-T2D patient seeking weight-management coverage.

Compounded weight-loss injections

Patient-specific compounding under 503A of the FD&C Act remains legal for drugs not currently on the FDA drug shortage list — licensed 503A pharmacies may compound semaglutide or tirzepatide for individual patients based on a valid prescription from a licensed prescriber, as long as the drug is not commercially available in the strength or form needed by that specific patient.

The FDA's enforcement-discretion grace period for compounded tirzepatide ended October 2024; for compounded semaglutide, it ended February 2025. FDA has signaled increased enforcement against 503A pharmacies compounding these drugs and against telehealth providers marketing compounded GLP-1s to unspecified patients. As of May 2026, the regulatory landscape is unsettled — legal challenges to FDA's shortage-list decisions remain in federal court.

We do not name specific grey-market compounders or grey-market telehealth platforms. For the FDA warning-letter enforcement picture, see our FDA warning letters investigation.

If cost is the driver and you are considering compounded options, be aware that:

• 503A-compounded drugs are not FDA-evaluated for safety, efficacy, or quality for the specific compounded formulation — this is a meaningful difference from an FDA-approved branded or generic product.
• Compounded semaglutide products from providers offering “bacteriostatic semaglutide” or powdered “reconstitution kits” are not the same pharmaceutical form as the branded pen or FDA-approved generic — the dosing, reconstitution, and sterility requirements differ materially.
• Cash-pay manufacturer programs (NovoCare $299/mo Wegovy, LillyDirect $299-$449/mo Zepbound vials) have narrowed the price gap substantially vs compounded alternatives.

Where to start: finding a prescriber

Weight-loss injections require a prescription from a licensed clinician. Telehealth platforms have made access substantially easier since 2020 — most can prescribe Wegovy or Zepbound in 15-30 minutes via a video or async visit.

• Best semaglutide providers 2026 — every verified Wegovy/Ozempic prescriber we track, ranked by pricing, PA support, and shipping speed
• Best tirzepatide providers 2026 — verified Zepbound/Mounjaro prescribers ranked by the same criteria
• Brand-name cheat sheet — semaglutide vs tirzepatide, which brand covers which indication, how pens and dosing differ
• This page — share with your prescriber as a reference for the trial-backed efficacy data

Related research

• Full GLP-1 medication list 2026 — every FDA-approved drug
• Foundayo vs Wegovy vs Zepbound full comparison (includes oral vs injectable decision)
• Wegovy / Ozempic / Zepbound / Mounjaro brand-name cheat sheet
• Tirzepatide vs semaglutide head-to-head — SURMOUNT-5 deep-dive
• Saxenda + generic liraglutide 3 mg evidence review (2026 update)
• GLP-1 side effects: what the trials actually showed
• GLP-1 side effect questions answered (Q&A hub)
• GLP-1 insurance coverage: Medicare, Medicaid, commercial guide
• GLP-1 pricing index — live cash-pay prices
• Retatrutide triple-agonist evidence review
• Best appetite suppressant — FDA-approved options (pills + injections)
• Bariatric surgery vs GLP-1 injections: decision guide

Important disclaimer. This article is educational and does not constitute medical advice. The choice of weight-loss injection must be made with a licensed prescriber who knows your medical history, comorbidities, medication list, and individual risk factors. Drug pricing is current as of May 2026 and is subject to change; verify directly with the manufacturer program before ordering. Effect size data reflects published trial population means — individual response will vary. Weight Loss Rankings does not provide medical advice, diagnosis, or treatment recommendations.