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Zepbound vs Contrave: Tirzepatide Injection vs Oral Naltrexone-Bupropion

Zepbound (tirzepatide, Eli Lilly) vs Contrave (naltrexone-bupropion, Currax Pharmaceuticals)

Last verified 2026-05-28

By Eli Marsden · Founding Editor
Editorially reviewed (not clinically reviewed) · How we verify contentLast reviewed

The verdict

For raw efficacy, Zepbound wins decisively: SURMOUNT-1 showed -20.9% body weight at 72 weeks on the 15 mg dose versus -6.1% for Contrave in COR-I at 56 weeks. Zepbound also has an FDA-approved OSA indication (SURMOUNT-OSA, 2024) that Contrave lacks. Contrave's edge is practical: it is fully oral, ~$99/month cash, and avoids GLP-1-class GI burden. Zepbound makes sense when the goal is maximum loss; Contrave fits patients who cannot inject, cannot afford GLP-1 pricing, or have appetite-driven eating.

Side-by-side comparison

FieldZepboundContrave
Drug classDual GIP/GLP-1 receptor agonistOpioid antagonist + aminoketone antidepressant
Route & frequencySubcutaneous injection, once weeklyOral tablet, twice daily
Pivotal trial weight loss-20.9% at 72 weeks (SURMOUNT-1, 15 mg)-6.1% at 56 weeks (COR-I, full dose)
FDA approval (chronic weight management)November 2023September 2014
Additional FDA-approved indicationsModerate-to-severe OSA in adults with obesity (Dec 2024, per SURMOUNT-OSA)None beyond chronic weight management
Typical US cash price$349-$499/month via LillyDirect vials (dose-dependent)~$99/month via Currax cash-pay program
Most common adverse eventsNausea (~29%), diarrhea, constipation, vomitingNausea, constipation, headache, insomnia, dry mouth
Boxed warningThyroid C-cell tumors (rodent finding)Suicidal thoughts and behaviors in young adults (bupropion class)
Notable contraindicationsPersonal/family history of medullary thyroid carcinoma or MEN 2Uncontrolled hypertension, seizure disorders, chronic opioid use, MAOI use

Frequently asked questions

How much more weight loss does Zepbound deliver compared to Contrave?

In their respective pivotal trials, Zepbound 15 mg produced -20.9% body weight at 72 weeks (SURMOUNT-1), while Contrave at full dose produced -6.1% at 56 weeks (COR-I). That is roughly 3-4x more weight loss with Zepbound, though the trials differ in duration and population, so the comparison is directional rather than head-to-head.

Is Contrave a cheaper alternative to Zepbound?

Yes. Contrave's Currax cash-pay program runs around $99/month, while Zepbound through LillyDirect ranges roughly $349-$499/month depending on dose. The trade-off is efficacy: patients paying less for Contrave will, on average, lose substantially less weight.

Can Contrave treat sleep apnea like Zepbound?

No. Zepbound is the first medication FDA-approved for moderate-to-severe obstructive sleep apnea in adults with obesity, based on SURMOUNT-OSA (Malhotra 2024 NEJM). Contrave has no OSA indication and was not studied for that endpoint.

Who is Contrave the better fit for despite lower efficacy?

Patients who cannot or will not inject, cannot afford GLP-1 pricing, do not tolerate GLP-1 GI side effects, or have prominent food cravings and reward-driven eating, since Contrave's bupropion-naltrexone mechanism targets central reward pathways. It is also a reasonable option when insurance covers it but excludes GLP-1s.

What boxed warnings should I know about for each drug?

Zepbound carries a boxed warning for thyroid C-cell tumors based on rodent studies; it is contraindicated in patients with personal or family history of medullary thyroid carcinoma or MEN 2. Contrave carries a boxed warning for suicidal thoughts and behaviors in children, adolescents, and young adults, inherited from the bupropion component.

Can Zepbound and Contrave be combined?

Combination therapy is not FDA-approved or studied in pivotal trials and is generally not recommended outside of specialist obesity-medicine care. Bupropion has CNS-stimulating effects and Zepbound suppresses appetite via gut hormones, so stacking them without supervision risks overlapping side effects without clear added benefit.

References

  1. 1.Jastreboff. Jastreboff 2022 NEJM (SURMOUNT-1) NEJM. 2022. PMID: 35658024.
  2. 2.Greenway. Greenway 2010 Lancet (COR-I) Lancet. 2010. PMID: 20673995.
  3. 3.Malhotra. Malhotra 2024 NEJM (SURMOUNT-OSA) NEJM. 2024. PMID: 38912654.

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