For weight loss, the FDA-approved naltrexone-containing option is naltrexone/bupropion extended-release, sold as Contrave, titrated to 32 mg naltrexone and 360 mg bupropion daily. Naltrexone alone is not FDA-approved for weight loss, and low-dose naltrexone is used off-label with less direct evidence. Dosing should be clinician-guided 1.
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See if you qualify →What is the usual naltrexone dose for weight loss?
The clearest answer is that naltrexone by itself does not have an FDA-approved weight-loss dose. The FDA-approved naltrexone-containing product for chronic weight management is Contrave, which contains naltrexone 8 mg and bupropion 90 mg per extended-release tablet 1.
Contrave is labeled for eligible adults with obesity, or adults with overweight plus at least one weight-related condition, when used with a reduced-calorie diet and increased physical activity 1. It is different from full-dose naltrexone products used for alcohol use disorder or opioid use disorder.
The FDA-approved naltrexone-containing dose: Contrave
The FDA label for Contrave describes a 4-week dose-escalation schedule. By week 4, the labeled maintenance dose is 2 tablets twice daily, or 32 mg naltrexone and 360 mg bupropion daily 1.
Why naltrexone alone is different from naltrexone/bupropion
Naltrexone is an opioid receptor antagonist, meaning it blocks opioid receptors, including the mu-opioid receptor. Bupropion affects norepinephrine and dopamine signaling. Together, the two drugs are thought to act on appetite and reward pathways linked with food cravings and reward-based eating 2.
That combination is why data from Contrave studies should not be treated as proof that naltrexone alone will cause the same weight loss. The benefit and the side effects come from the combination, especially because bupropion adds seizure, blood pressure, and mental health warnings 1.
How is Contrave usually titrated for weight management?
Contrave is titrated over 4 weeks on the FDA label. This slow increase is meant to improve tolerability, especially nausea, headache, and other early side effects 1.
| Treatment week | FDA-label dose described for Contrave | Total daily dose |
|---|---|---|
| Week 1 | 1 tablet each morning | 8 mg naltrexone / 90 mg bupropion |
| Week 2 | 1 tablet each morning and 1 tablet each evening | 16 mg naltrexone / 180 mg bupropion |
| Week 3 | 2 tablets each morning and 1 tablet each evening | 24 mg naltrexone / 270 mg bupropion |
| Week 4 and after | 2 tablets each morning and 2 tablets each evening | 32 mg naltrexone / 360 mg bupropion |
This table reports the FDA-labeled schedule; it is not a personal dosing plan. People with side effects, blood pressure changes, medication interactions, or contraindications need clinician guidance before starting or changing therapy 1.
Why the dose is increased slowly
In clinical use, slow titration helps clinicians separate expected early side effects from warning signs. In trials of naltrexone/bupropion, nausea, constipation, headache, vomiting, dizziness, insomnia, dry mouth, and diarrhea were among the common adverse reactions 1.
What clinicians monitor during dose changes
- Blood pressure and heart rate, because Contrave can raise both in some patients 1.
- Mood, anxiety, sleep, and suicidal thoughts, because bupropion carries antidepressant-class warnings 1.
- Seizure risk, including past seizure, eating disorder history, alcohol or sedative withdrawal, and interacting medicines 1.
- Opioid exposure, because naltrexone can trigger withdrawal in people with physical opioid dependence 1.
- Liver history, because naltrexone exposure is higher in hepatic impairment and serious liver injury has been reported with naltrexone products 1.
Is low-dose naltrexone used for weight loss?
Low-dose naltrexone, or LDN, usually means naltrexone doses far below the 50 mg tablets used in substance-use treatment. LDN is used off-label in several areas, but weight-loss evidence is much weaker than the evidence for FDA-approved weight-management medications 3.
Typical LDN dose ranges discussed in clinical practice
Published LDN reviews commonly describe low-dose naltrexone as about 1 to 5 mg per day, with 4.5 mg often used in small studies of pain and inflammatory conditions 3. Those numbers come from LDN literature, not from an FDA-approved weight-loss label.
What the evidence does and does not show for weight loss
The honest answer is that LDN has not been proven as a stand-alone weight-loss medication in large obesity trials. Some clinicians discuss it when inflammation, pain, or cravings are part of a broader health picture, but direct weight-loss outcomes for LDN remain uncertain 3.
Why LDN should not be made by splitting full-dose tablets
LDN doses are much smaller than standard naltrexone tablets; published LDN reviews commonly describe doses around 1 to 5 mg per day 3. Splitting or crushing full-dose tablets can lead to inaccurate dosing and is not the same as using a properly compounded low-dose tablet from a licensed pharmacy. At Chia, low-dose naltrexone tablets are compounded through US state-licensed 503A pharmacies when prescribed after clinician review.
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Considering low-dose naltrexone?
Chia offers low-dose naltrexone tablets, with plans currently starting at $59/mo. Treatment starts with a short online health questionnaire reviewed by a licensed US provider. A prescription requires a medical evaluation and is not guaranteed. Compounded medications from 503A pharmacies are not FDA-approved.
Does naltrexone work for weight loss by itself?
Naltrexone alone has not shown the same weight-loss evidence as naltrexone/bupropion. The stronger data are for the combination product studied as chronic weight-management therapy, but it also has combination-specific risks 2.
Evidence for naltrexone alone
Older studies of opioid antagonists explored appetite and eating behavior, but naltrexone alone did not become an FDA-approved obesity medicine. This matters because the labeled weight-loss indication belongs to the naltrexone/bupropion extended-release combination, not to naltrexone monotherapy 1.
Evidence for naltrexone plus bupropion
In the COR-I trial, adults with obesity or overweight were assigned to naltrexone sustained-release 32 mg plus bupropion sustained-release 360 mg, naltrexone 16 mg plus bupropion 360 mg, or placebo for 56 weeks, along with lifestyle intervention. The 32 mg/360 mg group lost more weight than placebo, but nausea, constipation, headache, vomiting, dizziness, insomnia, and dry mouth were more common 4. Individual results vary.
In the COR-BMOD trial, naltrexone/bupropion 32 mg/360 mg was studied with intensive behavior modification for 56 weeks. The combination group had greater weight loss than placebo with behavior therapy, but adverse events and discontinuations also occurred, so benefits and tolerability must be weighed together 5.
Why lifestyle changes are still part of treatment
Contrave is labeled as an add-on to reduced-calorie diet and increased physical activity, not as a replacement for those habits 1. In trials, medication was studied alongside lifestyle support, so it is not accurate to separate the drug effect from the full treatment plan.
Who may be eligible for naltrexone-containing weight-loss medication?
Naltrexone/bupropion is labeled for certain adults with BMI-based criteria. Eligibility also depends on opioid use, seizure risk, blood pressure, pregnancy status, liver health, mental health history, and other medications 1.
BMI and weight-related condition criteria for FDA-approved therapy
The Contrave label includes adults with an initial BMI of 30 kg/m² or greater, or 27 kg/m² or greater with at least one weight-related condition such as hypertension, type 2 diabetes, or dyslipidemia 1. BMI is only one part of the medical review.
When naltrexone may not be appropriate
- Current opioid use or physical opioid dependence, because naltrexone can trigger withdrawal 1.
- Uncontrolled hypertension, because naltrexone/bupropion can increase blood pressure and heart rate 1.
- Seizure disorder, bulimia, anorexia nervosa, or abrupt alcohol, benzodiazepine, barbiturate, or antiepileptic drug withdrawal, because bupropion can increase seizure risk 1.
- Pregnancy, because weight loss is not recommended during pregnancy and Contrave is contraindicated in pregnancy 1.
- Use of other bupropion-containing products, monoamine oxidase inhibitors, or certain interacting medicines 1.
Opioid use, withdrawal risk, and surgery planning
Naltrexone blocks opioid receptors. People taking opioid pain medicine, opioid use disorder treatment, or illicit opioids can have sudden withdrawal if they take naltrexone. It can also make opioid pain medicines less effective, so surgery and emergency pain plans should be discussed before treatment 1.
What side effects and warnings should patients know?
Naltrexone-containing weight-loss medication can help some eligible adults in studies, but side effects and contraindications are central to the decision. A clinician should review risks before prescribing and during dose changes 1.
Common side effects
Common adverse reactions in Contrave trials included nausea, constipation, headache, vomiting, dizziness, insomnia, dry mouth, and diarrhea 1. Nausea is one reason the labeled schedule increases gradually over several weeks.
Serious warnings and when to seek medical care
The Contrave label includes warnings for suicidal thoughts and behaviors, seizures, increases in blood pressure or heart rate, hepatotoxicity, angle-closure glaucoma, hypoglycemia risk in patients with type 2 diabetes using diabetes medicines, and opioid-related risks 1. Seek urgent care for severe allergic symptoms, chest pain, severe mood changes, seizure, signs of liver injury, or severe withdrawal symptoms.
Pregnancy, breastfeeding, seizure risk, blood pressure, and liver disease
Contrave is contraindicated in pregnancy, and the label advises caution around breastfeeding because bupropion and metabolites are present in human milk 1. Seizure risk, uncontrolled hypertension, and liver disease can also change whether this medication is appropriate 1.
How does naltrexone compare with GLP-1 weight-loss medications?
Naltrexone/bupropion works mainly through brain appetite and reward pathways, while GLP-1-based medicines act through gut-brain hormone pathways that affect appetite, fullness, and glucose regulation. The choice is not only oral versus injection; safety history, goals, contraindications, and tolerability all matter 1, 6, 7.
| Option | Drug class and mechanism | FDA-label weight-management dosing or study context | Key safety issues |
|---|---|---|---|
| Contrave | Naltrexone/bupropion extended-release; opioid receptor antagonist plus norepinephrine/dopamine reuptake inhibitor | FDA label titrates to 32 mg naltrexone / 360 mg bupropion daily by week 4 1 | Opioid withdrawal risk, seizure risk, blood pressure/heart rate increases, mood warnings, liver concerns |
| Semaglutide active ingredient | GLP-1 receptor agonist; Wegovy is the FDA-approved semaglutide brand for chronic weight management | The Wegovy label starts at 0.25 mg once weekly and titrates over 16 weeks toward maintenance doses of 1.7 mg or 2.4 mg once weekly 6 | GI side effects, gallbladder disease, pancreatitis warning, contraindication with personal/family history of medullary thyroid carcinoma or MEN2 |
| Tirzepatide active ingredient | Dual GIP/GLP-1 receptor agonist; Zepbound is the FDA-approved tirzepatide brand for chronic weight management | The Zepbound label starts at 2.5 mg once weekly for 4 weeks, then increases to 5 mg once weekly; maintenance doses include 5 mg, 10 mg, or 15 mg once weekly 7 | GI side effects, gallbladder disease, pancreatitis warning, thyroid C-cell tumor warning, hypoglycemia risk with some diabetes medicines |
| Compounded GLP-1 options through licensed 503A pharmacies | Compounded semaglutide or compounded tirzepatide prescribed after clinician review when appropriate | Provider-guided dosing; compounded formulations do not have FDA-evaluated outcomes data | Safety depends on medical screening, pharmacy quality, dose oversight, and avoiding unlicensed sources |
Naltrexone/bupropion vs semaglutide
Semaglutide is a GLP-1 receptor agonist. Wegovy is the FDA-approved semaglutide product for chronic weight management, while Ozempic is a semaglutide product approved for type 2 diabetes. Chia offers compounded semaglutide injections through licensed 503A pharmacies when prescribed after online provider review; compounded formulations are not FDA-approved and do not have FDA-evaluated outcomes data.
Naltrexone/bupropion vs tirzepatide
Tirzepatide is a dual GIP/GLP-1 receptor agonist. Zepbound is the FDA-approved tirzepatide product for chronic weight management, while Mounjaro is approved for type 2 diabetes. Chia offers tirzepatide tablets and injections, with microdosing plans available when clinically appropriate; compounded tirzepatide formulations and microdosing plans are not FDA-approved.
When a clinician might discuss an oral option, an injectable option, or both
An oral option may appeal to someone who wants to avoid injections, but it may be a poor fit with seizure risk, uncontrolled blood pressure, or opioid use. An injectable GLP-1 option may fit metabolic goals for some patients, but nausea, pancreatitis history, gallbladder disease, thyroid cancer contraindications, cost, and pregnancy plans all matter 6, 7.
Low-dose naltrexone at Chia: tablets, eligibility, and clinician review
Chia offers low-dose naltrexone tablets, not Contrave and not bupropion/naltrexone combination therapy. Plans for LDN tablets currently start at $59/mo, and every prescription requires review by a licensed US provider.
What Chia offers today
Chia’s current catalog lists low-dose naltrexone tablets. It does not list Contrave or bupropion/naltrexone extended-release combination therapy. If weight loss is your main goal, our providers may instead evaluate whether a GLP-1 option, such as semaglutide injection or tirzepatide tablets or injection, is clinically appropriate.
| Chia option | Forms Chia offers | Current starting price | How it relates to weight management |
|---|---|---|---|
| Low-Dose Naltrexone | Tablets | From $59/mo | Off-label for weight-related goals; not the FDA-approved Contrave combination |
| Semaglutide | Injection | From $249/mo | GLP-1 option evaluated for weight management when clinically appropriate |
| Tirzepatide | Tablets and injection; microdosing plans available | Tablets from $249/mo; injection from $299/mo | Dual GIP/GLP-1 option evaluated for weight management when clinically appropriate; compounded tablets and microdosing plans are not FDA-approved |
| Weight + Energy | NAD+ injection plus choice of GLP-1 | From $309/mo | Protocol option for patients whose clinician recommends a GLP-1 plus NAD+; the combined protocol and compounded components are not FDA-approved |
| Weight + Muscle | Sermorelin injection plus choice of GLP-1 | From $329/mo | Protocol option for patients whose clinician recommends a GLP-1 plus sermorelin; the combined protocol and compounded components are not FDA-approved |
How Chia’s online evaluation works
Chia is 100% online. You complete a short health questionnaire, then a licensed US provider reviews your history, medications, goals, and safety factors. If treatment is appropriate, medications are compounded in the US by state-licensed 503A compounding pharmacies and shipped to your door. You can message your care team through the patient portal between visits.
How Chia’s weight-loss options differ from LDN
LDN at Chia is not positioned as Contrave and is not the same as an FDA-approved weight-loss combination product. For weight management, our GLP-1 care paths include compounded semaglutide injection, compounded tirzepatide tablets or injection, and protocols such as Weight + Energy or Weight + Muscle, when a licensed provider determines they fit.
What should you ask your clinician before taking naltrexone for weight loss?
Before using naltrexone for a weight-related goal, ask whether the plan is FDA-approved Contrave, off-label naltrexone alone, or low-dose naltrexone. That distinction changes the evidence, dose range, safety review, and follow-up plan.
Medication and opioid-use questions
- Do I take any opioid pain medicine, cough medicine, or medication for opioid use disorder?
- If I need surgery or emergency pain treatment, how should naltrexone be handled?
- Do any of my medicines contain bupropion or interact with bupropion?
- Am I using alcohol, sedatives, or seizure-threshold-lowering medicines in a way that changes my risk?
Mental health, seizure, blood pressure, and liver questions
Ask how your clinician will monitor mood, sleep, anxiety, blood pressure, heart rate, liver history, and seizure risk. These issues are part of the FDA-labeled warning profile for naltrexone/bupropion 1.
How to discuss alternatives if weight loss is the main goal
If your main goal is weight loss, ask which options match your medical history and preferences: naltrexone/bupropion, GLP-1-based therapy, nutrition support, activity changes, sleep care, or a combination. At Chia, you can start with the online eligibility quiz so a licensed provider can review whether one of our listed options is appropriate.
3-min quiz
Start with a clinician-reviewed plan
Chia offers low-dose naltrexone tablets, compounded semaglutide injections, and tirzepatide tablets or injections through an online medical evaluation. A prescription is never guaranteed, and compounded medications from 503A pharmacies are not FDA-approved.
FAQ
The FDA-labeled maintenance dose for Contrave is 2 tablets twice daily, for a total of 32 mg naltrexone and 360 mg bupropion per day 1. This is label information, not personal dosing advice.
Naltrexone 50 mg tablets are used for substance-use indications, not as an FDA-approved weight-loss dose 1. Do not use or change naltrexone for weight loss without a clinician’s guidance.
LDN is commonly discussed in the range of about 1 to 5 mg per day in published low-dose naltrexone literature 3. LDN for weight-related goals is off-label and is not the same as Contrave.
Contrave trials measured weight change over months, not days. The label also recommends reassessing response after 12 weeks at the maintenance dose 1. Individual results vary, and side effects may appear earlier.
Naltrexone alone is not FDA-approved for weight loss. The FDA-approved naltrexone-containing weight-management medication is naltrexone/bupropion extended-release, sold as Contrave 1.
Only a clinician who knows your history can answer that. There may be cases where more than one pathway is discussed, but medication interactions, nausea, blood pressure, mental health history, and opioid exposure must be reviewed.
People currently taking opioids or with physical opioid dependence should avoid naltrexone unless a clinician has planned safe opioid discontinuation 1. Other concerns include acute hepatitis, significant liver disease, pregnancy, seizure risk with combination therapy, and uncontrolled blood pressure 1.
Follow the instructions from your prescriber or the medication label. Do not double up doses unless your clinician specifically tells you to do so.
References
- 1.U.S. Food and Drug Administration. Contrave (naltrexone hydrochloride and bupropion hydrochloride) extended-release tablets prescribing information. 2024.
- 2.Apovian CM, Aronne L, Rubino D, et al. A randomized, phase 3 trial of naltrexone SR/bupropion SR on weight and obesity-related risk factors (COR-II). Obesity. 2013.
- 3.Toljan K, Vrooman B. Low-dose naltrexone (LDN)—review of therapeutic utilization. Medical Sciences. 2018.
- 4.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. The Lancet. 2010.
- 5.Wadden TA, Foreyt JP, Foster GD, et al. Weight loss with naltrexone SR/bupropion SR combination therapy as an adjunct to behavior modification: the COR-BMOD trial. Obesity. 2011.
- 6.U.S. Food and Drug Administration. Wegovy (semaglutide) injection prescribing information. 2024.
- 7.U.S. Food and Drug Administration. Zepbound (tirzepatide) injection prescribing information. 2025.
- 8.Garvey WT, Mechanick JI, Brett EM, et al. American Association of Clinical Endocrinologists and American College of Endocrinology comprehensive clinical practice guidelines for medical care of patients with obesity. Endocrine Practice. 2016.
About this article
Chia Health Editorial Team — Evidence-reviewed health education
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.
AI tools may assist with research and drafting. Chia's editorial team reviews source use, clarity, treatment information, and safety framing before publication. A clinician is named only after explicit sign-off. Read our editorial standards.
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