Naltrexone
Naltrexone is a medication frequently associated with branded preparations like Mysimba and Adepend. It serves as a medicinal tool for supporting patients during recovery and weight control.
Key points
- By occupying opioid receptors in the brain, it blunts the usual reward response and reduces cravings for alcohol or opioids.
- For weight control, it is combined with diet and exercise, curbing cravings via appetite pathways in the central nervous system.
- Because it can block the effect of opioid pain relief or cough medicines, a clear washout period is needed beforehand.
What is Naltrexone?
Naltrexone is an opioid antagonist medication designed to block the effects of opioids in the body. It works at the receptor level to change how the brain responds to these substances. Various forms, such as prolonged-release tablets and film-coated tablets, exist to suit different therapeutic requirements and metabolic needs for individuals following a specific care plan.
What Naltrexone is used for
This medication is primarily employed as part of a broader therapeutic approach for Alcohol Dependence and Opioid Dependence. By blocking the receptors in the brain that respond to opioids, it serves a distinct function in long-term treatment strategies. Additionally, specific combinations containing this ingredient are utilised for Weight Management when combined with structured diet and exercise plans.
How does Naltrexone work?
Naltrexone functions by binding to opioid receptors in the brain, effectively occupying these sites so that other opioid substances cannot trigger the same chemical response. This mechanism reduces the urge to consume alcohol or opioids, as the typical reward response associated with these substances is blunted. For those using it for weight control, the medication influences appetite regulation pathways in the central nervous system to reduce food cravings.
Naltrexone brands and forms
The range of medicines for this ingredient includes both originator brands and various generic formulations. Patients may encounter different formats such as prolonged-release tablets or standard film-coated tablets, chosen based on the desired duration of action and the specific treatment goal. Selecting the correct preparation relies on the clinical assessment provided by a health practitioner during the evaluation phase.
Safety overview for Naltrexone
What to check before using this medicine
Verify that all current medications and health conditions have been discussed with a clinical provider. Individuals with liver or kidney health factors require monitoring. Review the patient information leaflet included with the product to understand the correct usage parameters.
Possible reactions and tolerability
Common reactions can include nausea, headache, or sleep disturbances during the initial phase of treatment. These effects often settle as the body adjusts, but persistent discomfort should be monitored. Individual tolerance varies based on metabolic factors and the specific dosage form.
Interactions and health factors
This ingredient can interfere with other medications, particularly those containing opioids such as pain relief preparations or cough suppressants. It is essential to ensure a clear washout period from opioid-based substances before starting treatment. Product labelling and verified clinical sources remain the correct references for specific contraindications, interactions and reactions.
Further reading
What is naltrexone used for?
Naltrexone is mainly used as part of a broader therapeutic approach for alcohol dependence and opioid dependence. Certain combinations containing it are also used for weight management alongside a structured diet and exercise plan.
How does naltrexone work?
Naltrexone is an opioid antagonist that binds to opioid receptors in the brain and occupies these sites so other opioid substances cannot trigger the same chemical response. This blunts the usual reward response and reduces cravings for alcohol or opioids, and for weight control it influences appetite regulation pathways in the central nervous system.
How long does naltrexone take to work?
Naltrexone acts as a competitive opioid receptor antagonist, binding to brain opioid receptors to block the euphoric effects of opioids and alcohol, and starts to work within 1 hour. Its effect lasts 24 hours.
What are the side effects of naltrexone?
Common reactions can include nausea, headache, dizziness, or sleep disturbances during the initial phase of treatment, and these effects often settle as the body adjusts. Insomnia, anxiety and abdominal pain are also listed, while hepatotoxicity and depression are serious effects requiring immediate medical attention. Speak to a doctor or pharmacist if you are concerned about any reaction.
Can naltrexone be taken with other medicines?
Naltrexone can interfere with other medications, particularly those containing opioids such as pain relief preparations or cough suppressants. A clear washout period from opioid based substances is needed before starting treatment, so check with a doctor or pharmacist about your medicines.
Who should not take naltrexone?
Naltrexone is contraindicated in acute hepatitis, liver failure, current opioid dependence and in people with a positive urine screen for opioids. Individuals with liver or kidney health factors require monitoring, so discuss your health conditions with a clinical provider.
In which products can I find naltrexone?
Products containing naltrexone include Revia and Contrave. Compare forms, strengths and packs in the listings above.
Which brands contain naltrexone?
Besides the products listed here, naltrexone is sold under brand names such as Adepend and Mysimba. Names differ from country to country, so the active ingredient is the surest way to compare.
Can I buy naltrexone over the counter in Thailand?
Yes, online. Yasabai does not ask for a prescription to order naltrexone. We are an online store, not a dispensing pharmacy; we arrange your order and delivery on your behalf.
Ordering without a prescription →Where can I buy naltrexone online?
Our pharmacy partners ship from India to Thailand and across Asia in discreet packaging. Standard Airmail takes up to 3 weeks; Express Tracked Courier takes up to 1 week.
How ordering works →Related articles
26 Jul 2026 ⋅ 9 min read
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