Nalmefene
Nalmefene (CAS: 55096-26-9), with the molecular formula C21H25NO3 and a molecular weight of 339.43 g/mol, is a potent opioid antagonist. It functions by blocking the effects of opioids at the receptor level. This compound is primarily recognised for its therapeutic applications in managing opioid overdose and in the treatment of alcohol dependence, acting as a critical tool in addiction medicine and emergency response.
- IUPAC
- (5α)-17-(Cyclopropylmethyl)-4,5-epoxy-6-methylenemorphinan-3,14-diol

Opioid Antagonist Therapy
Nalmefene is clinically used to reverse the effects of opioid overdose, restoring normal respiration. It is also employed in the management of alcohol dependence by reducing cravings and relapse rates.
Research and Development
As a selective opioid receptor antagonist, Nalmefene serves as a valuable research tool in neurobiology and pharmacology to study opioid receptor function and related signaling pathways.
Biochemical Studies
This compound is utilized in biochemical assays and studies involving GPCR modulators, particularly those targeting opioid receptors within cell signaling pathways.
| Molecular weight | 339.43 |
|---|---|
| Empirical formula | C21H25NO3 |
| Storage temperature | 2-8°C |

Hazard statements
- H315Causes skin irritation
- H319Causes serious eye irritation
- H335May cause respiratory irritation
Precautionary statements
- P261Avoid breathing dust, fume, gas or vapours
- P305IF IN EYES
| Protective equipment | dust mask type N95 (US), Eyeshields, Gloves |
|---|---|
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | Xi |
| Risk statements (R) | 36/37/38 |
| Safety statements (S) | 26-36 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
| Gene Information | rat ... Oprd1(24613), Oprm1(25601) |
|---|
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is Nalmefene used for?
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Nalmefene is used for the treatment of alcohol dependence and opioid overdose.
What is the CAS number and formula for Nalmefene?
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The CAS number for Nalmefene is 55096-26-9, and its molecular formula is C21H25NO3.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies Nalmefene with a molecular weight of 339.43 g/mol. We do not specify USP, BP, or EP grades unless explicitly stated in the product data. For detailed purity information, please refer to the product specifications.
How should Nalmefene be handled safely?
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Nalmefene is classified with GHS07 and a 'Warning' signal word, with hazard statements H315, H319, and H335. It requires personal protective equipment including a dust mask (N95), eyeshields, and gloves. Handle in a well-ventilated area and avoid dust formation.
How is Nalmefene packed and shipped?
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Nalmefene is typically stored at 2-8°C. Tech Serve Solutions exports fine chemicals globally, adhering to all necessary shipping regulations for laboratory reagents and pharmaceutical intermediates.
How can I request a sample or quote for Nalmefene?
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To request a sample or a quote for Nalmefene, please contact our sales team through the website or call us directly.
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