Naloxone HCl

    WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 329670

CAS#: 357-08-4 (HCl)

Description: Naloxone is a μ-opioid receptor (MOR) inverse agonist. Naloxone has an extremely high affinity for μ-opioid receptors in the central nervous system (CNS). Its rapid blockade of those receptors often produces rapid onset of withdrawal symptoms. Naloxone also has an antagonist action, though with a lower affinity, at κ- (KOR) and δ-opioid receptors (DOR). The mechanism of action is not completely understood, but studies suggest it functions to produce withdrawal symptoms by competing for opiate receptor sites within the CNS (a competitive antagonist, not a direct agonist), thereby preventing the action of both endogenous and xenobiotic opiates on these receptors without directly producing any effects itself. Naloxone was approved for opioid overdose by the Food and Drug Administration in 1971

Price and Availability


USD 160
USD 1350

USD 350
USD 2450

USD 650
USD 3850

Naloxone HCl, purity > 98%, is in stock. Current shipping out time is about 2 weeks after order is received. CoA, QC data and MSDS documents are available in one week after order is received.

Chemical Structure


Theoretical Analysis

MedKoo Cat#: 329670
Name: Naloxone HCl
CAS#: 357-08-4 (HCl)
Chemical Formula: C19H22ClNO4
Exact Mass:
Molecular Weight: 363.838
Elemental Analysis: C, 62.72; H, 6.10; Cl, 9.74; N, 3.85; O, 17.59

Related CAS #: 465-65-6 (free base)   357-08-4 (HCl)   51481-60-8 (HCl dihydrate)    

Synonym: Naloxone HCl; EN-15304; EN15304; EN 15304; NIH7890; Naloxone hydrochloride; Narcan; Narcanti; Nalonee;

IUPAC/Chemical Name: (4R,4aS,7aR,12bS)-3-allyl-4a,9-dihydroxy-2,3,4,4a,5,6-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-7(7aH)-one hydrochloride


InChi Code: InChI=1S/C19H21NO4.ClH/c1-2-8-20-9-7-18-15-11-3-4-12(21)16(15)24-17(18)13(22)5-6-19(18,23)14(20)10-11;/h2-4,14,17,21,23H,1,5-10H2;1H/t14-,17+,18+,19-;/m1./s1

SMILES Code: O=C1[C@@](OC2=C(O)C=CC3=C24)([H])[C@@]54CCN(CC=C)[C@@](C3)([H])[C@]5(O)CC1.[H]Cl

Technical Data

Solid powder

>98% (or refer to the Certificate of Analysis)

Shipping Condition:
Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition:
Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Soluble in DMSO

Shelf Life:
>2 years if stored properly

Drug Formulation:
This drug may be formulated in DMSO

Stock Solution Storage:
0 - 4 C for short term (days to weeks), or -20 C for long term (months).

Harmonized System Code:

Additional Information

Naloxone was patented in 1961 and approved for opioid overdose by the Food and Drug Administration in 1971. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Naloxone is available as a generic medication. Its wholesale price in the developing world is between US$0.50 and 5.30 per dose. The vials of medication are not very expensive (less than 25 USD) in the United States. The price for a package of two auto-injectors in the US, however, has increased from $690 in 2014 to $4,500 in 2016.

The Ki affinity values of (−)-naloxone for the MOR, KOR, and DOR have been reported as 0.559 nM, 4.91 nM, and 36.5 nM, respectively, whereas for (+)-naloxone, 3,550 nM, 8,950 nM, and 122,000 nM, respectively, have been reported. As such, (−)-naloxone appears to be the active isomer. Moreover, these data suggest that naloxone binds to the MOR with approximately 9-fold greater affinity relative to the KOR and around 60-fold greater affinity relative to the DOR.