Cat. No.: HY-17417A

Naloxone

8 Cited Publications

Customer Review

Based on 8 publication(s) in Google Scholar

Naloxone is an orally active opioid receptor antagonist. Naloxone attenuates spinal cord stimulation‑associated anti‑hyperalgesic effects, antagonizes physiologic effects of endogenous opioid peptides linked to central nervous system injury sequelae, functions as a pressor agent to induce modest elevations in mean arterial blood pressure, exerts neuroprotective effects to improve post‑traumatic neurologic motor function, blocks opioid receptor‑mediated amnesic pathways, enhances memory consolidation, reverses ACTH‑ and epinephrine‑induced amnesia, and potentiates the memory‑facilitatory effects of ACTH and epinephrine.

For research use only. We do not sell to patients.

Purity: 99.71%
CAS No.: 465-65-6
Formula: C₁₉H₂₁NO₄
Molecular Weight:327.37

Storage:

4°C, protect from light, stored under nitrogen

* In solvent : -80°C, 6 months; -20°C, 1 month (protect from light, stored under nitrogen)

Naloxone Chemical Structure

CAS No.: 465-65-6

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Fluorescent Dye

Strong Fluorescence Signal / Multi-Disciplinary Applications / High Fluorescence Specificity

Biological Activity
- Description
- Cellular Effect
- In Vitro
- In Vivo
Chemical Information
Publications (8)
Solvent & Solubility
- In Vitro
- In Vivo
Purity & Documentation
References
Help & FAQs
Classifications
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Biological Activity

Description

All Opioid Receptor Isoforms :

Cellular Effect

Cell Line	Type	Value	Description	References
CHO	EC₅₀	10 nM Compound: 4	Agonist activity at human opioid kappa receptor expressed in CHO cells assessed as stimulation of [35S]GTPgammaS binding Agonist activity at human opioid kappa receptor expressed in CHO cells assessed as stimulation of [35S]GTPgammaS binding	[PMID: 17407276]
CHO	IC₅₀	146 nM Compound: Naloxone	Antagonist activity at human delta opioid receptor expressed in CHO cell membranes assessed as reduction in SNC80-induced [35S]GTPgammaS binding incubated for 1 hr Antagonist activity at human delta opioid receptor expressed in CHO cell membranes assessed as reduction in SNC80-induced [35S]GTPgammaS binding incubated for 1 hr	[PMID: 30996778]
CHO	IC₅₀	15.37 nM Compound: 3; NLX	Antagonist activity at mouse mu opioid receptor expressed in CHO cells cotransfected with Galphaqi5 assessed as inhibition of DAMGO-induced increase in intracellular calcium concentration preincubated for 60 mins in Fluo4AM solution followed by compound a Antagonist activity at mouse mu opioid receptor expressed in CHO cells cotransfected with Galphaqi5 assessed as inhibition of DAMGO-induced increase in intracellular calcium concentration preincubated for 60 mins in Fluo4AM solution followed by compound a	[PMID: 31782922]
CHO	IC₅₀	153 nM Compound: Naloxone	Antagonist activity at human delta opioid receptor expressed in CHO cell membranes assessed as reduction in SNC80-induced [35S]GTPgammaS binding preincubated for 5 mins followed by SNC80 addition and measured after 1 hr Antagonist activity at human delta opioid receptor expressed in CHO cell membranes assessed as reduction in SNC80-induced [35S]GTPgammaS binding preincubated for 5 mins followed by SNC80 addition and measured after 1 hr	[PMID: 32530286]
CHO	IC₅₀	23 nM Compound: 4	Agonist activity at human opioid gamma receptor expressed in CHO cells assessed as inhibition of DAGO-stimulated [35S]GTPgammaS binding Agonist activity at human opioid gamma receptor expressed in CHO cells assessed as inhibition of DAGO-stimulated [35S]GTPgammaS binding	[PMID: 17407276]
CHO	IC₅₀	320 nM Compound: 4	Antagonist activity at human opioid kappa receptor expressed in CHO cells assessed as inhibition of U-50488-stimulated [35S]GTP-gamma-S binding Antagonist activity at human opioid kappa receptor expressed in CHO cells assessed as inhibition of U-50488-stimulated [35S]GTP-gamma-S binding	[PMID: 17407276]
CHO	IC₅₀	7.3 nM Compound: 1a	Antagonist activity assessed as inhibition of loperamide-stimulated [35S]GTPgammaS binding to human mu opioid receptor expressed in CHO cells Antagonist activity assessed as inhibition of loperamide-stimulated [35S]GTPgammaS binding to human mu opioid receptor expressed in CHO cells	[PMID: 17149859]
CHO	IC₅₀	7.3 nM Compound: 2a	Antagonist activity against human cloned mu opioid receptor expressed in CHO cells assessed as inhibition of loperamide-stimulated [35S]GTP-gamma-S binding Antagonist activity against human cloned mu opioid receptor expressed in CHO cells assessed as inhibition of loperamide-stimulated [35S]GTP-gamma-S binding	[PMID: 17149858]
CHO	IC₅₀	78.2 nM Compound: Naloxone	Antagonist activity at human DOR expressed in CHO cell membranes assessed as reduction in SNC80-induced response incubated for 1 hr by [35S]-GTPgammaS coupling assay Antagonist activity at human DOR expressed in CHO cell membranes assessed as reduction in SNC80-induced response incubated for 1 hr by [35S]-GTPgammaS coupling assay	[PMID: 31834798]
HEK293	IC₅₀	138 nM Compound: naloxone	Displacement of [125I]deltorphin 2 from human recombinant delta opioid receptor expressed in HEK293 cells Displacement of [125I]deltorphin 2 from human recombinant delta opioid receptor expressed in HEK293 cells	[PMID: 16989522]
HEK293	IC₅₀	138 nM Compound: naloxone	Displacement of [125I]deltorphin 2 from human recombinant delta opioid receptor expressed in HEK cell membrane Displacement of [125I]deltorphin 2 from human recombinant delta opioid receptor expressed in HEK cell membrane	[PMID: 17388627]
HEK293	IC₅₀	138 nM Compound: naloxone	Displacement of [125I]deltorphin 2 from human recombinant delta opioid receptor expressed in HEK cell membranes Displacement of [125I]deltorphin 2 from human recombinant delta opioid receptor expressed in HEK cell membranes	[PMID: 17451272]
HEK293	IC₅₀	138 nM Compound: naloxone	Displacement of [125I]deltorphin 2 from human recombinant delta opioid receptor expressed in HEK cells Displacement of [125I]deltorphin 2 from human recombinant delta opioid receptor expressed in HEK cells	[PMID: 18039010]
HEK-293T	IC₅₀	0.045 μM Compound: Naloxone	Antagonist activity at recombinant human MOR expressed in HEK293T cells assessed as reduction in DAMGO-induced inhibition of forskolin-stimulated cAMP level preincubated for 15 to 20 mins followed by DAMGO and forskolin addition by GloSensor assay Antagonist activity at recombinant human MOR expressed in HEK293T cells assessed as reduction in DAMGO-induced inhibition of forskolin-stimulated cAMP level preincubated for 15 to 20 mins followed by DAMGO and forskolin addition by GloSensor assay	[PMID: 28726402]

In Vitro

Naloxone (800 µg per tablet; 2 h annealing, 5 days freeze drying) forms freeze-dried buccal tablets that form a stable amorphous matrix that remains chemically and physically intact for 9 months at 4°C or 25°C^[4].
Naloxone (800 µg per tablet; up to 30 s) forms freeze-dried buccal tablets that achieve 90% disintegration in 4.8 seconds under buccal-relevant conditions (37°C, 0.7 mL phosphate buffer) and fully disintegrate within 30 s across all tested temperature and medium volume conditions^[4].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

In Vivo

Naloxone (10 mg/kg; i.p.; single dose) significantly inhibits the early SCS-induced reversal of neuropathic mechanical hypersensitivity in male Sprague Dawley rats, but has no effect on the incremental anti-hyperalgesic effect of late SCS^[1].
Naloxone (2.0 mg/kg; 1.7 mg/kg/h; i.v.; bolus over 60 seconds followed by constant infusion; 4 hours) significantly improves long-term neurologic motor recovery up to 4 weeks following moderate fluid-percussion traumatic brain injury in male Sprague-Dawley rats, with a median composite neurologic score of 18.5 at week 4^[2].
Naloxone (0.4 mg/kg; i.p.; single immediate post-training injection) produces significant memory facilitation in male Wistar rats trained on task 1 and 2, and reverses the amnesic effects of post-training ACTH and epinephrine administration^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Animal Model:

Sprague Dawley (adult male, 200-250 g, neuropathic pain model via partial sciatic nerve ligation and epidural monopolar electrode implantation at spinal segments T12/13)^[1]
Dosage:

10 mg/kg
Administration:

i.p.; single dose
Result:

Decreased the ipsilateral:contralateral paw withdrawal threshold ratio after SCS1.
Exerted no discernible effect on the anti-hyperalgesic effect induced by SCS2.

Animal Model:

Sprague-Dawley (male, moderate severity lateral fluid-percussion traumatic brain injury induced via 2.4 to 2.5 atmosphere pressure pulse)^[2]
Dosage:

2.0 mg/kg (bolus); 1.7 mg/kg/h (infusion)
Administration:

i.v.; bolus over 60 seconds followed by constant infusion; 4 hours
Result:

Caused a modest, nonsignificant increase in mean arterial blood pressure during 4-hour postinjury monitoring period.
Showed no significant changes to arterial blood gases, pH, or brain temperature.
Exhibited no significant improvement in composite neurologic motor scores at 24 hours postinjury.
Achieved a significant improvement in median composite neurologic motor scores at 1 week postinjury.
Reached a median composite neurologic motor score of 18.5 out of maximum 20 by week 4.
Resulted in 100% survival rate over the 4-week study period.

Animal Model:

Wistar rats (male, age 51-69 days, weight 140-200 g, step-down inhibitory avoidance task 1 training)^[3]
Dosage:

0.4 mg/kg
Administration:

i.p.; single immediate post-training injection
Result:

Produced a median (mean) training-test step-down latency difference of 180.00 sec.
Produced a median (mean) training-test step-down latency difference of 180.00 (144.45) sec when co-administered with 2.0 μg/kg ACTH_1-24, reversing the amnesic effect of ACTH alone and showing a significant difference from naloxone alone.
Produced a median (mean) training-test step-down latency difference of 180.00 (134.98) sec when co-administered with 50.0 μg/kg epinephrine HC1, reversing the amnesic effect of epinephrine alone and showing a significant difference from naloxone alone.

Animal Model:

Wistar rats (male, age 51-69 days, weight 140-200 g, step-down inhibitory avoidance task 2 training)^[3]
Dosage:

0.4 mg/kg
Administration:

i.p.; single immediate post-training injection
Result:

Produced a median (mean) training-test step-down latency difference of 24.13 (56.18) sec, showing significant memory facilitation compared to saline controls.
Produced a median (mean) training-test step-down latency difference of 105.07 (113.65) sec when co-administered with 2.0 μg/kg ACTH_1-24, potentiating the facilitatory effect of ACTH alone and showing a significant difference from naloxone alone .
Produced a median (mean) training-test step-down latency difference of 81.85 (96.86) sec when co-administered with 50.0 μg/kg epinephrine HC1, potentiating the facilitatory effect of epinephrine alone and showing a significant difference from naloxone alone.

Chemical Information

CAS No. 465-65-6
Appearance Solid
Molecular Weight 327.37
Formula C₁₉H₂₁NO₄
Color White to off-white
SMILES

OC1=C(O2)C([C@]([C@]2([H])C(CC3)=O)(CCN4CC=C)[C@]3(O)[C@H]4C5)=C5C=C1
Shipping

Room temperature in continental US; may vary elsewhere.
Storage

4°C, protect from light, stored under nitrogen

* In solvent : -80°C, 6 months; -20°C, 1 month (protect from light, stored under nitrogen)

Publications (8)

All OthersCell Proliferation/Viability Assay

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Journal Impact Factor

Nature

Structural snapshots capture nucleotide release at the μ-opioid receptor. [Abstract]

2025 Dec;648(8094):755-763. PMID: 41193810
Nat Methods

Single-molecule localization and diffusivity microscopy reveals dynamic biomolecular organization in living cells. [Abstract]

2026 May;23(5):1011-1023. PMID: 42050111
Nat Commun

Neuropeptide Y neurons mediate opioid-induced itch by disinhibiting GRP-GRPR microcircuits in the spinal cord. [Abstract]

2025 Aug 1;16(1):7074. PMID: 40750771

Naloxone purchased from MedChemExpress. Usage Cited in: Nat Commun. 2025 Aug 1;16(1):7074. [Abstract]

Heatmaps shows the calcium signals within the 10-25 min after drugs injection (i.t., 0.3 nmol Morphine, 10 nmol Naloxone + 0.3 nmol Morphine, and 10 μg NPY + 0.3 nmol Morphine), n = 5 mice per group.
Cell Rep

Morphine and Naloxone Facilitate Neural Stem Cells Proliferation via a TET1-Dependent and Receptor-Independent Pathway. [Abstract]

2020 Mar 17;30(11):3625-3631.e6. PMID: 32187535

Naloxone purchased from MedChemExpress. Usage Cited in: Cell Rep. 2020 Mar 17;30(11):3625-3631.e6. [Abstract]

NSCs were treated with different concentrations of Naloxone, Morphine, Naloxone and Morphine (Mor+Nal, 1:1), or Nal-M. Cell numbers were determined on day 3.

Naloxone purchased from MedChemExpress. Usage Cited in: Cell Rep. 2020 Mar 17;30(11):3625-3631.e6. [Abstract]

Neural stem cells (NSCs) were treated with 1 μM Naloxone or Morphine. The contents of 5mC and 5hmC in NSCs (day 3) were determined by high-spot Western blot assay.
Br J Pharmacol

Semax peptide targets the μ opioid receptor gene Oprm1 to promote deubiquitination and functional recovery after spinal cord injury in female mice. [Abstract]

2025 Jul 21. PMID: 40692165
J Med Chem

2026 Mar 5;69(6):6508-6527.
Eur J Pain

Endocannabinoid activation of CB1 receptors contributes to long-lasting reversal of neuropathic pain by repetitive spinal cord stimulation. [Abstract]

2017 May;21(5):804-814. PMID: 28107590

Naloxone purchased from MedChemExpress. Usage Cited in: Eur J Pain. 2017 May;21(5):804-814. [Abstract]

The SCS1 (early SCS)-mediated increase in the ipsilateral:contralateral PWT ratio (compared to pre-SCS) is significantly reduced by the opioid receptor antagonist, Naloxone, which is administered 10 min before SCS1.
bioRxiv

2026 Jun 3.

Solvent & Solubility

In Vitro:

DMSO : 100 mg/mL (305.46 mM; Need ultrasonic; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

View the Complete Stock Solution Preparation Table

Preparing Stock Solutions

View the Complete Stock Solution Preparation Table

Concentration Solvent Mass

1 mg

5 mg

10 mg

Concentration

Solvent

Mass

1 mM

3.0546 mL

15.2732 mL

30.5465 mL

5 mM

0.6109 mL

3.0546 mL

6.1093 mL

10 mM

0.3055 mL

1.5273 mL

3.0546 mL

Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.

Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (protect from light, stored under nitrogen). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

Molarity Calculator

Mass (g) = Concentration (mol/L) × Volume (L) × Molecular Weight (g/mol)

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Molecular Weight Molecular Weight

Dilution Calculator

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In Vivo:

Select the appropriate dissolution method based on your experimental animal and administration route.

Stock Solution Working Solution

For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for In Vivo experiments, it is recommended to prepare freshly and use it on the same day.
The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 10% DMSO 40% PEG300 5% Tween-80 45% Saline

Solubility: ≥ 5 mg/mL (15.27 mM); Clear solution

This protocol yields a clear solution of ≥ 5 mg/mL (saturation unknown).

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (50.0 mg/mL) to 400 μL PEG300, and mix evenly; then add 50 μL Tween-80 and mix evenly; then add 450 μL Saline to adjust the volume to 1 mL.

Protocol 2

Add each solvent one by one: 10% DMSO 90% (20% SBE-β-CD in Saline)

Solubility: ≥ 5 mg/mL (15.27 mM); Clear solution

This protocol yields a clear solution of ≥ 5 mg/mL (saturation unknown).

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (50.0 mg/mL) to 900 μL 20% SBE-β-CD in Saline, and mix evenly.

Protocol 3

Add each solvent one by one: 10% DMSO 90% Corn Oil

Solubility: ≥ 5 mg/mL (15.27 mM); Clear solution

This protocol yields a clear solution of ≥ 5 mg/mL (saturation unknown). If the continuous dosing period exceeds half a month, please choose this protocol carefully.

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (50.0 mg/mL) to 900 μL Corn oil, and mix evenly.

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage Dosage
mg/kg
Animal Weight (Per Animal) Animal Weight (Per Animal)
g
Dosing Volume (Per Animal) Dosing Volume (Per Animal)
μL
Number of Animals Number of Animals

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Please enter your animal formula composition:

%
DMSO +

Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.
%
+
+
%
Tween-80 + +
%
Saline +

The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).

Working solution concentration: 0.22 mg/mL

Purity & Documentation

Select Batch:

Purity: 99.98%

Assay: 99.98%

ee.: 99.98%

Data Sheet (308 KB)
SDS (392 KB)
- English - EN (392 KB)
- Français - FR (392 KB)
- Deutsch - DE (392 KB)
- Norwegian - NO (392 KB)
- Español - ES (392 KB)
- Swedish - SV (392 KB)
- Italian - IT (392 KB)
- Korean - KR (392 KB)
- Portuguese - PT (392 KB)
COA (2659 KB)
Elemental Analysis Report (2659 KB)
HNMR (2659 KB)
CNMR (2659 KB)
RP-HPLC (2659 KB)
NP-HPLC (2659 KB)
MS (2659 KB)
LCMS (2659 KB)
IR (2659 KB)
GC (2659 KB)
OR (2659 KB)
SDS-PAGE (2659 KB)
SEC-HPLC (2659 KB)
Other Report (2659 KB)
Handling Instructions (2659 KB)

References

[1]. Sun L, et al. Endocannabinoid activation of CB receptors contributes to long-lasting reversal of neuropathic pain by repetitive spinal cord stimulation. European journal of pain (London, England). 2017 May;21(5):804-814. [Content Brief]

[2]. McIntosh TK, et al. Beneficial effect of the nonselective opiate antagonist naloxone hydrochloride and the thyrotropin-releasing hormone (TRH) analog YM-14673 on long-term neurobehavioral outcome following experimental brain injury in the rat. J Neurotrauma. 1993 Winter;10(4):373-84.
[Content Brief]

[3]. Izquierdo I, et al. Effect of ACTH, epinephrine, beta-endorphin, naloxone, and of the combination of naloxone or beta-endorphin with ACTH or epinephrine on memory consolidation. Psychoneuroendocrinology. 1983;8(1):81-7. [Content Brief]

[4]. Alqurshi A, et al. Amorphous Formulation and in Vitro Performance Testing of Instantly Disintegrating Buccal Tablets for the Emergency Delivery of Naloxone. Molecular pharmaceutics. 2016 May 02;13(5):1688-98.

Help & FAQs

How should lyophilized recombinant proteins be reconstituted and stored?

1. Before opening the cap, centrifuge the vial at 13000 rpm for 20-30 seconds. This step will ensure that any lyophilized powder that may have adhered to the cap or walls is collected at the bottom of the vial, minimizing the risk of product loss.

Complete Stock Solution Preparation Table

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg
DMSO	1 mM	3.0546 mL	15.2732 mL	30.5465 mL	76.3662 mL
	5 mM	0.6109 mL	3.0546 mL	6.1093 mL	15.2732 mL
	10 mM	0.3055 mL	1.5273 mL	3.0546 mL	7.6366 mL
	15 mM	0.2036 mL	1.0182 mL	2.0364 mL	5.0911 mL
	20 mM	0.1527 mL	0.7637 mL	1.5273 mL	3.8183 mL
	25 mM	0.1222 mL	0.6109 mL	1.2219 mL	3.0546 mL
	30 mM	0.1018 mL	0.5091 mL	1.0182 mL	2.5455 mL
	40 mM	0.0764 mL	0.3818 mL	0.7637 mL	1.9092 mL
	50 mM	0.0611 mL	0.3055 mL	0.6109 mL	1.5273 mL
	60 mM	0.0509 mL	0.2546 mL	0.5091 mL	1.2728 mL
	80 mM	0.0382 mL	0.1909 mL	0.3818 mL	0.9546 mL
	100 mM	0.0305 mL	0.1527 mL	0.3055 mL	0.7637 mL

Bioz

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Naloxone

DAMGO

Norbinaltorphimine dihydrochloride

nor-Binaltorphimine

Alprenolol

PRE-084 hydrochloride

Naloxone (Standard)

Publications Citing Use of MedChemExpress (MCE) Naloxone

All Opioid Receptor Isoforms

Biological Activity

Chemical Information

Publications (8)

Solvent & Solubility

Purity & Documentation

References

Help & FAQs

Complete Stock Solution Preparation Table

Bioz

Naloxone

DAMGO

Norbinaltorphimine dihydrochloride

nor-Binaltorphimine

Alprenolol

PRE-084 hydrochloride

Naloxone (Standard)

Publications Citing Use of MedChemExpress (MCE) Naloxone

All Opioid Receptor Isoforms

Biological Activity

Chemical Information

Publications (8)

Solvent & Solubility

Purity & Documentation

References

Help & FAQs

Complete Stock Solution Preparation Table

Naloxone Related Classifications

HY-17417A Related Classifications

Bioz