Ephedrine

Ephedrine	Last updated: 16/09/2025
(Also known as: (-)-(1R,2S)-ephedrine; L-(-)-ephedrine )

GENERAL INFORMATION

Description

A veterinary and human drug used to contrict blood vessels and widen bronchial passages. It is often formulated using the hydrochloride salt.

Examples of veterinary uses

Used to relieve breathing and/or urinary difficulties

Examples of species treated

Dogs; Cats

Approval status

VMR 2013/2033 approval status (GB/UK)

Approved - usually supplied as a prescription only medicine to be authorised by a veterinarian (POM-V)

EU Regulatory approval status

Approved

Chemical structure

Isomerism

Ephedrine exhibits stereoisomerism due to the presence of two chiral centres in its molecular structure, specifically at the carbon atoms bearing the hydroxyl and amino groups. This configuration allows for the existence of four stereoisomers: (1R,2S)-(-)-ephedrine, (1S,2R)-(+)-ephedrine, (1R,2R)-(-)-pseudoephedrine, and (1S,2S)-(+)-pseudoephedrine. (1R,2S)-(-)-ephedrine is the most biologically active.

Chemical formula

C₁₀H₁₅NO

Canonical SMILES

CC(C(C1=CC=CC=C1)O)NC

Isomeric SMILES

C[C@@H]([C@@H](C1=CC=CC=C1)O)NC

International Chemical Identifier key (InChIKey)

KWGRBVOPPLSCSI-WPRPVWTQSA-N

International Chemical Identifier (InChI)

InChI=1S/C10H15NO/c1-8(11-2)10(12)9-6-4-3-5-7-9/h3-8,10-12H,1-2H3/t8-,10-/m0/s1

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
ephedrine	-
ephidrine hydrochloride	Variant

General status

Veterinary substance type

Medicinal drug: Nervous system stimulant, Bronchodilator agent

Substance groups

Sympathomimetic amine; Plant-derived substance

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Indirect stimulation of the adrenergic receptor system by increasing the activity of norepinephrine at the postsynaptic a- and ß-receptors.

Molecular targets

[Sodium-dependent noradrenaline transporter, Inverse agonist], [Alpha-1A adrenergic receptor, Unknown activity], [Synaptic vesicular amine transporter, Inhibitor]

CAS RN

299-42-3

Alternative/old CAS RN

321-98-2; 4607-45-8; 90-81-3

EC number

202-017-0

CIPAC number

US EPA chemical code

PubChem CID

9294

Therapeutic Class

Urologicals: Other urologicals

ATCvet Code

QG04BX90

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

165.23

PIN (Preferred Identification Name)

(1R,2S)-2-(methylamino)-1-phenyl-1-propanol

IUPAC name

(1R,2S)-2-(methylamino)-1-phenyl-1-propanol

CAS name

(-)-a-(1-methylaminoethyl)benzyl alcohol

Forever chemical

Other status information

Ephedrine may interact with other sympathomimetics.

Relevant Environmental Water Quality Standards

Physical state

Crystalline solid

Related substances & organisms

ephedrine hydrochloride

Commercial

Property

Value

Availability status

Current

Introduction & key dates

Ancient use in traditional Chinese medicine as plant extract; 1885, chemical isolation; 1920s, synthetic prduction started; Mid 20th century, vet use introduced

Example manufacturers & suppliers of products using this active now or historically

Ecuphar NV

Example products using this active

Enurace Tablets

Formulation and application details

Available in tablet form

Commercial production

The production of ephedrine can follow either natural extraction or synthetic pathways. Traditionally, it is extracted from Ephedra plants, where the dried and ground plant material is soaked in solvents like ethanol or methanol to dissolve the alkaloids. The solution is then filtered and purified to isolate ephedrine. In synthetic methods, a common route involves a Friedel–Crafts reaction using precursors like 2-chloropropionyl chloride and benzene, catalysed by a Lewis acid to form an intermediate, which is then reacted with methylamine to yield ephedrine or pseudoephedrine

Impact on climate of production and use

Published GHG data is not available for ephedrine. However, the GHG emissions during its production will depend on the method used. If extracted from plants emissions are likely to be low and typically between 1.0 and 4.0 kg CO₂e per kg of product, If synthesised, emissions are likely to be significantly higher, possibly between 10 to 100 kg CO₂e per kg product depending on solvent recovery, and energy sources used.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C (mg l⁻¹)

63600

High

Solubility - In organic solvents at 20 °C (mg l⁻¹)

Melting point (°C)

Boiling point (°C)

255

Degradation point (°C)

Flashpoint (°C)

Octanol-water partition coefficient at pH 7, 20 °C

1.35 X 10⁰¹

Calculated

Log P

1.13

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

10.25

Vapour pressure at 20 °C (mPa)

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Surface tension (mN m⁻¹)

Refractive Index

Environmental release

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7

Value

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Sediment phase only DT₅₀ (days)

Air degradation

As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.

Decay in stored produce DT₅₀

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

600

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

562

Unknown species

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (g ha⁻¹)

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Chronic

Notes

Bumblebees (Bombus spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Mason bees (Osmia spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Other bee species (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other bee species (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Beneficial insects (Ladybirds)

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps)

Beneficial insects (Predatory mites)

Beneficial insects (Ground beetles)

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

Aquatic Plants (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹)

Algae - Chronic (growth rate, fresh; mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

600

Rat

Moderate

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Subcutaneous LD₅₀ = 300 mg kg⁻¹

Rat

Intravenous LDLo = 150 mg kg⁻¹

Rat

ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)

ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Occupational

Mammalian dose elimination route and rate

Renally eliminated mostly as unchanged drug

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

No data found

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

May invoke weight loss & nausea
Possible CNS toxicant
May cause flushing, sweating & acne vulgaris

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

ephedrine

French

German

Danish

Italian

Spanish

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	16/09/2025
Contact:	aeru@herts.ac.uk
Please cite as:	Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242