Synephrine HCl

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

MedKoo CAT#: 329869

CAS#: 5985-28-4 (HCl)

Description: Synephrine, or, more specifically, p-synephrine, is an alkaloid, occurring naturally in some plants and animals, and also in approved drugs products as its m-substituted analog known as neo-synephrine. p-Synephrine and m-synephrine are known for their longer acting adrenergic effects compared to norepinephrine. This substance is present at very low concentrations in common foodstuffs such as orange juice and other orange (Citrus species) products, both of the "sweet" and "bitter" variety.

Chemical Structure

Synephrine HCl
CAS# 5985-28-4 (HCl)

Theoretical Analysis

MedKoo Cat#: 329869
Name: Synephrine HCl
CAS#: 5985-28-4 (HCl)
Chemical Formula: C9H14ClNO2
Exact Mass: 203.0713
Molecular Weight: 203.666
Elemental Analysis: C, 53.08; H, 6.93; Cl, 17.41; N, 6.88; O, 15.71

Price and Availability

Size Price Availability Quantity
5.0g USD 225.0 2 Weeks
10.0g USD 370.0 2 Weeks
25.0g USD 575.0 2 Weeks
50.0g USD 750.0 2 Weeks
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Related CAS #: 5985-28-4 (HCl)   16589-24-5 (tartrate)   94-07-5 (racemate)   614-35-7 (R-isomer)    

Synonym: Synephrine HCl; Sympatol; oxedrine;

IUPAC/Chemical Name: 4-Hydroxy-alpha-((methylamino)methyl)benzyl alcohol hydrochloride


InChi Code: InChI=1S/C9H13NO2.ClH/c1-10-6-9(12)7-2-4-8(11)5-3-7;/h2-5,9-12H,6H2,1H3;1H


Appearance: Solid powder

Purity: >95% (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).

Solubility: 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).

HS Tariff Code: 2934.99.9001

Preparing Stock Solutions

The following data is based on the product molecular weight 203.666 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1: Ratamess NA, Bush JA, Kang J, Kraemer WJ, Stohs SJ, Nocera VG, Leise MD, Diamond KB, Faigenbaum AD. The effects of supplementation with P-Synephrine alone and in combination with caffeine on resistance exercise performance. J Int Soc Sports Nutr. 2015 Sep 17;12:35. doi: 10.1186/s12970-015-0096-5. eCollection 2015. PubMed PMID: 26388707; PubMed Central PMCID: PMC4573476.

2: Gutiérrez-Hellín J, Salinero JJ, Abían-Vicen J, Areces F, Lara B, Gallo C, Puente C, Del Coso J. Acute consumption of p-synephrine does not enhance performance in sprint athletes. Appl Physiol Nutr Metab. 2016 Jan;41(1):63-9. doi: 10.1139/apnm-2015-0299. Epub 2015 Oct 6. PubMed PMID: 26673246.

3: Stohs SJ, Preuss HG, Keith SC, Keith PL, Miller H, Kaats GR. Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes. Int J Med Sci. 2011 Apr 28;8(4):295-301. PubMed PMID: 21537493; PubMed Central PMCID: PMC3085176.

4: Shara M, Stohs SJ, Mukattash TL. Cardiovascular Safety of Oral p-Synephrine (Bitter Orange) in Healthy Subjects: A Randomized Placebo-Controlled Cross-over Clinical Trial. Phytother Res. 2016 May;30(5):842-7. doi: 10.1002/ptr.5590. Epub 2016 Mar 7. PubMed PMID: 26948284.

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14: Bui LT, Nguyen DT, Ambrose PJ. Blood pressure and heart rate effects following a single dose of bitter orange. Ann Pharmacother. 2006 Jan;40(1):53-7. Epub 2005 Nov 29. PubMed PMID: 16317106.

15: Nguyen DT, Bui LT, Ambrose PJ. Response of CEDIA amphetamines assay after a single dose of bitter orange. Ther Drug Monit. 2006 Apr;28(2):252-4. PubMed PMID: 16628139.

16: Min B, Cios D, Kluger J, White CM. Absence of QTc-interval-prolonging or hemodynamic effects of a single dose of bitter-orange extract in healthy subjects. Pharmacotherapy. 2005 Dec;25(12):1719-24. PubMed PMID: 16305290.

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Additional Information

The preparations used in traditional Chinese medicine (TCM), also known as Zhi Shi, are the immature and dried whole oranges from Citrus aurantium (Fructus Aurantii Immaturus). Extracts of the same material or purified synephrine are also marketed in the US, sometimes in combination with caffeine, as a weight-loss-promoting dietary supplement for oral consumption. While the traditional preparations have been in use for millennia as a component of TCM-formulas, synephrine itself is not an approved OTC drug. As a pharmaceutical, m-synephrine is still used as a sympathomimetic (i.e. for its hypertensive and vasoconstrictor properties), mostly by injection for the treatment of emergencies such as shock, and rarely orally for the treatment of bronchial problems associated with asthma and hay-fever.