| Chemical structure |
Contains a β‑hydroxy and an α‑methyl substituent on the phenyl‑propylamine skeleton. It is a mixed agonist at α and β adrenergic receptors. |
Same core skeleton, but the β‑hydroxy group has a different orientation (the “pseudo” in the name). It is a stronger β‑adrenergic agonist and a weaker α agonist compared with ephedrine. |
| Pharmacological action |
Stimulates both α‑ and β‑adrenergic receptors → vasoconstriction, bronchodilation, CNS stimulation. |
Primarily β‑adrenergic → bronchodilation, vasodilation, mild CNS stimulation; less vasoconstrictive. |
| Primary medical uses |
• 3‑day “pre‑exercise” or “pre‑flight” “boost” (now largely discontinued).
• Severe asthma exacerbation (in combination with β‑agonists).
• Historically used as a decongestant, appetite suppressant, and weight‑loss agent (now banned in most foods). |
• Over‑the‑counter nasal decongestant (sinus & nasal congestion).
• Some cough syrups as an active ingredient. |
| Typical OTC availability |
Very limited; most countries restrict it to prescription‑only or ban it entirely (e.g., EU, Australia, Canada). |
Widely sold in pharmacies and supermarkets as “Pseudoephedrine” (often behind the counter; you may need to show ID). |
| Regulatory status |
Prescription‑only in the U.S.; “Schedule II” in many jurisdictions.
In the U.S., the FDA’s 2002 “Pseudoephedrine Act” restricts sales of both pseudoephedrine and ephedrine because of their use in illicit meth production. |
Prescription‑only in many U.S. states (after the 2005 “Act to Prevent the Manufacture of Methamphetamine”).
In other countries (e.g., UK) it remains OTC but is controlled under the Misuse of Drugs Act. |
| Side‑effect profile |
• Tachycardia, hypertension, palpitations, insomnia, tremor, agitation.
• Because of α‑agonist activity, more pronounced vasoconstriction (e.g., headaches, dizziness). |
• Similar but generally milder CNS effects (e.g., jitteriness).
• Less risk of severe hypertension or tachycardia. |
| Legal restrictions related to methamphetamine production |
Highly regulated: Ephedrine is a “precursor” listed in the U.S. Controlled Substances Act, and its purchase is limited by the 2002 act.
Internationally, the WHO’s 2012 “Schedule” lists it as a precursor for meth. |
Even more tightly controlled: Pseudoephedrine is the more common precursor; many countries impose quantity limits per purchase, require ID, or ban home‑grown production. |
| Availability for research |
Researchers can obtain ephedrine through a DEA schedule‑II license (U.S.) or an equivalent controlled‑substances license elsewhere. |
Similarly, pseudoephedrine is a controlled precursor; researchers must apply for a special license. |
| Why the difference matters |
Ephedrine’s stronger α‑activity makes it a better vasoconstrictor; it’s more potent as a bronchodilator when combined with β‑agonists. It also gives it stronger stimulant effects, which is why it was used in “pre‑exercise” supplements.
These properties also make it a more attractive precursor for meth synthesis, leading to tighter controls. |
Pseudoephedrine’s β‑dominant activity makes it safer as a decongestant and less likely to cause severe hypertension. This is why it is still available OTC (though regulated) and is the preferred active ingredient in many over‑the‑counter cold remedies. |