Propylhexedrine - PsychonautWiki


Summary sheet: Propylhexedrine
Chemical Nomenclature
Common names Propylhexedrine, Benzedrex
Substitutive name Benzedrex, Obesin
Systematic name 1-cyclohexyl-N-methylpropan-2-amine
Class Membership
Psychoactive class Stimulant
Chemical class Cycloalkylamine
Routes of Administration

WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.

Threshold 10 mg
Light 31.25 - 62.5 mg
Common 62.5 - 125 mg
Strong 125 - 187.5 mg
Heavy 187.5 mg +
Total 4 - 10 hours
Onset 10 - 30 minutes
Come up 15 - 90 minutes
Peak 2 - 5 hours
Offset 1 - 3 hours
After effects 2 - 12 hours

DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.


Propylhexedrine (also known as Benzedrex and Obesin) is a stimulant substance of the cycloalkylamine class. It is a structural analog of methamphetamine. Propylhexedrine is widely used medicinally as a nasal decongestant (for relief of congestion due to colds, allergies and allergic rhinitis) and sometimes used recreationally as an over-the-counter "legal high".

Benzedrex was first manufactured by Smith, Kline and French after the Benzedrine inhaler, which contained racemic amphetamine, became unavailable following the placement of amphetamines on the US Schedule II status (i.e. highest abuse potential, yet with accepted medicinal uses). Propylhexedrine has also been used in Europe as an appetite suppressant under the trade name Obesin. In the United States, propylhexedrine is most commonly found in over-the-counter Benzedrex nasal inhalers.

Subjective effects include stimulation, focus enhancement, motivation enhancement, increased libido, appetite suppression, and euphoria. Anecdotal reports describe propylhexedrine's effects as similar to amphetamine or low-dose methamphetamine. However, it is reported to produce more peripheral effects like vasoconstriction as well as less euphoria, overall resulting in a less "clean" high. In the United States, propylhexedrine is sometimes extracted from over-the-counter Benzedrex nasal inhalers using lemon juice. The health risks of this practice have not been studied.

Due to its amphetamine-like euphoric effects, propylhexedrine is considered to have moderate abuse potential. Chronic use may result in tolerance, physical and psychological dependence. It is highly advised to use harm reduction practices if using this substance.


Propylhexedrine is chemically classified as a cycloalkylamine. It is structurally similar to phenethylamine and its derivates. It is particularly similar in structure to methamphetamine, with the only structural difference being the substitution of an cyclohexane ring for methamphetamine's phenyl ring. This makes propylhexedrine a structural analog of methamphetamine.

Moreover, propylhexedrine is a chiral compound (the α-carbon is chiral), and the product contained in pharmaceutical products is racemic (RS)-propylhexedrine free base. (S)-Propylhexedrine, also known as levopropylhexedrine, is believed to be the more biologically active isomer of the two, although amphetamines with a "levo" suffix are less active than their counterparts. (S)-Propylhexedrine can be synthesized from methamphetamine.[citation needed]

Freebase propylhexedrine is nonpolar, volatile, oily liquid at room temperature, but it readily forms a polar salt when protonated with hydrochloric acid, citric acid, and acetic acid to form a crystalline white substance.[citation needed] As a volatile liquid, it evaporates over time, losing potency drastically quicker than crystalline substances; However, the salt forms are crystalline, and do not evaporate.



This pharmacology section is incomplete.

You can help by adding to it.

Propylhexedrine affects the central nervous system (CNS) by acting as a releasing agent for the monoamine neurotransmitters dopamine, norepinephrine, and serotonin (SNDRA), binding to and reversing their transporters, pumping these neurotransmitters from the cytosol to the synaptic cleft, where these neurotransmitters can bind to their respective receptors. Additionally, propylhexedrine inhibits VMAT2, leading to a further increase in the aforementioned monoamines, being that VMAT2 transports all 3 from the synaptic cleft to the cytosol.[citation needed]

Propylhexedrine, like phenethylamine, amphetamine, methamphetamine, and MDMA, agonizes TAAR1. TAAR1 agonism, through protein kinase A & C (PKA and PKC) signaling, causes dopamine transporter (DAT) phosphorylation. Both PKA and PKC result in non-competitive dopamine reuptake inhibition, although PKC alone results in dopamine release/DAT reversal.

The pharmacological actions of propylhexedrine are similar to those of phenethylamines, such as amphetamines, albeit in a generally less centrally active and recreationally desirable fashion.[1]

Since propylhexedrine has a cyclohexane ring in the place of methamphetamine's phenyl ring, it lacks the level of Brain-Blood Barrier permeability that the phenyl ring provides amphetamines, and therefore has a greater proportion of effects on the peripheral nervous system relative to the central nervous system.[2]

Propylhexedrine has a half-life of 2.5 - 6.5 hours, which is variable based on urinary pH and the level of activity of certain Cytochrome P450 enzymes. Higher urinary pH elongates duration, while low urinary pH shortens duration. Higher activity of certain Cytochrome P450 enzymes also shortens duration.[3]

Propylhexedrine is metabolized by certain Cytochrome P450 enzymes into norpropylhexedrine, cyclohexylacetoxime, cis-4-hydroxypropylhexedrine and trans-4-hydroxypropylhexedrine.[3]

Subjective effects

This subjective effects section is a stub.

As such, it is still in progress and may contain incomplete or wrong information.

You can help by expanding or correcting it.

Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), a research literature based on anecdotal reports and the personal experiences of PsychonautWiki contributors. As a result, they should be regarded with a healthy degree of skepticism. It is worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become much more likely with higher doses and may include addiction, serious injury, or death.

Physical effects

Visual effects

Cognitive effects

After effects

Experience reports

Anecdotal reports which describe the effects of this compound within our experience index include:

Additional experience reports can be found here:

Toxicity and harm potential

The toxicity of recreational propylhexedrine use has not been studied as extensively as that of amphetamine or methamphetamine but it is reasonable to assume that most if not all of the same risks apply.

It is strongly recommended that one use harm reduction practices when using this substance.

Tolerance and addiction potential

As with other stimulants, the chronic use of propylhexedrine can be considered highly addictive, and is capable of causing psychological and physiological dependence among certain users. When addiction has developed, cravings and withdrawal effects may occur if a person suddenly stops or drastically decreases their usage.

Tolerance to the effects of this compound likely occurs in the same general fashion as with amphetamine rapidly develops with prolonged and repeated use.[4][5] This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). Propylhexedrine presents cross-tolerance with all dopaminergic stimulants, meaning that after the consumption of propylhexedrine all stimulants will have a reduced effect.

Like with amphetamine and methamphetamine the evidence on effective treatments for dependence and abuse is limited.[6] In light of this, fluoxetine and imipramine appear to have some limited benefits in treating abuse and addiction[6]

In highly dependent amphetamine and methamphetamine abusers, "when chronic heavy users abruptly discontinue methamphetamine use, many report a time-limited withdrawal syndrome that occurs within 24 hours of their last dose".[7] Withdrawal symptoms in chronic, high-dose users are frequent, occurring in up to 87.6% of cases, and persist for three to four weeks with a marked "crash" phase occurring during the first week.[7] Methamphetamine withdrawal symptoms can include anxiety, drug craving, dysphoric mood, fatigue, increased appetite, increased movement or decreased movement, lack of motivation, sleeplessness or sleepiness, and vivid or lucid dreams.[7] Withdrawal symptoms are associated with the degree of dependence (i.e., the extent of abuse).[7] The mental depression associated with methamphetamine withdrawal lasts longer and is more severe than that of cocaine withdrawal.[1]. It is likely that propylhexedrine abuse is subject to these same outcomes.


Main article: Stimulant psychosis

Like with the abuse of methamphetamine, propylhexedrine abuse can result in a stimulant-induced psychotic state that may present with a variety of symptoms (e.g., paranoia, hallucinations, delusions), though likely to a lesser degree.[8][9] A review on treatment for amphetamine, dextroamphetamine, and methamphetamine abuse-induced psychosis states that about 5–15% of users fail to recover completely.[9][10] The same review asserts that, based upon at least one trial, antipsychotic medications effectively resolve the symptoms of acute amphetamine psychosis.[9]

Dangerous interactions

Although many psychoactive substances are reasonably safe to use on their own, they can suddenly become dangerous or even life-threatening when combined with other substances. The following list includes some known dangerous combinations (although it is not guaranteed to include all of them). Independent research (e.g. Google, DuckDuckGo) should always be conducted to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.

  • Tricyclic antidepressants - Propylhexedrine may increase the effects of tricyclic antidepressants to dangerous levels.[11]
  • 25x-NBOMe & 25x-NBOH - Members of the 25x family are highly stimulating and physically straining. Combinations with stimulants should be avoided due to the risk of excessive stimulation. This can result in panic attacks, thought loops, seizures, increased blood pressure, vasoconstriction, and heart failure in extreme cases.
  • Alcohol - Alcohol can be dangerous to combine with stimulants due to the risk of accidental over-intoxication. Stimulants mask the sedative effects of alcohol, which is the main factor people use to assess their degree of intoxication. Once the stimulant wears off, the depressant effects of alcohol are left unopposed, which can result in blackouts and respiratory depression. If combined, one should strictly limit themselves to only drinking a certain amount of alcohol per hour.
  • DXM - Combinations with DXM should be handled with extreme care due to DXM's effects on serotonin and norepinephrine reuptake. This can lead to panic attacks, hypertensive crisis, or serotonin syndrome with stimulants that increase levels of serotonin (MDMA, methylone, mephedrone, etc.). Monitor blood pressure carefully and avoid strenuous physical activity.
  • MDMA - The neurotoxic effects of MDMA may be increased when combined with other stimulants. There is also a risk of excessive heart strain.
  • MXE - Combinations with MXE may dangerously elevate blood pressure and increase the risk of psychosis.
  • Stimulants - Propylhexedrine can be potentially dangerous in combination with other stimulants like cocaine as they can increase one's heart rate and blood pressure to dangerous levels.
  • Tramadol - Tramadol lowers the seizure threshold.[12] Combinations with stimulants may further increase this risk.

Legal status


This legality section is a stub.

As such, it may contain incomplete or wrong information. You can help by expanding it.

  • Canada: Propylhexedrine is not controlled under the schedules to the Controlled Drugs And Substances Act.[citation needed]
  • Germany: Propylhexedrine is a prescription only medicine, according to Anlage 1 AMVV (Medicine Prescribing Regulation, Schedule 1).[14]
  • Switzerland: Propylhexedrine is not controlled under Buchstabe A, B, C and D. It is sporadically used medicinally.[15]
  • United States: Propylhexedrine is a legal OTC drug. It is designed not to be recreationally used unless the user decides to bypass the manufacturer's intended design with which it was granted approval to market as a nasal decongestant. The simple consumption of this substance is not technically considered illegal.[citation needed]

See also

External links


  1. 1.0 1.1 Methamphetamine abuse ( / NCBI) |
  2. 12
  3. 3.0 3.1 K. K. Midha, A. H. Beckett & A. Saunders (1974) Identification of the Major Metabolites of Propylhexedrine in vivo (in man) and in vitro (in guinea pig and rabbit), Xenobiotica, 4:10, 627-635, DOI: 10.1080/00498257409169765
  4. Efficacy of psychostimulant drugs for amphetamine abuse or dependence ( / NCBI) |
  5. Amphetamines, By Patrick G. O’Connor, MD, MPH, Yale University School of Medicine |
  6. 6.0 6.1 Treatment for amphetamine dependence and abuse ( / NCBI) |
  7. 7.0 7.1 7.2 7.3 Treatment for amphetamine withdrawal ( / NCBI) |
  9. 9.0 9.1 9.2 Shoptaw, S. J., Kao, U., & Ling, W. (2009). Treatment for amphetamine psychosis. The Cochrane Library.
  10. Hofmann FG (1983). A Handbook on Drug and Alcohol Abuse: The Biomedical Aspects (2nd ed.). New York: Oxford University Press. p. 329. ISBN 9780195030570.
  11. Adderall Prescription info |
  12. Talaie, H.; Panahandeh, R.; Fayaznouri, M. R.; Asadi, Z.; Abdollahi, M. (2009). "Dose-independent occurrence of seizure with tramadol". Journal of Medical Toxicology. 5 (2): 63–67. doi:10.1007/BF03161089. eISSN 1937-6995. ISSN 1556-9039. OCLC 163567183. 
  13. Gillman, P. K. (2005). "Monoamine oxidase inhibitors, opioid analgesics and serotonin toxicity". British Journal of Anaesthesia. 95 (4): 434–441. doi:10.1093/bja/aei210 . eISSN 1471-6771. ISSN 0007-0912. OCLC 01537271. PMID 16051647. 
  14. "Anlage 1 AMVV" (in German). Bundesministerium der Justiz und für Verbraucherschutz. Retrieved December 28, 2019. 
  15. "Verordnung des EDI über die Verzeichnisse der Betäubungsmittel, psychotropen Stoffe, Vorläuferstoffe und Hilfschemikalien" (in German). Bundeskanzlei [Federal Chancellery of Switzerland]. Retrieved January 1, 2020.