From PsychonautWiki
Jump to navigation Jump to search

This page has not been approved by the PsychonautWiki administrators.

It may contain incorrect information, particularly with respect to dosage, duration, subjective effects, toxicity and other risks.

Skull and crossbones darktextred2.png

Death may occur when promethazine is combined with other depressants, such as opioids, benzodiazepines, barbiturates, thienodiazepines or other GABAergic substances like alcohol.[1]

Additionally, promethazine is an anticholinergic, and at high doses it may cause delirium and extremely unpleasant if not dangerous experiences. Please be extremely careful when trying this pharmaceutical and use responsible use practices such as always having a tripsitter when using promethazine, especially at high doses.

Summary sheet: Chlorpheniramine
Chemical Nomenclature
Common names Chlorphenamine, Chlor-Trimeon
Class Membership
Psychoactive class Depressant / Deliriant
Chemical class Alkylamine
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 1 - 2 mg
Light 2 - 4 mg
Common 4 - 6 mg
Strong 6 - 10 mg
Heavy 10 mg +
Total 4 - 6 hours
Onset 30 - 60 minutes
Come up 20 - 40 minutes
Peak 1 - 3 hours
Offset 4 - 6 hours
After effects 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.

Chlorpheniramine (commonly sold as Chlor-Trimeton is a first-generation antihistamine of the alkylamine chemical class that produces muscle relaxing, nausea relieving and sedative effects when administered. It also reduces motion sickness and has anticholinergic properties.

Chlorphenamine was patented in 1948 and came into medical use in 1949.[3] It is available as a generic medication and over the counter.

Today, Chlorphenamine is available in many countries under many brand names, it has been shown to have some hypnotic effects and is sometimes used off-label for this purpose.

History and culture

History icon.svg

This History and culture section is a stub.

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

Brand names have included Demazin, Allerest 12 Hour, Codral Nighttime, Chlornade, Contac 12 Hour, Exchange Select Allergy Multi-Symptom, A. R. M. Allergy Relief, Ordrine, Ornade Spansules, Piriton, Teldrin, Triaminic, and Tylenol Cold/Allergy.



This chemistry section is incomplete.

You can help by adding to it.

Chlorphenamine is a alkylamine-based compound.


Pill bottle-o.png

This pharmacology section is incomplete.

You can help by adding to it.

Chlorphenamine acts primarily as a potent H1 antihistamine. It is specifically a potent inverse agonist of the histamine H1 receptor. The drug is also commonly described as possessing weak anticholinergic activity by acting as an antagonist of the muscarinic acetylcholine receptors. The dextrorotatory stereoisomer, dexchlorpheniramine, has been reported to possess Kd values of 15 nM for the H1 receptor and 1,300 nM for the muscarinic acetylcholine receptors in human brain tissue.[19][20] The smaller the Kd value, the greater the binding affinity of the ligand for its target.

In addition to acting as an inverse agonist at the H1 receptor, chlorphenamine has been found to act as a serotonin reuptake inhibitor (Kd = 15.2 nM for the serotonin transporter).[8][21] It has only weak affinity for the norepinephrine and dopamine transporters (Kd = 1,440 nM and 1,060 nM, respectively).A similar antihistamine, brompheniramine, led to the discovery of the selective serotonin reuptake inhibitor (SSRI) zimelidine.[citation needed]

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

Cognitive effects

Visual effects

After effects
Aftereffects (3).svg

Experience reports

There are currently no anecdotal reports which describe the effects of this compound within our experience index. Additional experience reports can be found here:

Toxicity and harm potential


This toxicity and harm potential section is a stub.

As a result, it may contain incomplete or even dangerously wrong information. You can help by expanding upon or correcting it.
Note: Always conduct independent research and use harm reduction practices if using this substance.

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

Lethal dosage

The lowest published toxic dose of promethazine in humans (oral) is 3.5 mg/kg. This means that a person weighing 70 kg can show signs of toxicity at 245 mg. The LD50 of promethazine in mice (oral) is 255 mg/kg. If applied to humans, this suggests that 50% of people weighing 70 kg would die after consuming 17.85 grams of promethazine. [3]

Tolerance and addiction potential

Promethazine is not addictive.

Dangerous interactions


This dangerous interactions section is a stub.

As such, it may contain incomplete or invalid information. You can help by expanding upon or correcting it.

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. Promethazine, because of its extensive pharmacology, has many interactions. According to the interactions checker on, promethazine is known to interact with over 1000 other prescription and OTC drugs.

  • Depressants (1,4-Butanediol, 2-methyl-2-butanol, alcohol, barbiturates, GHB/GBL, methaqualone, opioids) - This combination can result in dangerous or even fatal levels of respiratory depression. These substances potentiate the muscle relaxation, sedation and amnesia caused by one another and can lead to unexpected loss of consciousness at high doses. There is also an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should try to fall asleep in the recovery position or have a friend move them into it.
  • Anti-dopaminergics - Because promethazine also blocks dopamine receptors, other drugs and substances that do this will increase the chances of developing acute or tardive dyskinesia, neuroleptic malignant syndrome, or parkinsonism. [citation needed]
  • Anticholinergics - Promethazine with anticholinergics (or antimuscarinics) can cause increased blocking of acetylcholine, being potentially dangerous with cardiovascular effects as well as delirium. [citation needed]
  • Stimulants - Due to promethazine's excitatory cardiac effect, combining it with stimulants poses a risk of an abnormal heart rhythm, severe tachycardia, or a heart attack as well as other cardiovascular events.

Legal status


This legality section is a stub.

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

See also

External links



  1. Risks of Combining Depressants (Tripsit) |
  2. Tsay, M. E., Procopio, G., Anderson, B. D., & Klein-Schwartz, W. (2015). Abuse and intentional misuse of promethazine reported to US poison centers: 2002 to 2012. Journal of addiction medicine, 9(3), 233-237. | PubMed Link: