|Summary sheet: Efavirenz|
|Common names||Efavirenz, Sustiva|
|Routes of Administration|
Efavirenz (sold by the brand name Sustiva) is an antiretroviral medication used in the treatment and prevention of HIV/AIDS. It is notable for being able to produce psychedelic and hallucinogenic effects despite possessing an extremely novel pharmacological profile and chemical structure not shared with any other psychedelic substance.
Efavirenz was approved for medical use in the United States in 1998. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.
Recreational use of efavirenz for its hallucinogenic and dissociative effects has been reported in South Africa. The tablets are reportedly crushed and smoked in a mixture known as "whoonga" , "nyaope" , and "wonga". A form of black tar heroin. Although current analyses of whoonga samples have yet to confirm the presence efavirenz in the mixture. 
Unlike most psychedelics, efavirenz is not a tryptamine, phenethylamine or lysergamide. Efavirenz is classified as a benzoxazine and has several different moieties which give it a unique pharmacological profile. On the two position of the benzoxazine ring, efavirenz has a ketone attached. Efavirenz also has a trifluoromethyl group as well as a cyclopropane ring.
Efavirenz is a white to slightly pink crystalline powder with a molecular mass of 315.68 g/mol. It is practically insoluble in water (<10 µg/mL).. Efavirenz is chemically described as (S)-6-chloro-(cyclopropylethynyl)-1,4-dihydro-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one. Its empirical formula is C14H9ClF3NO2.
Pharmacologically, efavirenz is primarily classified as a non-nucleotide reverse transcriptase inhibitor, or NNRTI. Reverse transcriptase is an enzyme found in several viral species that is a type of DNA polymerase and nuclease that allows viruses like hepatitis and human immunodeficiency virus to transcribe viral RNA into DNA. Efavirenz is considered a non-nucleotide reverse transcriptase inhibitor because it does not have a structure based off of a nucleotide.
Unlike most non-nucleotide reverse transcriptase inhibitors, efavirenz is also a 5-HT2A partial agonist, similar to LSD. Additionally, efavirenz is a serotonin and dopamine reuptake inhibitor and a vesicular monoamine transporter 2 inhibitor. Efavirenz also acts as a GABAA positive allosteric modulator, similar to benzodiazepines and barbiturates. Efavirenz has a bioavailability of about 40-45% when it is taken on an empty stomach.
Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWiki contributors. As a result, they should be viewed with a healthy degree of skepticism.
It is also 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 increasingly likely with higher doses and may include addiction, severe injury, or death ☠.
- Drifting (melting, breathing, morphing and flowing)
- After images
- Colour replacement
- Colour shifting
- Scenery slicing
- Symmetrical texture repetition
- Tracers - This is considered the most common visual effect of efavirenz.
The geometry found within efavirenz is generally extremely mild, and for many users, it may not happen at all.
Toxicity and harm potential
Efavirenz has a low toxicity relative to dose. Like many HIV medications, efavirenz may cause liver toxicity at high doses or after chronic use.
It is strongly recommended that one use harm reduction practices when using this drug.
Tolerance and addiction potential
Efavirenz is not known to be habit-forming. While developing a tolerance to efavirenz is extremely rare, abusing efavirenz may cause HIV to become resistant to the drug and increase the viral load in patients with HIV.
As efavirenz may cause hepatoxicity at high doses or after chronic use, it is not recommended to take this substance concurrently with other substances that may cause hepatoxicity. Efavirenz is an inducer of the CYP2B6 and CYP3A4 enzymes of the cytochrome P450 system, and as a result may change the metabolism of drugs metabolized by them. Consuming garlic may decrease serum levels of efavirenz.
Serotonin syndrome risk
Efavirenz is a weak serotonin reuptake inhibitor, so it is possible that combining heavy doses of efavirenz and the substances listed below may result in serotonin syndrome. Combinations with the following substances can cause dangerously high serotonin levels. Serotonin syndrome requires immediate medical attention and can be fatal if left untreated.
This legality section is a stub.
As such, it may contain incomplete or wrong information. You can help by expanding it.
Efavirenz is not known to be illegal in any jurisdictions, and is considered a prescription only medication.
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- New item… Vrouenraets, S. M., Wit, F. W., Tongeren, J. van, Lange, J. M. (April 2007). "Efavirenz: a review". Expert Opinion on Pharmacotherapy. 8 (6): 851–871. doi:10.1517/146565220.127.116.111. ISSN 1465-6566.
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- Getting high on HIV drugs in S Africa, 2008
- News, A. B. C., “No Turning Back”: Teens Abuse HIV Drugs
- Vice (2014), Getting High On HIV Medication - Part 1/2
- Gatch, M. B., Kozlenkov, A., Huang, R.-Q., Yang, W., Nguyen, J. D., González-Maeso, J., Rice, K. C., France, C. P., Dillon, G. H., Forster, M. J., Schetz, J. A. (November 2013). "The HIV Antiretroviral Drug Efavirenz has LSD-Like Properties". Neuropsychopharmacology. 38 (12): 2373–2384. doi:10.1038/npp.2013.135. ISSN 1740-634X.
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- "Anlage 1 AMVV" (in German). Bundesministerium der Justiz und für Verbraucherschutz. Retrieved December 11, 2019.