Tuesday, 16th October 2018

Research Articles


Legal Highs, Ethnobotanicals & Research Chemicals - Incidence and usage of less-common (write-in) psychoactive substances reported by IDMU Survey respondents 1997-2011

Tables of data deleted to save space - for full articles with data tables - click here to download.


Introduction & Methodology


The annual IDMU drug-user surveys list the most commonly-found drugs in order to monitor consumption patterns, attitudes and prices.  In addition respondents are asked to name any other drugs or psychoactive substances they have taken as ‘write-in; options using anonymous paper or web-based questionnaires. This report highlights the substances most frequently listed by survey respondents, or substances which may be of particular interest to researchers.  Substances include ‘traditional’ drugs, ethnobotanicals, legal highs and ‘research chemicals’.


Recording methods have varied with limited data available for many of the years, with drug name/ratings being the only ever-present variables.  Where data is available it includes prices at different market levels (1-100 doses, gram/ounce), user ratings (marks out of 10), age at first use, frequency of use, weekly use, monthly spending, and methods of use.


A shift is the survey design from entirely paper based to entirely web-based has occurred gradually between 2004 and 2011, the web forms allow more specific questions to be asked, and also tend to attract a higher proportion of users than in samples recruited at pop-festival stalls.  As a result the proportions of respondents reporting ‘write-in’ drugs has nearly quadrupled from 7% between 1997 and 2006 to 27% between 2007 and 2011 (table 1)


Table 1 – Survey Sizes and Incidence of Write-In Drug Reports































* Jan-June 2011 Interim Data


The data excludes results for named drugs, which include:


Cannabis (all types)

Amphetamines – street. ‘base’ and methamphetamine

Cocaine & Crack

Heroin, Opium, Opiate painkillers, Methadone

LSD, Magic Mushrooms, Ecstasy Tablets & MDMA powder

Ketamine, GHB, Mephedrone, Tranquillisers, Solvents

Caffeine, Alcohol, Tobacco


Where a drug has proven particularly common it may be added to the list of named drugs for the following year’s survey.

Incidence of ‘Write-In’ Drug Usage


The most commonly reported write-in drugs (Table 2) were Salvia Divinorum, 2-CB & variants, DMT and variants, Mescaline (inc Peyote) and cathinones (exc methadone but including Khat).  Percentages refer to the percentage of total write-ins (% W) with the overall prevalence among the total respondents (% T).  Surveys have been divided into three 5-year cohorts in order to assess trends, listed in descending order of prevalence.


Tables of data deleted to save space - for full articles with data tables - click here to download.


Usage of and attitudes to write-in drugs


Table 3 summarises the available data on frequency of usage for the write-in drugs.


Table 4 summarises the available data on attitudes of users to drugs and usage variables including age of first use, weekly use (grams/tabs/doses) and monthly spending where given (excluding zero values).  Drugs are listed in descending order of user-rating (most-least favoured).


Table 5 lists the available data on how the write-in drugs are taken, with options including nasal (snorting), smoking, eating (inc drinking) and injection.


Prices of Write-in Drugs


Table 6 lists the prices, where available, for individual doses, 10 doses, 100 doses, 1 gram and 1 ounce of the drugs listed.


Tables of data deleted to save space - for full articles with data tables - click here to download.




The results for the following substances reported by survey respondents, and brief descriptions thereof, are summarised below in descending order of overall prevalence.


Salvia Divinorum – 636 reports - appears as a leafy plant substance either natural (approx 0.2%) or fortified with concentrated extracts, the main active substance is Salvinorin A, a terpenoid and mild short-acting hallucinogen.  It is almost invariably smoked, often as an alternative to cannabis.  It is by far the most commonly-reported write-in drug, with usage growing, from 7% of write-in reports in the late 1990s to 30% of reports in the early 2000s.  The vast majority of users have only taken the drug on a few occasions with only 6% of respondents to frequency questions stating regular or daily use.  It has a neutral to mildly positive average user-rating.  Salvia remains legal in the UK at the time of writing.


2-CB and variants (2-CE, 2-CI, 2-CT7) – 304 reports - are phenethylamine analogues with similar effects to ecstasy, normally appearing as tablets but also as a powder which can be snorted or used orally.  Usage has remained stable at between 9% and 12% of write-in reports over the past 15 years.  It has a positive user-rating.  Approx 5% of users are regular.  Class A.


DMT (nn-dimethyltryptamine)  - 241 reports - is a short-acting hallucinogen normally appearing as a powder which is typically smoked.  Incidence appears to be declining from 15% of write-in reports between 1997-01 to 6% from 2007-11. Approx 5% of users are regular.  Very strong positive user-rating. Class A.


Mescaline/Peyote - 146 reports - is a traditional hallucinogen either synthetic or naturally occurring in the Peyote or San Pedro cactus.  Oral ingestion is most common although the powdered cactus can be smoked or the synthetic drug snorted on occasion.  Usage was relatively common (8.5% of write-ins) between 1997-2006 but has fallen away (1.3%) in the past 5 years.  4% of users reported doing so on a regular basis.  Legal in natural form (Peyote) otherwise Class A if synthesised or in preparations.


Cathinones & Khat – 107 reports of which 39 for Khat only - Cathinones are stimulant drugs with similar effects to amphetamine or cocaine, the best known cathinone would be Mephedrone (4-methylmethcathinone), first reported in the 2008 survey and which soared in popularity in 2010 to be included as a named drug in the survey.  Virtually all the write-in reports prior to 2006 were for the natural form of Khat (Catha Edulis), traditionally used amongst Yemeni and Somali communities in the UK.  Incidence of khat use has declined (only 6x reports in past 5 years).    The class includes substituted cathinones (methcathinone, methylone, methadrone) and pyrovalerones (MDPV, Naphyrone) and street names for these substances.  Only 4% of Khat users report regular use, rising to 25% of synthetic cathinone users.  Natural khat has a neutral user-rating with synthetic cathinones a mild to high positive rating.   Natural khat is normally chewed or otherwise taken orally, occasionally smoked, synthetics are most commonly taken orally or snorted. Cathinones (or preparations containing cathinones) became class B drugs in 2010, natural Khat remains legal in the UK.


Smoking Mixtures –  99 reports - These come under a wide variety of brand names, marketed as ‘legal’ cannabis substitutes (not including ‘Spice’ and variants), incidence has trebled from 1.4% of write-ins in early surveys to 4.6% from the most recent cohort.  These generally receive poor user-ratings.  The content is not usually disclosed and thus legal position is likely to vary.


Miscellaneous Pills – 98 reports - These can encompass unknown pills and capsules which contain illegal drugs (e.g. Ecstasy or BZP) or legal or inert substances, to brand-named pills offering allegedly legal alternatives to ecstasy, LSD, amphetamine or cocaine.  Incidence has trebled each 5 year period from 0.5% of write-ins in the earliest cohort to 5.5% in the latest.  Regular or daily use approx 6% of users, neutral overall rating (wide variation), legality varies according to content.


BZPBenzylpiperazine – 90 reports - (BZP) is the most common of the substituted piperazines - designer drugs with a similar action to ecstasy, although chemically unrelated.  BZP was originally used medicinally as an anti-worm treatment and was proposed as an antidepressant before the stimulant properties caused concern.  Seizures of BZP have been recorded by FSS since 2005, and grew significantly in 2007-8 to exceed the number of Ecstasy seizures early in 2009.  BZP first appeared as a single report in the 2006 survey.   Mild negative-neutral user-rating with 11% of users reporting regular use (none daily).    In December 2009 BZP and other substituted piperazines were designated as Class C controlled drugs in the UK.

LSA – 84 reports = Lysergic Acid Amide is related to LSD and most commonly found in natural products (Morning Glory seeds, Hawaiian Baby Woodrose seeds).  Incidence appears to have declined over the past 5 years.  Approx 6% of users report regular use, mildly positive user-rating.  Class A when not in natural product.


N2O – 66 reports - Nitrous Oxide (Laughing gas) is most commonly used as a short-acting anaesthetic in dental surgery and obstetrics.  Incidence is relatively stable or declining slightly.  It is found in compressed cylinders and also as a propellant in canisters of ‘squirty cream’ and produces mild intoxication to unconsciousness depending on the dose.  Regular use among 15% of users, no reports of daily use, positive user rating.  Legal in the UK.


Spice – 60 reports - is/was a brand-named product sold as a ‘legal high’ (cannabis substitute) before being scheduled as a class B drug in 2009 with the active constituent being a synthetic cannabinoid JWH-018, it has only appeared in the past 5 years.  Around 25% of users report regular use, but it has only a neutral user-rating.


Miscellaneous Powders – 51 reports - include unknown powders and various brand-named products sold as legal alternatives to ecstasy, amphetamine or cocaine.  Most likely to contain cathinones or pyrovalerones now banned as Class B drugs since 2010.  4% regular use, neutral user-ratings.


Cactus – 42 reports - data includes un-named and San Pedro (excludes Peyote).  Contents of San Pedro cactus include Mescaline and a range of phenethylamines (similar to Ecstasy).  Incidence declined after peak in early 2000s, no reports of regular use, positive user-rating. Legal in natural form otherwise Class A if in preparations.


Datura stramonium – 33 reports - (Thorn-apple, Jimson Weed) – Contains Atropine – a muscle relaxant and dissociative/deliriant, also found in deadly nightshade and other natural products, as well as scopolamine and hyoscyamine which are hallucinogenic .  Highly toxic with risk of fatal overdose.   Usage declined significantly with only 2 reports in past 5 years.  Only one respondent has reported regular use, neutral to slight-positive user-rating,   Legal in UK but Atropine subject to poisons legislation.


Fly Agaric Mushrooms – Amanita Muscaria – 33 reports - The traditional ‘fairy tale’ toadstool with red cap and white spots, contains ibotenic acid and muscimol, ibotenic acid is known to be highly neurotoxic and converts to muscimol in the body.  Muscimol is a deliriant and hallucinogen with entheogenic properties and the mushrooms have a long history of shamanic use in Northern Europe.  Usage in the UK has declined significantly, no reports of regular use and a neutral user-rating.  Legal in the UK.


Kratom –33 reports -  this is derived from a tree Mitragyna speciosa from SE Asia, and appears as dried leaf or in capsule form.  Active substances include  alkaloids 7-hydroxymitragynine and mitragynine which although structurally similar to tryptamines are not psychedelic but instead are believed to act on opiate receptors, making the drug useful in opiate withdrawal.  First reported in 2004 survey.  2x of respondents reported regular use,   Currently legal in UK but banned in some countries.


Ayahusaca - 30 reports – This is a traditional south American brew mixing powdered vine Banisteriopsis caapi - containing MAO-inhibitors (Harmine, Harmaline) with other plants e.g Psychotria viridis or Diplopterys cabrerana - containing dimethyltryptamine (DMT) used in shamanic rituals.  The effect is profoundly psychedelic and long-lasting due to the MAOI content.  Usage declined over past 5 years but very highly positive user-ratings.  2x reports of regular use.  Recent prison sentence for organiser of ritual workshop in UK – The brew is Class A, although natural plant sources legal in natural form if ‘unprepared’.


DXM – Dextromorphan – 29 reports – DXM is found in cough mixtures (e.g. Robitussin) as a cough-suppressant, but in high dosages acts as a dissociative hallucinogen similar to ketamine or PCP.  Usage slightly declined in past 5 years, but one in four users take regularly, mild-mid positive user-rating.  Legal in the UK.


SSRI antidepressants – 28 reports – Selective serotonin reuptake inhibitors include fluoxetine (prozac), paroxetine (seroxat) and others.  Prescribed as anti-depressants but some non-prescribed use, e.g. to intensify or prolong the effects of ecstasy type drugs.  Usage declined significantly in past 5 years but 52% of users used daily (inc prescription users), mid-positive user-rating.  Prescription only medicine but otherwise legal in UK.

Ephedrine – 25 reports - is a stimulant falling mid-way in potency between caffeine and the amphetamines, commonly found in cold remedies and decongestants but also in natural products (Ma Huang), or sold as ‘legal speed’.  Usage declining, but 25% of users take regularly.  Mild positive user-rating.  Legal in the UK but banned in some countries.


Kava Kava – 25 reports – This is a drink prepared from the root of a Polynesian plant of the same name, with active ingredients believed to be kavalketones, producing relaxation and mild euphoria.  No reports in past 5 years.  2x reports of regular use, mild positive user-ratings.  Legal in the UK but sale for human consumption prohibited due to concerns over risk of liver damage.


Nutmeg - Myristica fragrans – 25 reports – Nutmeg is familiar to most people as the popular spice used widely in cooking and baking, the active ingredient is myristicin which in high doses is psychoactive, deliriant and potentially toxic.  Recreational use is declining, no respondents progressed beyond experimental use, negative user-ratings.  Legal in the UK.


Guarana – 18 reports – mild herbal stimulant (caffeine) used e.g. in energy drinks and also sold in powder form.  Usage probably much more widespread than reported by respondents.  No reports in past 5 years but one in 6 use regularly.  Mid-positive user-rating.  Legal in the UK


AMT – alpha-methyltryptamine – 12 reports - an analogue of DMT and other psychedelic tryptamines, includes methoxy-variants.  Majority of reports were from past 5 years.  No reports of regular use, strong positive user-rating.  Not controlled and marketed as a legal high.


PCP (Phencyclidine) aka ‘Angel Dust’ – 12 reports – Dissociative anaesthetic similar to Ketamine, popular in USA ion the 1970s/1980s but rarely found in the UK and most reports likely to have arisen from US respondents to the surveys.  No discernable trends in usage – a handful of reports for each cohort.  No reports of regular use, slight negative user-rating.  Class A


Wormwood (Artemisia absinthium) – 12 reports – contains thujones which have medicinal properties and also psychoactive as mild hallucinogen and toxic in high doses.  Most commonly found in the alcholic drink Absinthe or as dried leaves and flowers (brewed or smoked).  3x respondents report regular use, mid-positive user rating, legal in the UK.


Ritalin (Methylphenidate) – 11 reports – Used therapeutically to treat behavioural disorders in children, mild stimulant effect.  Only 2 reports in past 5 years, mid-positive user rating, one in three take regularly or daily (inc prescribed).  Prescription-only medicine.


Benzo Fury (6-APB) – 11 reports –  6-(2-aminopropyl)benzofuran - synthetic stimulant/entactogen structurally related to amphetamines and phenethylamines.  1 respondent reports regular/daily use, all reports from past 2 years, strong positive user-rating.  Legal in the UK but branded products may not be as advertised.


MDA/MDAI – 10 reports -  MDAI (5,6-Methylenedioxy-2-aminoindane) is a serotonic releasing agent which has entactogenic effects similar to ecstasy, allegedly legal in UK due to closed-ring structure around nitrogen atom.  MDA (3,4-Methylenedioxyamphetamine) is closely-related to ecstasy and a Class A drug.  70% of reports from past 5 years, no reports of regular use, mild negative user-rating.


STP/DOM - 2,5-Dimethoxy-4-methylamphetamine – 9 reports - hallucinogenic substituted amphetamine first appearing in the late 1960s (STP standing for ‘serenity, tranquillity and peace”), originally as legal alternative to LSD.  Usage stable but rare, no discernable trends, strong positive user-rating, no reports of regular use, Class A.


Coca Leaf – 8x reports – leaves of coca plant brewed as tea or chewed with alkaline substance to aid absorbtion of cocaine alkaloids.  Mild stimulant effect due to low dosage/drug content.  No reports in past 5 years, 1x report of regular/daily use, mid-positive user rating.  Legal in UK in natural form but class A if prepared in any way.


JWH-018 - 8 reports - 1-pentyl-3-(1-naphthoyl)indole is a synthetic non-cannabinoid which acts as a cannabinoid-receptor agonist, giving similar effects to those of cannabis.  It was banned in the UK in December 2009 (Class B) as the main active ingredient of ‘Spice’ artificial cannabis smoking mix.  All reports from past 5 years, no reports of regular use, mid-positive user rating.


Syrian Rue (Paganum harmala) – 6 reports – this is a hardy aridophilic plant with alkaloids harmine and harmaline (MAO inhibitors) used as an alternative to Banisteriopsis Caapi in Ayahuasca preparations (combined with DMT or related indole), reputed to have mild entheogenic effects.  No discernable trends, no reports of regular use, mid-positive user rating.  Legal in UK.


Ibogaine – 4 reports – Tabernanthe iboga – contains a strong hallucinongen and dissociative reputed to cure addictions and dependencies.  Originally from west Africa.  A handful of reports with no discernable trends, no users beyond experimental. Highly positive user-ratings.  Class A.


Mandrax (methaqualone) – 4 reports – Popular ‘sleeping pills’ in the 1960s and 1970s until withdrawn from medical practice.  Also known as ‘Mandies’ ‘Quaaludes’ or simply ‘ludes’.  A handful of reports, none in past 5 years.  No reports of regular use, neutral to mild positive user-ratings.  Class B.


Yohimbe – 4 reports - Pausinystalia yohimbe – derived from bark of tree containing tryptamine-derivative Yohimbine (hallucinogenic) – used therapeutically in treatment of sexual dysfunction and also in some weight-loss supplements.  Legal in UK


Toads – 3 reports – Several species of toads produce Bufotenin, a tryptamine hallucinogen related to psilocybin and DMT, with highest concentrations in the venom and skin, which may be licked in certain places to obtain the drug ‘toad-licking’.  Three reports, one from the USA, no regular use, no reports in past 5 years, very strong positive user-ratings.  Bufotenin is a class A drug, as would be any preparation (e.g. dried toad skin), although living toads are legal (even protected species).




The write-in options on the IDMU surveys offer a valuable ‘early warning’ system for new psychoactive drugs appearing on the UK market.  There has been a notable (4-fold) increase in the incidence of write-in drugs over the past 5 years, and although part of this is attributable to improvements in survey methodology and data collection, the increasing availability of so-called ‘legal highs’ from ‘head-shops’ and via the internet is clearly a major factor.


The most common write-in drugs are Salvia Divinorum – used relatively widely but infrequently, followed by 2-CB (enthogen), DMT & Mescaline (hallucinogens) and cathinones (stimulants).  None of the other substances has been reported by more than 0.5% of survey respondents as a whole.


For the vast majority of ‘write-in’ drugs usage is overwhelmingly experimental in nature, however regular use is found amongst significant proportions of users of stimulants (cathinones, ephedrine, guarana, Ritalin) and SSRIs.


The most positive user-ratings were for the psychedelic drugs (tryptamines and Mescaline) in natural or synthetic form, the most negative ratings were for nutmeg and certain so-called ‘legal highs’.