The analysis of post-frequent and drug-related discussions on international Internet forums generated 51 categorized topics based on 13,082 user posts, which were combined into four overarching themes of discussion: (1) uncovering the substance facts, (2) dosage and administration, (3) subjectively experienced effects, and (4) support and safety. The themes are presented below with some representative quotations.

Uncovering the substance facts

This theme incorporates the users’ discussions about specific NPS and their objective properties and appearance. A wide variety of known NPS, such as different types of synthetic cannabinoids, stimulants, dissociatives, and hallucinogens, were discussed. See Table 2 for a full list of NPS found in the thread titles of this study. There were also discussions about branded NPS in which the actual psychoactive component was concealed or unknown, which resulted in elaborate speculations about the content: “Vendor will not reveal the molecule”. / “I have used both chemicals and believe they are different. ‘Sunshine’ is not Methylone either”. It was very common to compare the NPS discussed with traditional counterpart drugs or previously occurring NPS and rate them accordingly. Another recurring topic was how and where a substance was acquired: “I really want to try this, could anyone post where to get it?” to which another user responded: “Hello, you have an email”. Selling drugs via the forums or linking to sites that offered drugs was officially not allowed, so these discussions were mostly moderated or continued nonpublicly: “Can someone pm [Personal Message] me a vendor in the US?” Different vendors were nevertheless mentioned in talks about their offered products or in discussions related to price, shipping, and the overall evaluation of the vendors’ service. General discussions about NPS availability were also found, which often included descriptions of where the NPS was encountered, such as online or in real life. In addition, the reports of availability were closely linked to discussions of the legal status in different countries: “Canada’s drug act does not list Ethylphenidate, and no analog law for Methylphenidate exists so you should be legally safe here”. Potentially legal consequences of possession or purchase of NPS were also mentioned.

Table 2 The NPS found among the thread titles Full size table

Other more in-depth substance talk involved chemistry and pharmacology. Users speculated about how substances were built molecularly and how specific chemicals interacted with the brain and body to produce certain effects, for example, “Both stereoisomers are most likely active (as with amphetamine). In that case, it’s a matter preference: dopaminergic or noradrenergic effects. Choose for yourself”. The origin and history of certain NPS were discussed as well. Furthermore, users talked about how the use of certain chemicals could have contraindications with both traditional substances and other NPS. Related to pharmacology was the topic of tolerance from repeated use of the same substance and cross-tolerance between chemically similar substances. Toxicity was also found to be of interest for the users, and many discussions focused on theoretical speculation of a substance’s overall harm potential: “The neurotoxicity of 4-Fluoroamphetamine derive from the release of large amounts of serotonin from the neuron, as well as general inhibiting effects of neuronal processes”. Moreover, discussions focused on the exterior appearance of different NPS and the assessed purity. Users described if the NPS was produced in the form of a pill, powder, or other. The users gave detailed reports on appearance, feel, smell, and taste. They also assessed the identity, quality, and purity from the appearance, for example, “My powder has a distinct benzene-like chemical odor and a blueish/greenish color. Unlike former yellowish odorless batches, I think this one might have impurities”.

Dosage and administration

This theme consists of topics related to circumstances surrounding the administration of NPS. Dosage was found to be a widely debated topic of discussion. Many opinions and estimations about dosing and re-dosing were stated. Users also asked for advice on specific dose recommendations with regard to individual traits as previous experience, body weight, built-up tolerance of the drug, etc. They also speculated about how the dose could affect the experience and intensity of effects and suggested different doses for specific purposes, for example, “I think 15 mg is perfect for moderate effects - great for watching movies! Then at 30 mg the visual impressions and euphoria increase dramatically”. The route of administration was given much attention. Users described several different ways in which different NPS were taken, such as nasally, intravenously, and orally. Opinions about the best way to ingest a specific substance were very common: “I don’t recommend insufflation and the taste is awful. Rectal administration is recommended for a rapid onset”. Technical talk about things such as do-it-yourself smoking devices and weighing and purification of a substance were found: “Did you wash the crystals before recrystallization? If so, which solvent(s) did you use?” Taking a specific NPS in combination with other drugs and how the different effects would interact with or supplement each other were also discussed: “I want to experience Methylone, Mephedrone and MDPV in one go. Who has tried this or can give advice on dosage?” The circumstances and surroundings in which the drugs were administered were shared among users. They also asked for, or proposed to others, several settings and recreational activities: “How would this substance suit a nightclub setting?” Users also discussed their expectations of the upcoming experience of NPS and their mood or state of mind when taking the drug. They were suggesting and sharing different purposes of using drugs, for example, study aid, recreation, self-medicating, curiosity, and personal development.

Subjectively experienced effects

This theme was the most prevalent and summarizes discussions about subjective and self-experienced effects induced by a wide variety of NPS. The effects were discussed in great detail and with precision. Many initial or onset effects were described. Also, the primary effects and positive aspects of an experience were shared thoroughly: “I felt a boost in confidence and was more social, verbal and energized. I was also more curious and present.” Potency and duration of effects were central and recurring topics in this theme. Specification of the time at which different phases of the experience occurred was mentioned. The discussions of effects were found to consist of physiological, emotional, and cognitive aspects of the experience. Also, users were talking about perceptual and sensory alterations. In addition to the positive effects, many side effects or negative experiences were shared: “I used this substance for the first time and experienced chest pains and aches all over the body”. Residual effects or aftereffects were also given attention in the discussions. Users who had not tried a specific NPS asked others to share their experienced effects. There were not many debates or arguments found among the effect discussions; instead, it appeared that the whole community contributed to complete a picture of the overall effects: “I also experienced that the ‘magic’ of Methoxamine decreased over several successive trips”. The first posts about experiences with a novel substance were often scientifically depicted: “T + 0:00 2 mg allergy check intranasally. T + 0:22 Calibration dose 15 mg sublingually. T + 1:10 Subject experiences euphoria equivalent to 40 mg 4-methylephedrone but less stimulation. T + 2:10 Subject confirms a return to baseline.” References to, and comparisons with, traditional substances and their effects were made to explain the experience to others: “4-fluoroamphetamine definitely feels like MDMA. The empathy is there and I’m socializing and experiencing a pleasant wellbeing. The stimulation and sharp focus also reminds me of amphetamine”. In addition, if the NPS in focus had a traditional counterpart substance, it was often used as point of reference to evaluate the effects at large. Rating and evaluation of effects in general were found to be a very common topic: “I love it! Although it does not have the intensity of MDMA or Mephedrone, it reminds me of their chemicals qualities. This substance is deeper and more multifaceted than amphetamine”. They also discussed the impact of the experience on everyday life: “6-MAPB changed my worldview and helped me in a tremendous way”.

Support and safety

This theme emphasizes that the discussions involved social support and community help with drug-related issues of concern. Users often asked each other for specific advice on how to prevent or minimize harm. They also expressed the need for support with drug-related problems, to which other users would respond: “I advise you not to take it under those circumstances because serotonin will be released like with MDMA”. It was also found that users shared practical tricks and theoretical knowledge with one another to reduce potential problems such as sleep deprivation, contraindications, and the misidentification of substances. Experienced users were asked to verify the authenticity of substances by providing photographs or appearance descriptions. Furthermore, general caution and harm reduction was proposed throughout the forums: “At this forum we advocate taking a break of at least one month between uses, which applies to 5-MAPB as well”. Individual users who suspected a dangerous aspect of using a NPS cautioned the whole community. The first users who ordered and used a previously unknown NPS shared their firsthand experience of immediate risks and hazards with the rest of the community. For example, several early warnings about substances or combination of substances that constituted a perceived risk were found: “Purple Wave of any kind is toxic… do not purchase it, you will mess yourself up”. / “Be aware of this combo! Some people have had strong reactions to this”. Less immediate warnings of potential side effects accumulated in the threads of discussion as more users started to report back about the drug: “I warn you: the residual effects are bad if you binge on it for a while and abruptly stop”. The abuse potential of different drugs was also discussed: “In my experience it has highly addictive properties”. Furthermore, if the first users of an unknown NPS experienced it as safe and reliable, it was reported in the thread as well. Warnings also included notions of bad batches of a substance or scamming vendors.

Discussions were oriented towards acute help and emotional support to users who were online to ask for guidance while intoxicated with fearful or bad reactions: “Is anyone online because I need assistance with an ongoing anxiety attack?” Different coping strategies were suggested by fellow users: “Relax, you will be fine. Put on a movie or occupy yourself by talking to friends.” Long-term problems like addiction and withdrawal were also topics that emerged. Users asked about abuse problems, and others were being supportive or offered their experience on how to solve them. Also, several recovery reports were shared publicly to other users, who responded with encouraging comments or grateful remarks.