Ethylmethylthiambutene is a potent analgesic compatible with morphine. It possesses addiction liability similar to that of morphine.

Psilocybin is a naturally occurring psychedelic prodrug compound produced by more than 200 species of mushrooms, collectively known as psilocybin mushrooms. Once ingested, psilocybin is rapidly metabolized to the psilocin, which then acts on serotonin receptors in the brain. Psilocybin was identified as the active hallucinogenic compound in magic mushrooms in 1959, but humans have used assorted psilocybin mushrooms in religious ceremonies since prehistoric times. In the 1960's psilocybin was marketed for use as a treatment for various psychoses, however, it was withdrawn from the market when the regulatory environment changed. Recently there has been as renewed interest in studying the medicinal uses of psilocybin for treatment of anxiety, depression, migraine headaches, addictions, and other neuropsychiatric conditions.

Etoxeridine (Carbetidine or Wy2039), a piperidine derivative, is a narcotic analgetic.

Lysergide (LSD) is a semi-synthetic hallucinogen and is one of the most potent drugs known. Recreational use became popular between the 1960s to 1980s, but is now less common. LSD was first synthesized by Albert Hoffman while working for Sandoz Laboratories in Basel in 1938. Some years later, during a re-evaluation of the compound, he accidentally ingested a small amount and described the first ‘trip’. During the 1950s and 1960s, Sandoz evaluated the drug for therapeutic purposes and marketed it under the name Delysid®. It was used for research into the chemical origins of mental illness. Recreational use started in the 1960s and is associated with the ‘psychedelic period’. LSD possesses a complex pharmacological profile that includes direct activation of serotonin, dopamine and norepinephrine receptors. In addition, one of its chief sites of action is that of compound-specific (“allosteric”) alterations in secondary messengers associated with 5HT2A and 5HT2C receptor activation and changes in gene expression. The hallucinogenic effects of LSD are likely due to agonism at 5HT2A and 5HT2C receptors. LSD is also an agonist at the majority of known serotonin receptors, including 5HT1A, 5HT1B, 5HT1D, 5HT5A, 5HT6 and 5HT7 receptors. During the 1960s, LSD was investigated for a variety of psychiatric indications, including the following: as an aid in treatment of schizophrenia; as a means of creating a "model psychosis"; as a direct antidepressant; and as an adjunct to psychotherapy. LSD is listed in Schedule I of the United Nations 1971 Convention on Psychotropic Substances.

Racemoramide (also known as Moramide) is an opioid analgesic with a central structural action. In clinical trials, Racemoramide shows a strong analgesic action and low toxicity.

Alpha methyltryptamine (AMT) is a tryptamine (indole ethylamine) derivative, which was developed in the 1960's by Upjohn with the intention for use as an antidepressant. It was used in Russia under the trade name Indopan for the treatment of Bipolar disorder and some form of depression, but currently not being produced because of serious side effects. In the 1990's, alpha-methyltryptamine became regulated as a Schedule I controlled substance in the United States. Pharmacologically, AMT has high affinity for the serotonin (5-HT) transporter, a number of 5-HT receptors, and potently inhibits reuptake of monoamines dopamine, 5-HT, and norepinephrine reuptake. AMT is also a monoamine oxidase A inhibitor that conceivably could contribute to its pharmacological effect and this drug also the most potent inhibitor of semicarbazide-sensitive amine oxidase (SSAO).

Mephedrone (4-methylmethcathinone) is a β-ketoamphetamine belonging to the family of synthetic cathinones, an emerging class of designer drugs known for their hallucinogenic and psychostimulant properties as well as for their abuse potential. Mephedrone is a stimulant of dopamine (DA) release and blocks its reuptake through its interaction with the dopamine transporter. Furthermore, it has some affinity for various 5-hydroxytryptamine (5-HT) receptor subtypes. Neurotoxic effect of mephedrone on 5-HT and DA systems remains controversial. Although some studies in animal models reported no damage to DA nerve endings in the striatum and no significant changes in brain monoamine levels, some others suggested a rapid reduction in 5-HT and DA transporter function. Persistent serotonergic deficits were observed after binge like treatment in a warm environment and in both serotonergic and dopaminergic nerve endings at high ambient temperature. Oxidative stress cytotoxicity and an increase in frontal cortex lipid peroxidation were also reported. Despite the re-classification of mephedrone as a Class B restricted substance by the United Kingdom and restrictive legislation by the United States, international policy regarding mephedrone control is still developing and interest in synthetic amphetamine-like drugs could drive the development of future mephedrone analogues.

Parafluorofentanyl is a selective mu-opioid agonist, an analog of fentanyl, developed by Janssen. The drug was not developed for human use but is produced and abused illegally.

Norlevorphanol is the levo-isomer of 3-hydroxymorphinan (morphinan-3-ol). It is is an opioid analgesic of the morphinan family. Norlevorphanol is a Schedule I controlled substance (opiate).