AH-7921 (3,4-Dichloro-N-([1-(dimethylamino)cyclohexyl] methyl)benzamide) is an N-substituted cyclohexylmethylbenzamide classified as an opioid analgesic with high addictive liability. The compound acts as an agonist of μ-opioid receptors, although at high doses it can also stimulate κ-opioid receptors. In animal studies, AH-7921 produced typical morphine-like actions, i.e., antinociception, respiratory depression, sedation, miosis, inhibition of gut propulsion, and lowered body temperature, with a potency almost equipotent to that of morphine. There is limited information available on the routes of administration and the doses of AH-7921 used. The compound is taken orally, nasally, by smoking, and, less commonly, by intravenous injection. Minimal oral effective doses for complete pain suppression by AH 7921 are 1.25 and 13.8 mg/kg for canine and rhesus monkey, respectively.

4-Methoxymethamphetamine (PMMA, para-Methoxymethamphetamine) is a stimulant and psychedelic drug closely related to the amphetamine-class serotonergic drug para-methoxyamphetamine (PMA). Little is known about the pharmacological properties, metabolism, and toxicity of 4-Methoxymethamphetamine. Because of its structural similarity to para-methoxyamphetamine, which has known toxicity in humans, it is thought to have considerable potential to cause harmful side effects or death in overdose. In the early 2010s, a number of deaths in users of the drug MDMA were linked to misrepresented tablets and capsules of 4-Methoxymethamphetamine. In 2010–2013, a cluster of 29 fatal poisonings related to the toxic designer drug 4-Methoxymethamphetamine was revealed in Norway. The toxicity of PMMA is regarded as substantially higher than for amphetamine, methamphetamine, and MDMA, as indicated by 131 fatal and 31 nonfatal poisonings associated with the abuse of 4-Methoxymethamphetamine worldwide. The toxicity of 4-Methoxymethamphetamine is positively correlated with the 4-Methoxymethamphetamine dose and the blood drug level, but the existing literature indicates that certain human subjects may have an increased risk of 4-Methoxymethamphetamine toxicity. 4-Methoxymethamphetamine, like PMA most likely acts as a selective serotonin releasing agent (SSRA) with weak effects on dopamine and norepinephrine transporters. However, relative to MDMA, it is considerably less effective as a serotonin releaser with properties more akin to a reuptake inhibitor in comparison. It evokes robust hyperthermia while producing only modest hyperactivity and serotonergic neurotoxicity, substantially lower than that caused by MDMA.