Obliviol is a drug that induces sensory deprivation. The basic formula is effective in all Terragen primates. There are also several variants that work on non-primates (though most are formulated for mammals). Variants are prefixed with old-style Greek letters — the base formula is α-Obliviol, β-Obliviol works on cetaceans, γ-Obliviol is formulated for canids, and so on. The drug is a depressant that suppresses neurotransmitter activity in key areas of the brain — particularly the optic and auditory lobes and the part of the hindbrain that processes olfactory signals (a side effect of the latter is a general dampening of emotions). Obliviol is not psychologically addictive due to the lack of a "high," but it is both tolerance producing and mildly toxic. There are confirmed cases of death by overdose. A single does remains active for about an hour in a typical hu metabolism.
Obliviol is a controlled substance in much of the Civilized Galaxy because of the potential for abuse; its use in crimes such as kidnapping, rape and murder has been verified on numerous occasions. A few particularly jaded bionts have been known to use obliviol as a recreational drug; the lack of sensation often appeals to those who suffer from a surfeit of it. There are also instances of the drug being administered as a form of torture or to control violent criminals. The most common use is as a meditation tool for mystics. Denathi Adepts frequently take obliviol when learning to control their "psi-nano" abilities, so the drug can be obtained legally on their worlds. Even so, Denathi merchants are loathe to sell obliviol to non-Denathi.