An almost completely reliable truth serum, Fast-penta is a commonly-used tool of ImpSec, the Barrayaran intelligence agency, and of numerous of its allies and enemies, too.
The drug itself relaxes physical tensions, as well as mental and emotional inhibitions. It is not so much that it compels honesty, as that it compels docility and helpfulness – which, in the hands of a skilled interrogator, amounts to about the same thing.
Artificial immunity to it is sometimes given to operatives by their agencies, and more rarely, some people have naturally idiosyncratic reactions to it, in which the effects are more similar to those of ecstasy or LSD – Miles Naismith Vorkosigan is one of these.
Related drugs: Synergine
One of the more effective Truth Sera, Niathol is usually administered by syringe in quite small quantities – rarely more than 2cc’s, except for the largest people.
This is because it doesn’t take much more of it to kill. Niathol is stored frozen, but cannot be refrozen safely, and thus any remaining unused quantities of it must be disposed of carefully – molecular dispersal is usually considered the minimum degree of care.
Related Drugs: Alphanella seeds.
Penzerol is a strong and mostly effective truth serum when used on humans. Only those with unusually strong wills – or alien DNA – can resist its effects.
Of course, it does have a nasty side effect of potentially causing permanent brain damage, and as with most drugs, too great a dose is fatal.
Unusually, it is part of a suite of other drugs intended to be used together, notably sedatives which help prevent the heightened physical responses that interrogation so often entails from getting in the way of actually obtaining information.
Related Drugs: Red Skeezix
One of the more effective truth drugs out there, TC-6 is typically used only by government agencies for interrogations. Administered via direct injection, it leaves those it is administered to able to respond intelligently, although it will make most people somewhat literal-minded. It will also leave them utterly without volition of their own and thus unable to lie.
It is possible to resist the effects of TC-6, although to do so requires considerable experience with truth drugs, and a certain amount of psychological conditioning, as well.
Very few people have this conditioning, however, so the drug remains useful. A single does will last for several hours, although the drug is known to have certain side-effects regarding impaired cardiac function in some people – potentially fatal side-effects – and there is no test to detemine ahead of time who will suffer them.