Heavy alcohol consumption over a period of years can lead to "reverse tolerance".

Reverse tolerance or sensitization can also occur.

The various neurotransmitter systems and subsystems may reverse tolerance at different speeds, thus explaining the prolonged nature of some withdrawal symptoms.

In rodent studies, repeated amphetamine treatment produces robust behavioral sensitization (or reverse tolerance) to some of the drug's effects.

Conversely, some researchers have reported observing the opposite effect in animal models: repeated amphetamine use can produce reverse tolerance or sensitization to the psychological or locomotor-stimulating effects of the drug.

While all three drugs retained their effectiveness over two weeks, etizolam actually started to become more effective than the other benzos from to 2 weeks to 4 weeks (reverse tolerance in a way).

In regards to safety in terms of addiction, unlike more traditional hallucinogens like LSD and mescaline, salvinorin A affects kappa Opioid receptors and is noted for its reverse tolerance.

When multiple doses of etizolam or lorazepam were administered to rat neurons, lorazepam caused downregulation of alpha-1 BZD sites (aka tolerance/dependence), while etizolam caused an increase in alpha-2 BZD sites (aka reverse tolerance to anti-anxiety effect).

Reverse tolerance or sensitization is the phenomenon of a reversal of the side-effects from a drug, the reduction of insensitivity caused after drug tolerance has been established, or, in some cases, an increase in specific effects of a single drug existing alongside a tolerance to other effects of the same substance.