[8] Drugs known to be σ-agonists include cocaine, morphine/diacetylmorphine, opipramol, PCP, fluvoxamine, methamphetamine, dextromethorphan, and berberine.
In animal experiments, σ-antagonists such as rimcazole were able to block convulsions from cocaine overdose.
The abundant neurosteroid steroid hormone DHEA is an agonist at sigma receptors and along with pregnenolone could be endogenous agonist ligands; opposed by sigma antagonistic activity from progesterone.
[citation needed] Some σ-receptor agonists—such as cocaine, a weak σ-agonist—exert convulsant effects in animals.
In 2007, selective σ-receptor agonists were shown to produce antidepressant-like effects in mice.