It acts as a partial agonist of the opioid receptors, with mixed agonist and antagonist effects.

U-50488 is a drug which acts as a highly selective κ-opioid agonist, but without any μ-opioid antagonist effects.

Lisuride (primarily dopamine agonist, but 5-HT antagonist effects as well)

Tamoxifen and raloxifene are SERMs, drugs that have divergent estrogen agonist and antagonist effects in different target organs.

However, when dynorphin A was injected into the intracerebroventriulcar (ICV) region of the brain, it had an antagonist effect on morphine-induced analgesia.

Lignans are thought to have estrogen agonist and antagonist effects as well as antioxidant properties.

Mirtazapine (trade name Remeron) is a tetracyclic antidepressant with 5-HT antagonist effects and strong anti-emetic properties.

Also, progesterone and DHEA have antagonist effects on the GR.

Scopolamine, also known as levo-duboisine and hyoscine, sold as Scopoderm, is a tropane alkaloid drug with muscarinic antagonist effects.