This problem generally decreases with increased potency and smaller doses. Not all vitamers possess exactly the same vitamin potency, per mass. IC is commonly used as a measure of antagonist drug potency in pharmacological research. A correlation exists between average clinical potency and affinity of the antipsychotics for dopamine receptors. Adjunct medications are an umbrella category of substances that increase the potency or "enhance" antidepressants. Different types of local anaesthetic drugs vary in their potency and duration of action. Heroin is widely preferred because of increased potency. It manifests as tendency, karmic impulse, subliminal impression, habitual potency or innate dispositions. This is due to the extreme potency of the tetanospasmin toxin. A purported reason was the appearance of high potency cannabis. Extensive research has been conducted to determine equivalence ratios comparing the relative potency of opioids. The Romans likewise claimed that it increased sexual potency. It also acts as a dopamine releasing agent with around 10-fold lower potency. IGF-1 activates the insulin receptor at approximately 0.1 times the potency of insulin. Glucocorticoid potency, duration of effect, and the overlapping mineralocorticoid potency vary.