effectiveness

Noun

• capacity to produce strong physiological or chemical effects
  • the toxin's potency
    
  • the strength of the drinks
    

• power to be effective; the quality of being able to bring about an effect

Related words

• Synonyms: 
  potency , strength , effectivity , effectualness , effectuality
• Antonyms: 
  ineffectiveness , ineffectualness , ineffectuality