The best replacement for agonist is antagonist.

The best alternatives to agonist are rated as following:
★★★★★  antagonist
★★★★  antagonist muscles
★★  prime mover
★★  antagonist ivf
★★  ligand
★  partial agonist
★  atheist
★  blocker
★  antagonist neurotransmitters
★  inhibitor
★  antagonist muscle
  antagonist neurotransmitter
  direct agonist
  antagonist receptors
  levodopa
  beta 2 agonist
  receptor antagonist
  beta antagonist
  an antagonist
  arch enemy
  opioid antagonist

Your alternative for agonist is not listed? Suggest!
Speaking about agonist, one probably shouldn't forget about ssri.

Other search terms related to agonist and their ratings are:
★★★★★ ssri
★ corticosteroid
You have in mind a companion for agonist and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of agonist in all years. Click on graph for more.
agonist
antagonist
antagonist muscles