1) Antacid 2) Antagonistic 3) Antidotal 4) Antiphlogistic 5) Compensative 6) Compensatory 7) Countervailing 8) Offsetting 9) Opposing 1) Antacid 2) Antidotal 3) Antiphlogistic 4) Compensative 5) Compensatory 6) Corrective 7) Countervailing 8) Offsetting 9) Remedial 
• (n.) One who, or that which, counteracts. • (a.) Tending to counteract.
Coun`ter·act'ive adjective Tending to counteract. 
[adj] - opposing or neutralizing or mitigating an effect by contrary action
counteractive Opposing or neutralizing or mitigating an effect by a contrary action.
adjective opposing or neutralizing or mitigating an effect by contrary action