[SiNaGaMeR]

PHP Code:

    if(hp <= hpp)
    {
        KillTimer( Player[playerid][DrugTimer] );
        
        Player[playerid][OnDose] =0;
        format(msg, sizeof(msg), "* Your health has set to %f ", hpp);
        SendClientMessage(playerid, -1, msg);
        
        //return 1;// Remove this line or disable it!
    }else{
        SendClientMessage(playerid, -1, "Falied to stop timer. and enter if statment");
    }
    
    SetPlayerHealth(playerid, (hpp + 5.00) );
    
    return 1;
} 


Maybe with disabling return that I said your code will be fixed.