Ich nehme an du willst erst die Health voll machen, und dann die Armour, oder?
Dann so:
ocmd:smokeweed2(playerid, params[])
{
    if(PlayerInfo[playerid][sWeed] > 0)
    {
        new Float:pHealth, pArmour;
        GetPlayerHealth(playerid, pHealth);
        GetPlayerArmour(playerid, pArmour);
        if(pHealth == 100.0 && pArmour == 100.0) return SendClientMessage(playerid, COLOR_WHITE, "* Du brauchst kein Weed mehr.");
        if(pHealth > 100.0 || pArmour > 100.0) return SendClientMessage(playerid, COLOR_WHITE, "* Du bist ein Cheater.");
        if(pHealth + 25.0 <= 100) SetPlayerHealth(playerid, pHealth+25.0);
        else
        {
            SetPlayerHealth(playerid, 100.0);
            pArmour += pHealth-75;
            if(pArmour > 100.0) pArmour = 100.0;
            SetPlayerArmour(playerid, pArmour);
        }
        PlayerInfo[playerid][sWeed] -= 2;
        new sendername[MAX_PLAYER_NAME];
        GetPlayerName(playerid, sendername, sizeof(sendername));
        GiveNameSpace(sendername);
        SaveDrugs(playerid);
    }
    else
    {
        SendClientMessage(playerid, COLOR_WHITE, "* Du hast kein Weed mehr.");
    }
    return 1;
}