Will a VPN slow my internet connection?
When you connect to a VPN server, your usual connection get's encrypted and runs through a server of your choosing. These are the two factors that can influence the speed of your connection.
Simply said, when you encrypt your connection, your connections slows down. And when the encryption gets heavier, the speed of your connection get's lower.
Another factor that could influence the speed of your connection, is the distance between you and the server you choose. Say you are in Germany and want to connect to a VPN server. If you choose a server in Germany, your connection is bound to be faster than through a USA based server.