Is this product needed to use the monitor? I.e. If I purchase monitor do I need these?

You will need to use lancets to poke the small hole in your finger to get the blood droplet. Lancets are generally universal, so any lancet should work.

Do you sell the lancing device on its own?As I do not require the ketone reader/meter or strips.

Yes. Here is a link to the lancing device. https://bestketonetest.com/collections/ketone-meter-strips/products/truedraw-lancing-device

Are the True Plus lancets for both ketone and glucose testing?

Yes. The lancets work in the lancing devices to allow you to get the required blood. This is used for both ketone testing and glucose testing.

Are you required to change lancet following each test?

For hygiene reasons you should. Does everyone change it after each test? No. If you are sharing you most certainly should.