You Do Need power plug adapter while traveling from Guadeloupe to United Kingdom (UK).

Here is Why You Need An Adapter

The outlet and plug type used in United Kingdom (UK) is G and in Guadeloupe are C and E. This is how they look like.

Guadeloupe

In Guadeloupe, outlets of type C and E are in use.

Type C

Type E

United Kingdom (UK)

In United Kingdom (UK), outlets of type G are in use.

Type G