Sunscreen with insect repellent

Insect repellent can affect your sunscreen. Personal insect repellents containing, N-Diethyl-m-toluamide (DEET) can reduce a sunscreen’s effectiveness by approximately a third.

Combination sunscreen/insect repellent products are SPF-tested after the DEET has been added, so the product in the package does indeed have the SPF that is stated.
However, you will need to reapply the sunscreen more regularly than the insect repellent – in which case it is probably a good idea to use sunscreen without insect repellent.