The Besins Australia site has this info on their Oestrogel patient info:
"Generally speaking, you should wait until one hour
after application before washing your skin, applying
other skin care products or being in close contact
with your partner.1
Skin products such as moisturisers and sunscreens
can be applied 1 hour after application of Estrogel.
This is also when skin can be washed or immersed
in water (e.g. bathing or swimming)"
I always carry medication in my hand luggage, just in case check-in bags go astray!
