Thank you Penguin. Some of the HRT products I've had over the years do say not to store above a certain temp, 25C comes to mind. I've not taken the Oestrogel out of the UK, but we are in a part of the country that gets extremes of temps & it has been way up in the 30s here at times this summer & last, though the cupboard I keep my HRT in is relatively cool & dark, but of course I can't be sure how hot it got.
I'm a bit stumped tbh as the gel from the same canister went on smoothly as usual yesterday. That said, I had no sense of having had any extra oestrogen from that application, so wonder whether something has happened to degrade it in the time since it was first opened. The dodgy canister is relatively light, so probably not much left in it, so I'm binning it without too much guilt & starting on a new one tomorrow, also from 2021 but never opened & more than a year to go on the expiry date. Fingers crossed.
Would be interested to know if anyone else has had Oestrogel behave like this though.