Clogged pores: am I over-moisturising, or dehydrated?

It's hard to say. None of these things are technically wrong - dehydration can lead to overproduction of oil/breakouts, residue pileup from over-moisturizing can break you out, and cream based tretinoin can too. It all depends on your skin and what products you use. What's your routine like? What has changed since you started tret? What is your climate like - mostly is it extremely humid or extremely dry?

If I had to guess based on what's common for most people, I would not guess that your skin is breaking out from moisturizer piling while on tret given how dehydrating it is, but depends on what moisturizer you're using too.

What are thoughts on not moisturising at night after applying tret (since it's in a cream formulation anyway)?

Not sure what the cream formulation of your tretinoin has to do with why you would discontinue moisturizing - could you explain a little further? Having a creamy texture doesn't make your tret moisturizing, it's just the carrier medium for the product to increase spreadability. Personally I think not moisturizing entirely after tret would be a mistake for most people.

/r/tretinoin Thread