The IB that is experienced with retinoids is most commonly referred to as the skins initial "purge". LIke you, I am going along with the idea that since you have already gone through one retinoid purge, there shouldnt be much of a problem with switching to another - because of the fact that all retinoids work in similar manners. The only thing I could really say might happen is that bumping up strenghts carries with it a chance for increased irritation/redness, but as a far having a whole new set of breakouts doesn't seem likely.

Good luck!

Thanks for the reply, random1

So I got switched to Differin 0.1% cream. I tried asking for Tazorac (Zorac in the UK) but was told that even though he found it in the database, it's not in their guidelines as something to give out for acne and therefore he wouldn't give it to me as he has no experience with it! I guess it's just not used in the UK for some reason, which really sucks as from reading around here and other websites it sounded like it'd be the closest to the Retin A.

I'm kinda worried about switching to Differin cream now - I was using 0.025% Retin A gel originally and I keep reading that Differin is not as strong as Retin A? Perhaps if he'd given me the 0.3% Differin gel it would be of similar effectiveness but at the moment I'm feeling kind of shady about the 0.1% cream. I started out with awful inflamed cystic acne all along my jawline, it was so bad it would be physically painful and I'm really scared it could go back to that! My GP told me to go back if it isn't working and that I would know by 3 months, but I feel like it's kinda late by then :/

Does anyone have any experience of switching between these two like this, or know what kind of reaction I can expect from my skin? Since the Retin A 0.025% was discontinued I switched to the 0.001% before that too was discontinued, and just that switch between the 2 stengths of Retin A has been enough to cause more frequent (although still manageable) breakouts