Is Isotretinoin effective for rosacea?

The answer is not that simple. It may work if you have papules and pustules and if you have oily skin, but it varies case per case. And you should give it at least a few months, worsening is common at the beginning. It is important to evaluate you properly and see what is the presentation to give the proper advice. "Nothing works" usually always has a reason and it should be properly investigated. Just a few thoughts:1) Did you look through your skin care regimen with your derm to see if it is appropriate for rosacea?2) Are you using sunscreens daily, even when "not going out"? Sunscreens are a must in rosacea.3) When you say that lasers do not work, I would also be more specific about what type of lasers you have used. Some lasers are used in rosacea but are not very specific (IPL, BBL), others work specifically on the vessels (for example PDL). In general, lasers are highly effective for redness, but they should be used properly and you need a series of treatments with adjusting settings. 4) Oftentimes underlying problems should be investigated (thyroid, gut).
Good luck with your healing process!