Been using this for a few weeks now. It's supposed to be applied before applying moisturizer. It's liquidy consistency may be a plus or minus depending on you: it certainly makes it easier to spread over a larger area. Haven't noticed any irritation, which is a plus, despite its (natural) acid ingredients. No complaints about smell, either. But, more encouragingly, it seems to be lessening my forehead lines, albeit more slowly than I'd like :)