Review title is Not Sure If This Zenlash Eyelash Growth Serum Does Much! [SEP] I purchased this because it was suppose to be irritation-free. I have allergies and my eyes get irritated quickly. This one stings. I don't particularly like it for my lashes but I wanted to something to boost my brows since I have some sparse patches. It doesn't irritate my eyes there. It's just  not what I expected: I can't say that it has done a lot for lashes or brows either.