This is really gentle and not as irritating as other growth formulas I've used but it still works so well!

I bought this as I tend to get red/purple discolouration on my eyelids from other serums (eg Revitalash, which works phenomenally well otherwise). I haven't reacted to it and I like that the application is with a sponge and mascara wand - so much easier than the other serums out there. It does seem to have darkened the roots of my lashes (usually see-through blonde) to a dark brown colour but it's not suddenly made them look tinted. It has maintained the length of my lashes that I achieved from Revitalash; as I'd used that first, though, I can't tell whether this product would also have achieved the length itself.