This lash extender promises to condition lashes, make it so you need to use less mascara (therefore you'll get more bang for your buck), allow your lashes to grow to their full potential, and prevent splitting.
Since (I believe) it is impossible to grow your lashes past their full potential, it would be unrealistic to expect false-looking lashes after using this for an extended period of time. However, I've read that each person's lashes can only reach a certain length, and that length is predetermined by genetics (but please correct me if I am incorrect here). For me, I did notice my lashes staying in longer and feeling softer and stronger when I don't wear mascara. However, it doesn't dry completely clear, so I don't recommend wearing this product alone. I've tried it under every mascara I own (including some that dried up) and it works nicely with a variety of formulas.
The hardest part of getting used to this lash conditioner is that you're not supposed to let the conditioner dry before you go in and apply mascara (so it still needs to be a little wet and you have to work fast). It just took me a few tries to get the technique just right. I think the price is just right ($16) and the ingredients list is impressive since almond oil is known to condition lashes, but actually using almond oil would probably not work well under mascara ;)
Ingredients: Water, Algae Extract, Beeswax, Stearic Acid, Glycerin, Carnauba Wax, Hydroxyethylcellulose, Panthenol, Hydrolyzed Wheat Protein, Oleic Acid, Vanilla Tahitensis Fruit Extract, Sweet Almond Seed Extract.I won't say this item is necessarily "essential" for everybody but I will say it is a fantastic addition to my daily routine and I will repurchase it because of the benefits and the fact that my lashes definitely seem to be longer and fuller on their own. I highly recommend it.
FTC: I was sent the Jane Iredale PureLash Lash Extender & Conditioner to review. However, I always give my honest opinion on products and will not compromise my own integrity for the sake of a product's reputation. I am not being compensated for this review and my ties with Jane Iredale are informal, but friendly (as in, I haven't signed a contract with them or anything). You can buy this product here or anywhere that Jane Iredale products are sold!