Lash Serum is something that I always have one in rotation. I notice some effects (nothing dramatic like people get with those prescription drugs) with almost of the one I have tried but only repurchased L'Oreal (because it wasn't too pricy, didn't sting or look like booger once dried). The newest one under my belt is the Shiseido Full Lash Serum. It's funny that on their website they call it Lash and Brow Serum, because that's what I tend to use if for.
The Shiseido serum has a semi-opaque gel texture (very much like the discontinued L'Oreal) that's easily dispensed with the doe-foot applicator. It's light weight, gentle and doesn't cause any discomfort when applied closed to lash line. I have been using it right after cleansing/toner and before everything else, on my brows as there is a bald patch from stress pulling. After two months of almost daily uses, the area now looks well-conditioned and the bald patch also grew back. I didn't end up with a new lush pair of caterpillars but I am all good.
Let's look at the very short ingredients (with break down in the parentheses)
Ingredients: Water, Dipropylene Glycol(humectant/solvent), Butylene Glycol (humectant/solvent), Sorbitol (humectant/thickener), Alcohol(solvent/giving lightweight texture), Polyvinyl Acetate (glue? thickener), Glycerin (humectant), Carbomer (gel that suspend other ingredients), Phenoxyethanol (preservative), Ethylhexylglycerin (conditioning), Methylparaben (preservative), Polyvinyl Alcohol (eye lubricant), Potassium Hydroxide (a base for pH adjustment), Arginine (some amino acid), Xanthan Gum (thickening agent), Zizyphus Jujuba Fruit Extract (red date), Simethicone (anti-foaming agent), Trisodium EDTA(preservative), Tocopherol (Vitamin E).
So beside the three ingredients in bold (which are all kind of far down the ingredient list, after fillers and even preservative) which might stimulate hair growth and condition the lashes/brow hair. This serum is consist of mostly humectant and other ingredients that form the pleasant, light weight texture. I find it interesting they didn't include the no-brainer panthenol in the mix but maybe the red date and arginine are potent enough?
My experience with the serum feels nice on the brow is mostly because, I don't put anything skincare product on my brow otherwise. As for the bald patch recovery, it would have grown back even I didn't use anything. I have read that their cosmetic scientist said the combo works but it takes at least three months. It takes me much shorter time to grow a unibrow, and all you need to do is hide my tweezers.
Anyway, the whole step feels like a nice little treat and pampering step of skincare. I don't find Shiseido Full Lash Serum to be any better than the drugstore ones (I got two, one with Hello Kitty another with Tweety packaging) so I won't repurchase.