I've been using this for years. I usually use it as a base coat under nail colour, I find that it really keeps my nails from yellowing. My major gripe is that by the time I'm halfway through a bottle, it thickens to the point of being useless. At this price, it hurts to throw away half of each bottle. From the reviews here, I will have to go with the original Nail Envy next time, I'm just a little worried about nail yellowing due to the formaldehyde in that one. FYI Sensitive & Peeling is formaldehyde free.
Update: I've switched to the OPI Natural Nail Base Coat. It dries super fast and doesn't thicken over time. I'm done with Nail Envy continued >>

I picked and bit at my nails for over 15 years until I found Original Nail Envy. It worked almost instantly, and kept my nails gorgeously long and strong - enough that I didn't have to manicure them for my Wedding in 2007.
I have also suffered from eczema most of my life and I put the increased itching, inflamation and irritation down to the stress of planning my Wedding. The irritation was on my eyes, scalp, arms - and where I scratched, it got worse.
It's only now I'm watching my health more closely and removing chemicals where I can, that when I ran out of (Original) Nail Envy I noticed a marked improvement!
This is down to the Formaldehyde contained in the Original formula - after all, it is used to preserve dead bodies and tissue so I understand the way it works. Unfortunately, it appears I am allergic.

I've stopped using the Original formula, and moved to Sensitive & Peeling. It doesn't work quite as well, but it's a small price to pay for the absence of unrelenting eczema, that wouldn't let up no matter how hard I scratched - and was starting to affect my appearance and quality of life in general.

If you're not allergic to Formaldehyde, try the Original formula.

If you have eczema, be careful - possibly switch to Sensitive & Peeling - it wasn't worth the stress on my skin and immune system to keep using the Original (and try eliminating dairy, caffeine, alcohol and other strong household detergents etc). continued >>

Since I have no intention to use this product like the pamflet says, take my review with causion. I apply one layer of this and keep it on as long as it looks neat. So I basically use this like nail polish. Any of the nail hardeners I've tried last as long as they're supposed to, so I don't even try anymore.

This one leaves a nice, shiny and moderately even finish on my nails. It's quite easy to apply lightly. My nails are growing quite fast but that might be more due to the fact that I massage cuticles many times a day than this one working. Peeling is possibly lessened a bit, but that's probably due to better moisture on nail. This is an average, very pricey product(at least in Finland). I bought it online for about ten bucks, here the prize is around 30€. Unbelievable!
The reason I wanted to try this was the fact that this hasn't got formaldehyde(?) in it, and I wanted to examine if I'm allergic to it or not. For now, this seems to work in the same way that one's with f-hyde do.

It peels within days, and halfway through the bottle it has become so thick it's stringy, but it does help my problematic nails that occassionally peels. I don't think I'd buy this again.

i am on my second day of opi s & p, so far so good-i've had my hands wet, applied hand cream, and no peeling of the treatment. my nails look alot better already. have tried nailtiques #2 and had problems with it peeling/flaking, so we shall see- will keep posting....

9/30/07....my nails have been growing out very nicely- last night i hit one of the longer ones on a wood beam in the basement, and normally it would have cracked or broken- this time it didn't! i agree about the getting stringy thing, which mine is starting to do; i may add a drop or 2 of nail polish remover and see if that helps. otherwise i like it, but may switch to the regualr envy when i'm done with this bottle. continued >>

I used the original Nail Envy, then decided I would like to try the one for sensitive peeling nails. I have to wash my hands a lot at work and nails were peeling terribly. The shop had to special order this for me. I tried it and as with the original you apply 2 coats, then one coat every other day. I couldn't even make it to the 3rd day for the third coat before it all peeled off. It was very disappointing. I took it back to the shop and they wouldn't take it back because it was a special order. I told the lady at the shop that it was awful and she said that she knew that. I asked why she didn't tell me and she said that she thought I knew what I was doing. So, I was stuck with this junk. Nope, I emailed OPI and it took a while but they sent me a bottle of original Nail Envy.
If you get a product you don't like, either contact the company or take it back to the store. A lot of people don't know that you can return cosmetics and lose a lot of money trying new things. Use the Original nail envy if you want nice strong nails. Use it as directed, not as a base or top coat. I have purchased from ebay but now my local wal-greens has it for 9.99. That's pretty good.

I bought this, hoping it would help my nails to grow past the nailbed without peeling and breaking off. It did help them to peel a bit less. Unfortunately, I paint my nails every few days with polish, and this makes a pretty bad base coat. My polish chipped, and my nails quickly turned extremely yellow. I'm not sure if the Nail Envy did this, or if it just allowed the polish to do it. It's okay, and does some of what it claims to, but I'm hoping to find something a bit better for my needs.

I liked this product until it glued the lid to the bottle and I could no longer use it. It did work to keep my nails from peeling as long as I wore it, but it chipped quite a bit, and the texture is SO thick and gluey. I'm going to look for something else.

This is intended as a product to use when your nails have got to how you want them after using nail envy, I have to say its not too bad a product but, I would sooner just stick with Nail Envy, which is a good product but, thinking of trying Essie's strengthener.

just pure crap!