I've been using this since Feb 2011, and I've never had better nails in my life!

Pros:
Dries SUPER fast!
Looks nice on it's own
Seems to last forever, I've hardly made a dent in the bottle after months!
Has made my nails long and healthy!!

Cons:
Expensive!! With tax I payed $20!

I am a forever fan of this! I use it 1-2 times a week, whenever I do a my nails. I just put a coat of the Envy on, and then put my nail color on and there you go! I don't use it as a top coat, or alone, I just put my favorite nail polish over it, and it's amazing! My nails have NEVER been this long or strong or looked so nice before! I will DEFINATLY buy this again!

At first, I absolutely loved this stuff and raved about it, but after a month of use, I noticed that my nails were yellowy-orange and began wondering if I had some sort of medical disorder or nutrition deficiancy. I happened to Google yellow nails to see what I could find when I came across the link between using Nail Envy and yellow nails. It makes perfect sense seeing as I have been using it and am quite health conscious, taking vitamins regularly.
I have no idea why this yellowing happens to some of us but not all of us. My nails look horrible!

I really really hate the ORIGINAL one. Claims to help strengthen your nail but that's full of c**p! after using it as a base coat my nail is actually weaker and drier. waste of $$!!
I also have another one call MAINTENANCE, this one is acceptable compares to the ORIGINAL. but I still wouldn't buy it again because I don't believe the company would change the formula THAT MUCH.
so i went ahead and threw away the ORIGINAL and I will say BYE BYE to OPI Nail Envy once I'm done with the MAINTENANCE.

This is by far the worst nail treatment I have ever used on my nails. I've always had dry and brittle nails and because of this I have tried a lot of brands and treatments, and most of them has had some kind of effect, even if it's been a really tiny one, but Nail Envy has no effect watsoever on my nails. I really wanted this towork so I gave it 6 months before I gave up. Not only did my nails still break and split, it didn't do what I expect the most basic base coat to do: to protect my nails from staining.
Since then I've found that Trind Nail Repair works best for me, with Sally Hansen Nailgrowth Miracle on second place, So if your nails tend to behave like mine do and Nail Envy doesn't do the job, maybe you should try one of these instead.

I'm going to be the rogue reviewer here and say that this stuff dried the crap out of my nails. Formaldehyde is listed twice as ingredients in this formulation and that alone should have served as a warning to me. When I was at my wits end I added my own drops of Almond Oil to this product in order to make it somewhat moisturizing. What's the point of strong nails if they are left bereft of all moisture?

And I won't be trying their other formulas. I think I'll continue the search for a formaldehyde free product that contains moisturizing ingredients that promote elasticity as well as strength.

I am loving this product! I got a baby sample in a kit that was on clearance from Ulta and after using for about 2 weeks, I can say I honestly have noticed a significant difference in my nails. For the first time, after many different nail growth products, my nails are growing in stronger and evenly and not breaking or bending as soon as they pass my finger tip a little. Normally, I can't keep my nails long for more than a day without them peeling, breaking, or something. I will continue using this until my sample runs out and then I'll bite the 16 dollars and purchase myself a new bottle. My only complaint is that it takes a bit to dry. I wish it dried instantaneously but I am willing to overlook it if these results keep up. I am one happy customer!

I'm kinda lazy and I could not live with bare nails so I have probably not used it completely as it is intended. But what I do is that I always use it under my nail polish, and for me it is definetly making my nails better than without it, its no miracle cure but I never though it was either so I'm pretty happy with the product.

I was recomended this product after I had gel nails removed by my manicurist. I almost didn't purchase this due to the price (I believe I paid over $20CAD) but figured I'd give it a shot. It was totally worth it, and I now have been using it for almost a year. My nails can actually grow and are very strong. Ocassionally I apply a nail color on top and then another layer of the hardner on top, it still works great.

The only con I find is the it can chip after about 3 days but since it is clear it is very easy to reaply quickly and it does dry rather quickly.

Over all I would recomend this if you have brittle nails, it works much better then tipical drug store brands.

(I'll be reviewing this as its intended purpose as a nail treatment) So I have dry nails that split easily. My nails do a weird internal split where the layers are separated, but rarely come apart. It's more as a result of impact to the nail edge and leaves a white mark and with more hits, the split can work its way down the nail. Working in retail and dealing with metal hangers/clothes, my nails receive a lot of roughing. I don't have the luxury to wear gloves while doing chores/work, so for the price of $16, I expected good results. I think my mistake was asking for a miracle. I'm 100% positive that if I took 1-2 weeks off work and babied my nails with Nail Envy, I'd have great looking nails. But as it is, I can't and my nails have continuously split, even following directions of applying 2 coats the first day and 1 coat every other day. What I can say though is that I did successfully repair a split toenail using nail envy since my toes don't see a lot of action. But for the hands, Nail Evny does the best as it can and I can only say it's better than the Sally Hansen treatment's I've done. So 3.5 stars for Nail Envy and still on the fence if I'd buy more.

Nail Envy protects bare nails like a shield. Its transparent and enhances their natural beauty. It gives a very shiny clean look.