Nutra Nail

I've used this strengthener as a base coat. It claims to strengthen nails and bond nail layers for extra durability. The brush is wide and easy to use. Nutra Nail Strengthener makes my nails feel harder, but it doesn't help to prevent my nails from splitting at the sides. However, when I remove my polish my nails don't look dry as they do with many other base coats. It also can be used without nail color.
It's free of formaldehyde, toluene, and DBP.

This is a really great product. At first I didn't think it was doing much more than hair conditioner (yes, if you're ever out of remover, hair conditioner is a pretty effective cuticle softener), but then I read a review about using a nail brush to scrub it off before actually pushing back the cuticles, so I tried it that way. Man, did my cuticles look fantastic! I barely feel the need to push them back now, the nail brush does most of the work.

I took off one lippy because it's a bit difficult to control how much product comes out, which ends up being wasteful. Also, the "built-in" cuticle pusher is pretty clunky and useless, you're better off using an orange stick.

Yes yes yes!!! This product is incredible! I love that there's no waiting for it to dry, it doesn't have any of the formaldehyde or drying alcohols that other growth treatments have. My skin and nails are terribly dry, and my nails are overwhelmingly slow-growing, thin and weak, tending to tear, rip, and snap. One week of using this, and all that changed. You have to be a bit religious about using it. For me, once upon waking and once upon going to bed worked wonders.
Pros: 1) It works! By gum, it actually works! 2) it's very easy to use. 3) for the price, it trumps every other product in its price range.
Cons: 1) the smell. To me, it smelled almost vaguely fishy. Ick. But the smell is not pervasive or strong, and you actually have to put your nose near your fingers and sniff to detect it (I don't make a habit of this, lol but there you have it). 2) for me, the portion of my nails that had grown before I started using it did chip and tear away. Though it could appear that the growth gel was he culprit, I really think that it was just old, thin nail tissue, and was weak like my nails have always been. Once it's grown out, there's not much any product can do to maintain it. It's dead skin at that point, and expecting there to be a way to strengthen it after the fact is fruitless. Especially since the new, fortified nail that grew in its place was so much stronger, and the nail replaced its lost length pretty quickly. Don't get discouraged by any breakage soon after using this product; it was likely breakage that was destined to occur anyway.

Endgame: I love this product and will not be wasting my money on anything else in the future.

This product makes my nails hard and protects them from breaking. I think the gel formula is responsible, because this strengthener is a little thicker than the many nail strengtheners I've tried. Instructions say to use as a base and top coat, which I did.

Unfortunately, this strengthener causes my hands to ache slightly for several hours after I've applied it, so I must have a sensitivity to one or more ingredients. In any event, I just don't like the feel of a thick coat on my nails.

This gel strengthener has acrylic polymer, protein, and calcium. According to the labeling, "This highly effective formula creates a powerful coating that instantly strengthens and hardens natural nails."

I used this strengthener as a second base coat, over Dior Base Coat Abricot, to add strength to my thin and weak nails.

If I apply this nail strengthener directly to my nails my hands ache slightly for several hours. I can, however, use Sally Hansen Triple Strong if I want to use a gel strengthener directly on my nails. In any event, I don't like a thick coating on my nails.

Note 2/18/16: This product seems to have been discontinued, although Nutra Nail makes a product called Triple Power Gel Strengthener that seems to be identical.

Nutra Nail products are free of formaldehyde, toluene and DBP.