Here are a few posts you may have missed:
Formaldehyde Nail Treatments
Are Formaldehyde Based Treatments right for you?
Protein Based Treatments
Obviously, this type of treatment combines the power of formaldehyde and protein. Each one has it's own mechanism for nail strengthening and instead of retyping what I wrote in previous posts I will just point you to the list above. In short, formaldehyde creates cross-linkages between the keratin in your nail plate making it harder, while the protein (often claims to do the same ... I don't buy it until I see scientific proof) offers reinforcement through it's filaments. As for determining weather this type of treatment is right for you ... again I would point you above. In short, thin, very soft, peeling nails may benefit from this type of treatment. However, if your nails are peeling because they are dry, moisturizer may help just the same and formaldehyde may make it worse.
As with the formaldehyde only based treatments, overuse of Formaldehyde + Protein treatments can cause the keratin in your nail to form too many cross-links and as a result the nail becomes very hard, looses its flexibility and becomes brittle. It's probably best to use this treatment intermittently to avoid brittle nails and possible worsening of your nail's condition (i.e. more chipping, peeling, etc.). As always, moisturizer should play an important role in nail maintenance.
Also, since formaldehyde is a skin irritant, overtime people can build up an allergy. Skin contact should be avoided.
Now on to examples:
Most treatments of this kind actually contain conditioners so they will have to wait till the next post, but the only one I could find that strictly fits in this category is ...
Does anyone want to share their experience? Perhaps your nails condition before and after treatment?
The complete series:
Categories of Hardeners and Formaldehyde
Are Formaldehyde Hardeners right for you?
Protein Based Hardeners
Formaldehyde + Protein Based Hardeners
Formaldehyde or Protein Based Hardeners + Moisturizers
Fluoride Based Nil Treatments Part I
Fluoride Based Nail Treatments Part II
Dimethyl Urea Base Hardeners
Nail Conditioners Post or Video Review of DermaNail