I was very fortunate to not have any problems with my fingernails during or after chemotherapy. My toe-nails were not so lucky. Towards the end of my chemo treatments, both of my big toenails became very sore and darkened in color. My oncologist assured me this was normal and warned that the nails may begin to pull back and eventually fall off. After a couple of weeks, the soreness subsided. It was not until 2.5 months after my last treatment that the first nail fell off. Below is a picture of my toe the day that the nail fell off. It was not painful, because a new nail had already begun to grow under the dead nail.

The big toe-nail on the other foot fell off a few weeks later. The picture below shoes my toenails 5 months after my last chemo treatment. While some of the smaller nails were still discolored, only the big toenails on each foot fell off.

With summer approaching, I decided to try using fake toenails. I found the glue-on toenails found in the link below, which came with 4 sets of nails in a large variety of sizes.
https://www.amazon.com/gp/product/B009AEIBB2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I only applied the glue to my new toenails. I did not apply it to my skin or to the entire fake nail. The fake nails stayed on anywhere from 2 to 14 days. As my natural nails grew longer, the fake nails tended to stay on longer. The picture below shows the fake nails applied to my big toenails and all toenails painted. This picture was taken the same day as the above picture (5 months after my last chemo treatment).

I continued to wear these fake toenails for around 5 months, using two packages of the Kiss Products Full-Cover Toenails. At that point I felt that my natural nails were long enough to paint without the fake nails. The picture below shows my natural nails, around 9 months after my last chemo treatment.

