I had some detachment (onycholysis) on both thumbs of my hands. I did the following (and saw improvement after 90 days of use):
1. I cut the nails to the limit of the detachment (as close as I could).
2. I applied the polish once or twice a day on the two nails.
3. Before it dried, I added 1 to 2 drops of 100% tea tree oil.
4. I continued to cut the nails as close to the limit of the detachment as possible and kept them clean.
The nails gradually grew attached to the skin, and the whiteness underneath them disappeared. As long as I didn't apply the tea tree oil, it didn't work particularly well, but when I added it and kept the nails really short at the limit of the onycholysis, then the improvement was immediate.

Don't bother at all, minimal product with an expensive price and at least if it did something I could say the money was worth it, but it is completely useless and I'm talking about a nail without any particular damage, I just thought to try this one to prevent potential damage and in the end after 5 boxes (almost 3 months) I saw no difference whatsoever.

I have been using it for 7 months. I apply it twice daily without fail, I file it every 5 days, and clean it with acetone every 2 days. Almost no difference. I was swayed by the reviews. I used 9 bottles of ONYPSO. Each bottle has very little quantity compared to the money. For me, 7 months went to waste. And approximately 150 euros. Thank you.

We were recommended this by a podiatrist for nails that were damaged after chemotherapy treatments. With frequent use, we saw improvement.

Amazing for nail thickening. My one nail is already much better and approaching normal after almost 25 years of thickening and with only two months of daily use of the product