ISDIN Si-Nails - Fast Absorbing Nail Strengthening and Hardening Serum for Nail Durability in Thin Nails, made with Cationic Hyaluronic Acid 0.08 FL OZ

This stuff was literally an answer to prayer! HIGHLY RECOMMEND! I had been struggling with thin, peeling nails for over a year. I had back-to-back surgeries and my dermatologist told me my damaged nails were probably a result of the anesthesia. (I've never done regular manicures and very rarely polish or gel, so I couldn't blame that.) My nails were so thin they hurt and they would continually split and peel no matter how much I used nail strengthening treatments or polishes. I was at my wits end and tried ordering ISDIN as a last resort. I thought it was a little expensive at the time, but now I believe it was worth every penny! I keep an extra tube on hand now so I never run out. The product and brush are so easy to use. In the beginning I applied it twice a day but tried to keep using it at least once a day for two months. Now that my nails have improved I use it about every 1-2 days. The product is easy to apply and dries and disappears very quickly. I was worried it would be messy and sticky but it is not at all. Sometimes it takes one click per nail to get it going, but sometimes one click will treat a few fingers. A little goes a long way and you will get the feel of it. The product does take time to work. It was 2 months before I had a complete nail grow out without peeling. They are strong now but I am still careful to not use my nails as "tools" so that I don't break them. I still have a split on my thumbnail but I believe it will grow out as long as I am careful and keep applying the product every few days. I will say my nails are a little "ridged" and I don't know if that's just my nails or a result of the product, but it is a small price to pay for strong nails and I can just buff them down smooth. The photos you see are: 1. at the beginning of use, 2. after 6 weeks of using the product, and 3. at 2 1/2 months (they do grow longer but I like to keep them short) Don't hesitate! Buy this product!

I've been using it once a day for five minutes. I've only been following this routine for 4 days, but my nails are becoming shiny and strong. I apply it to my entire nail including the cuticle and let it sit five minutes. Rub it in, then spread all over my fingers and hands. It sells nice, but mild, must be the almond oil. Previously, my nails were chipping, splitting, dry and had severe ridges. They are now much smoother and strong and shiny. I love it! And i love my nails!

This product has made such a big difference in my nails. My doctor sent me to a dermatologist who told me there wasn’t anything they could do for me since prior treatments were not effective. My nails had major ridges, the nail had separated from a portion of the nail bed, they would break or tear easily, and were thin. I started using this product on May 9, 2025, and I used it as recommended faithfully, and within weeks I was noticing such great improvement in my nails. They are stronger, have less ridges, and the nail is no longer separated from the nail bed. I thought it was ridiculous that I had to pay the $50 copay to the dermatologist only for him to look at my nails and discuss the situation for like 5-10 minutes. But since he recommended I try this product, and it has been successful in repairing my nails, I suppose the $50 copay was worth it in the end. 😆 I highly recommend this product if you suffer from similar symptoms. I’m including two “before” pictures, and one “after” picture. Great product!! The only reason I did not give 5 stars is due to the price, which I feel is a tad high. I was lucky to find it on sale, so I snagged two pens at the sale price.

A fantastic fix! Expensive considering it comes with very little product

Life changing (at least for my nails LOL). I never leave reviews but this is too good not to share. Disclaimer: I'm a nail nut. A few years ago, at the age of 53, I decided I was very tired of brittle, flaky, dry, weak nails. I have always taken care of my nails, so the changes I was seeing were age related. I was eating healthy and exercising, was using nail polish but never gel, I moisturized etc. Nothing was helping. I used a special nail oil 6-8 times a day and no acetone and no nail polish for A YEAR and saw very little improvement. Then I discovered Dr Dana's Deep Hydrading Formula and saw an immediate improvement using their Deep Hydrating Formula...again I applied it on average 6 times a day so definitely was committed. My nails stayed short but stopped splitting and chipping...that was after about a month of use. They also have a hyaluronic serum but recommend using once a week. Then I discovered this product and went nuts with it. I bought three applicators, kept one by my desk, one in my bathroom and one in my car. I probably apply it 12 times a day LOL...certainly after any time I was my hands. It's easy. I apply a top 'coat' of the Dr Dana Formula after using the SI-NAILS. This is the magical combo. My nails are strong, flexible, and growing. This is the best they've looked in 20 years. So if you are unhinged like me and willing to go the distance, the combo of these two products changed my nails, they look 30 years younger ;)

I have waited four months to write this review because it just seemed too good to be true. But it is true. I am a senior citizen who suddenly found all my nails chipping, cracking, and splitting. I thought about posting a "before" picture, but they looked too awful. I used to try to hide my hands when in public. I tried nine months of biotin capsules, and no results. I found a recommendation from other users online of the ISDN product. When I started using it, I was completely skeptical. The product is clear, thin, and more like water than anything else. I could not see how this could work. It took six to eight weeks before I began to see genuine results - tiny 1/8" nails taking the place of nails that looked like they had been chewed off by rats. Now, five months on, I have 1/4" normal-looking nails that make me happy every day. I have to file them to keep from getting too long, but not in order to even out breakage. They don't seem to chip or break at all under normal use. I actually took the ISDIN box to show my doctor. She said they often have people ask for help with breaking nails, and they never have anything to suggest. She took down the info about this product. For me, a container lasts about two months or longer. I have noticed that the applicator doesn't always work the way the instructions say. Often I get enough product from one "click" to do a whole hand. Other times, the applicator needs to be primed several times. But I don't care as long as it works SO well. Reading over my review, it looks like someone paid me to write it! It's all true.

I have used this multiple times a day for a week. I do truly believe it is helping where my nails have separated from the nail bed due to use of acrylics and glue on nails. The cost of the product really has me unsure if I’ll order again. It’s taking several clicks now to dispense product. I do love the style and ease of use of the pen.

I’ve been using this off and on for about 2 months and have noticed a difference on my brittle, peeling nails. I’ve tried dozens of different products and nothing else has helped. I’ve put this on my bare nails 3-4 times a week at night (when I wasn’t wearing nail polish) and it has drastically reduced the peeling and cracking that has taken over my nails as I’ve gotten older. It is pretty expensive but I’m on the same tube 2 months later so it’s definitely worth a try!