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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

  • Based on 2,311 reviews
Condition: New
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Availability: In Stock.
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Arrives Tuesday, Jun 2
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Features

  • YOUR SOLUTION FOR: brittle or weak nails
  • TESTED: Increases nail strength and durability while helping to repair brittle nails and reduce roughness
  • TECHNOLOGY: Silanediol salicylate promotes silicon, one of the predominant minerals in the nail, while pistacia lentiscus gum promotes keratin, an essential component to strong and healthy nails. Cationic hyaluronic acid, an enhanced version of one of the most well known moisturizers in the world, which promotes cuticle moisturization.
  • DEVELOPED IN: Spain

Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 1.61 x 1.14 x 5.67 inches; 0.63 ounces


Department ‏ : ‎ womens


Manufacturer ‏ : ‎ ISDIN


Best Sellers Rank: #11,699 in Beauty & Personal Care (See Top 100 in Beauty & Personal Care) #22 in Nail Strengtheners


#22 in Nail Strengtheners:


Customer Reviews: 4.0 4.0 out of 5 stars (2,376)


Liquid Volume: 2.5 Milliliters


Number of Items: 1


Unit Count: 1 Count


Size: 1 Count (Pack of 1)


Brand Name: ISDIN


Manufacturer: ISDIN


Manufacturer Part Number: 690017415


Item Form: Gel


Specialty: Strengthener


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Jun 2

This item is non-returnable:

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

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Top Amazon Reviews


  • Amazing results!
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! ... show more
Reviewed in the United States on June 4, 2024 by Letty Graff

  • Excellent product.
because it is such an expensive product and it did not work I thought about it a lot but I have been using it for 1 month. I do not use it daily at least 2 times a week but my nails grow and they are a little harder. I do not regret having bought it. good product and if
Reviewed in the United States on February 22, 2026 by Kari

  • Did not work for me!
I have been using this for 25 days. It claims visible results in 14...my nails are still peeling and breaking. It claims that it moistened cuticles...immediately after you put it on yes it does but they are all dried up within an hour. For the cost this product is not worth it...I will not buy again. ... show more
Reviewed in the United States on March 7, 2026 by Jodi Aviles

  • Strong nails
My nails used to split, break. I have been using Isdin Si-Nails for several years and my nails are much stronger, no longer break. I use every day, the reason it’s much better than other nail strengtheners, it dries quickly after spreading on cuticles and nails.
Reviewed in the United States on February 18, 2026 by Patricia

  • Fantastic product!! Worked wonders for me!
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. ... show more
Reviewed in the United States on August 13, 2025 by Suzannebsn68

  • Really truly works
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 ;) ... show more
Reviewed in the United States on April 11, 2025 by GdF

  • Works
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. ... show more
Reviewed in the United States on August 19, 2025 by Jehri Maguire

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