Lash Filler 25.9 Step-By-Step Guide

Our Lash Filler range is an extremely popular treatment in the lash lift industry, but we’re always looking for ways to improve, which is why we are excited to introduce the updated Lash Filler 25.9 system! Research from a prominent University Institute in Italy confirms that this upgraded treatment not only increases the thickness of the lashes by up to 24% within 3 treatments, but it also increases the length by 9%, hence the new name… 25.9. To learn more about what’s new, you can check out this blog here. Now we’re going to go through the new system step by step to achieve optimal results with Lash Filler, ensuring your clients’ lashes look spectacularly lush while promoting lash health.

Lash Filler 25.9 products

Step 1: Preparation

The path to full, beautiful lashes starts with meticulous preparation. Ensure that both the lashes and skin are completely clean and devoid of any makeup, skincare residues, or oils. Our Foaming Lash shampoo should be used for deep cleansing, followed by a gentle but thorough rinse and a pat dry to create an ideal base for the treatment.

Step 2: Applying Eyepatches and Shields

It is essential to protect the lower lashes with eyepatches to avoid accidental product application. The next and very important step is selecting the right lash lift shields—they need to fit the lashes properly to achieve the desired lift without any unwanted bends. If you’re struggling with which lash lift shields to use, check out this deep dive into the different shields we offer.

Lash lift shields

Step 3: Lifting the Lashes

Once the shields are set, proceed with the lash lifting using Fixing Gel or Lamica Gel. This process must be done delicately but thoroughly, lifting each lash section by section to avoid the gel drying out too soon. Employ the Fillering Tool and the InLei® Helper Tool to accurately place and separate the lashes on the shield, ensuring each is perfectly positioned for an even lift. This is the position that the lashes will be set in, so make sure they are perfectly aligned!

Step 4: Form 1 Application

As in the original Lash Filler treatment, the transformation begins with the application of Form 1, which opens up the hair cuticles and breaks down disulfide bonds. This product should be applied carefully to the middle part of the lashes, avoiding the roots and tips. The application time varies between 6 and 12 minutes, depending on the lash condition. Once the time is up, remove the product using a dry cotton pad or a clean, dry brush.

Lash lift solution application

Step 5: Fix 2 Application

Immediately following the Form 1 removal, apply Fix 2 to reshape the disulfide bonds into their new elevated configuration while the cuticles are still open. This step also helps begin sealing the cuticles to maintain the new form. The duration for Fix 2 should be half of what you used for Form 1 plus one additional minute. Remove this with a dry cotton pad once the time has elapsed.

Step 6: Tinting

Although optional, tinting can greatly enhance the dramatic effect of the lift, particularly for those with lighter lashes. The lash tint should be blended with a cream developer in equal parts and left on the lashes for 6 to 12 minutes, depending on their thickness. Ensure to use a plastic InLei® mixing bowl to avoid any unwanted chemical reactions that metal containers could cause.

Step 7: Filler 3 Application

The final chemical application involves Filler 3, which deeply conditions the lashes whilst helping to remove any leftover tint and Fixing Gel and unsticking the lashes from the silicone shields.  This step ensures the lashes are fortified and silky post-treatment. Previously, Lash Filler 3 was left on the lashes and used to remove the lashes from the shield, however, this is where things have changed slightly. Lash Filler 3 is now left on for 1-2 minutes only.

Step 8: Mousse Magica

After the Lash Filler 3 has been on for 1-2 minutes, the lashes are washed with InLei® Magic Mousse. This specially formulated aerosol cleanser removes any residues from the treatment while ensuring that the lashes remain perfectly conditioned. This not only enhances the treatment effects but also reduces the risk of any allergic reactions by ensuring there is no product residue left on the lashes.

Mousse Magica

Step 9: Lash Molecular 4

Now, for the most exciting addition, the treatment is finished with the brand new Lash Molecular 4! This gel formula is a no-rinse product and is applied across the entirety of the lashes at the end of the lash lift treatment to reconstruct the hair. It contains hair-strengthening nutrients such as hair-specific hyaluronic acid, hydrolysed wheat protein, hydrolysed quinoa, and hydrolysed vegetable protein. The small-molecular formula means it can easily penetrate the hair shaft, locking in all of those ingredients, providing increased shine, colour retention, and pH rebalancing for weeks to come.

Step 10: Finishing Touches

To complete the treatment, remove the shields and delicately fluff and separate the lashes to enhance their appearance. Displaying before and after photos can vividly showcase the enhancement. Remember to clean, sanitise, and disinfect each shield thoroughly to prepare it for the next use.


Of course, lash lift aftercare is still more important than ever. Post-treatment, it’s advised that clients keep their lashes dry for the first 24-48 hours and avoid excess heat, such as saunas or sunbeds. Recommend a lash serum, like our Adiutrix Lash Serum and Fashion Lash Conditioner to help maintain the effect of the treatment for a longer period and promote the health and growth of the lashes. For a full lash lift aftercare guide, take a look at this blog.

See… it’s still the Lash Filler you know and love, just with a slight makeover! We have worked extremely hard to level up the Lash Filler line, and know that Lash Filler 25.9 will help you achieve better results than ever before! Explore the full range of Lash Filler products and start delivering transformative lash lift treatments with confidence.