Lash Fill: Why and How Often Should It Be Done?

By Emily M.| Last updated on June 21, 2023
Lash Fill: Why and How Often Should It Be Done?
⏱️ 5 min read

Eyelash extensions are the most popular way of enhancing your lashes. Once you get them, it’s easy to get hooked – you love your new look and can’t imagine your life without them.

However, they are not really low-maintenance. The first thing you need to know about eyelash extensions is that they need to be maintained, primarily with a regular lash fill.

But the most common questions are how often should these infills be booked, when is it time for a new fill, and how to prolong the interval between the lash fills.

So, let’s discuss all these questions!

Why Is a Regular Lash Fill Necessary?

The first thing you should know is how long eyelash extensions last. Since they are attached to your natural lashes, the extensions will follow their growth cycle and fall off with them. The full cycle lasts 6-8 weeks, but that doesn’t mean your extensions will look good for so long.

When you get lash extensions, not all of your lashes are at the same stage of the cycle. Some of them are new, aka baby lashes, but some of them will fall off the very next day since they are at the end of the cycle. So, you can expect that approximately 40% of your natural lashes will fall off in 3 weeks – and the extensions will go with them.

A lash fill is required to add new extensions to the natural lashes that have grown in the meantime. If you skip the regular lash fill, you will probably need to get the full set again.

Why Is a Regular Lash Fill Necessary?Image source: Instagram @luxxaestheticsokc

How Often Should I Have a Lash Fill?

Most lash extension technicians advise you to get lash fills every 2-3 weeks. Sometimes, you can wait longer than that, even up to 4 weeks, depending on the retention as well as how you maintain your eyelash extensions and which skincare products you use (more on that below).

Most lash techs require you to have at least 40% of extensions remaining for the lash fill, otherwise, it will be considered a full set.

How Often Should I Have a Lash Fill?Image source: Instagram

How To Prolong the Time Between Lash Fills?

Proper maintenance will help you prolong the time between the two lash fill sessions. Here are the things that affect the lifespan of your eyelash extensions and tips on how to prolong the time between the two infills:

  • Try sleeping on your back, if you find it comfortable. The way you sleep will affect how many lashes you lose, so if your face is in the pillow, the extensions will not last very long.
  • Don’t rub the lashes and be gentle when you wash your face.
  • If your lashes are often exposed to water and heat, they will last shorter. Swimming, going to saunas, being in places with high humidity will shorten the lifespan of your lash extensions.
  • Oil-based skincare products will also shorten the lash extension’s lifespan because they will break the bond between the natural lash and the extension, so try to avoid them.
  • Wearing mascara is usually not advised when you have extensions, especially if you get volume, hybrid or wispy lashes. Classics are good to go, so if you truly wish to, you can give extension-safe mascaras a try.
  • Oily skin and hormones can also affect retention, but there’s not much you can do about that.
  • The most important lash extension maintenance tip is cleaning the extensions regularly and properly. If you don’t, the dust, oils, and sebum will build up and weaken the bond, thus making your eyelash extensions fall off prematurely. 

How To Prolong the Time Between Lash Fills?Image source: Instagram @blooming_beauty00

How Much Does a Lash Fill Cost?

The price of lash fill depends on many factors, such as how much time has passed since the previous application and how many extensions you have left. Also, salons have their own pricing policies and some of them even charge per lash added.

On average, lash fill costs 50% of the price of the full set, if you come within 2-3 weeks. The more time passes, the more extension will fall off and the price will be higher.

How Long Does Lash Fill Treatment Last?

While applying a new set lasts around 2.5 hours, lash infill usually lasts 1-1.5h, depending on how many new lash extensions need to be added.

Lash Fill Procedure

Here’s what lash fill treatment looks like:

  • The technician will assess your lash extensions to see how many have remained, to see if there’s enough for the infill, or you’ll need a full set.
  • The tech will isolate bottom lashes before they apply new extensions on the upper.
  • The lash tech will clean eyelash extensions that are still on your eyes, remove the lashes that are ready to fall out due to the natural growth cycle and remove any weak bonding lashes.
  • Then they prime the lashes and apply new extensions on the lashes that are naked.

Extra Tip

If you want to change the lash extensions style, you can tell your lash tech. For example, if you have classic extensions, you can add volumes for a wispy and more dramatic look.

Lash Fill Treatment ProcedureImage source: Instagram

When Is It Time for a New Set?

Filling in your lash extensions constantly is not really healthy for your natural lashes. Even if you clean them regularly, there will be some dirt and debris remaining and all the extensions should be removed to give your natural lashes time to breathe and recover.

In order to keep your lashes healthy, you shouldn’t have more than 2 refills between full sets. As lash techs explain, even though they clean the lashes when they do a refill, there is some adhesive remaining, onto which more is added for a lash fill.

Image source: Instagram @nova_esthetix

Lash Extensions Removal

If your extensions have grown out and you want to remove them by yourself, you can do that with the help of Vaseline. Vaseline lash extension removal is an effective method for dissolving the molecules in semi-permanent lash glue and getting rid of extensions.

All you need is a jar of Vaseline or other high-quality petroleum jelly, Q-tips, cotton rounds, and a spoolie or clean mascara wand. But, we have to note that you should be gentle when doing this as there is a risk of permanent lash damage due to pulling.

So, the best and safest thing to do is to leave lash extension removal to a professional lash tech. They know how to do that properly, without damaging your natural lashes and which products to use.

Learn all about eyelash extensions removal in this guide.


Regular lash fill is the only way to maintain a great look of your eyelash extension. Make sure you brush your lashes regularly and clean them, to avoid getting an infection and to prolong the time between two lash fill appointments.

If you want to learn more about eyelash extensions, check out this guide.

Cover image source: Freepik



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