When do I need a new full set of lashes?

When fewer than about 40 to 50% of the extensions remain, after more than 3 to 4 weeks without a fill, or every 2 to 4 months as a reset.

How do I make lash extensions last longer?

Keep them dry for the first 24 hours, clean them daily with an oil-free cleanser, avoid oil-based products and mascara, and do not rub or sleep on them.

Lash extension refill schedule

Q: How often should I get lash fills?

Every 2 to 3 weeks. After 3 to 4 weeks most people have lost more than half of the set and need a full set instead.

How often to book fills, why the lash growth cycle decides it, and what makes extensions last longer between appointments.

Most people need a lash fill every 2 to 3 weeks. Extensions do not fall out on their own; they shed with your natural lashes, which are replaced on a 6 to 10 week cycle. After about 3 to 4 weeks you have usually lost more than half, and most studios then recommend a full set rather than a fill.

The typical lash extension schedule

Appointment	When	What happens
Full set	Day 0	1.5 to 3 hours. An extension is bonded to each suitable natural lash.
First fill	Week 2 to 3	45 to 90 minutes. Outgrown extensions are removed and new ones added to the lashes that have grown in.
Ongoing fills	Every 2 to 3 weeks	Same again. Many studios price by how many lashes are left (for example a 2-week fill versus a 3-week fill).
Full set again	Every 2 to 4 months, or when less than about 40% remain	Everything is removed and reapplied so the set looks even and the adhesive build-up is cleared.

Why 2 to 3 weeks: the lash growth cycle

Every natural lash grows, rests and falls out on its own schedule, roughly every 6 to 10 weeks. On any given day a few lashes are about to shed, and an extension glued to one of them goes with it. On average people lose 3 to 5 natural lashes a day, which adds up to 20 to 30% of a set in two weeks and around half in three weeks.

That is why extensions look best with regular fills rather than one long gap: a fill keeps the set topped up as the cycle turns over, and the lash artist can also move extensions that have grown too far from the lash line.

When you need a new full set instead of a fill

Fewer than about 40 to 50% of extensions left. Below that it takes as long to fill as to start fresh, and most studios charge for a full set.
More than 3 to 4 weeks since the last appointment, even if retention was good: the remaining extensions have grown out and twisted.
Visible adhesive build-up or clumps that cannot be removed in a fill.
Changing the style, for example from classic to volume, or a different curl or length.
Every 2 to 4 months as a reset, so your natural lashes and the set stay in good shape. Some people also take a short break with no extensions.

Aftercare that improves retention

Retention is how many extensions survive between fills. Good aftercare can easily be the difference between a 2-week and a 3-week fill.

Keep them dry for the first 24 hours (some adhesives need less; follow your lash artist). No steam, sauna or sweaty workouts in that time.
Clean them daily with a lash shampoo or oil-free foaming cleanser and a soft brush. Oil, makeup and skin debris weaken the adhesive bond and can irritate the lash line.
Avoid oil-based products around the eyes: oil cleansers, heavy creams, waterproof mascara and oil-based makeup removers.
No picking, rubbing or sleeping face-down. A silk pillowcase helps; so does sleeping on your back.
Brush them gently with a clean spoolie each morning.
Skip mascara altogether, or use only a water-based one on the tips if you must.

Keeping track of your fills

Note the date, the lash artist, the style (classic, hybrid, volume), the curl and length, and roughly how many lashes were left at each fill. Over a few months you will see your own true interval: some people hold a 3-week fill easily, others are better at 2 weeks. Booking the next fill before you leave the studio keeps your preferred slot and stops the set from drifting into full-set territory.

Frequently asked questions

How long do lash extensions last?

A full set looks full for about 2 to 3 weeks and is usually mostly shed by week 4 to 6, following your natural lash cycle.

Can I go 4 weeks between lash fills?

You can, but by 4 weeks most people have lost more than half of the set and the studio may charge for a full set.

Do lash extensions damage natural lashes?

Correctly applied extensions, matched to the strength of your natural lashes and without picking or pulling, should not. Problems usually come from extensions that are too heavy, from pulling, or from skipped cleaning.

Glamdu remembers it for you

Log every full set and fill with style, curl and lash artist. Glamdu reminds you 2 to 3 weeks later, before the set thins out.

General information, not medical advice. How long a treatment lasts varies from person to person; always follow your injector, dermatologist or practitioner. Last updated October 14, 2026.