Yes — with two conditions. A lash serum can be used with eyelash extensions if it is oil-free and applied to the skin along the upper lash line rather than onto the extensions themselves. After a lash lift, wait until the lift has fully set — most lash artists say 24 to 48 hours — then apply once nightly.
The reasoning behind those rules matters, because it covers what a one-line answer doesn't: the night before a fill, or the morning your retention drops.
Why oil — not serum — is the thing your lash artist worries about
Eyelash extensions are bonded to your natural lashes with a cyanoacrylate adhesive, the same chemical family as superglue. Oil breaks it down. Lash education brand Lash Affair puts it bluntly: "Oil dissolves cyanoacrylate adhesive, this is chemistry, not opinion."
That single fact sits behind every rule handed to you at the end of an appointment: oil-free cleanser, no cleansing balm, no rich eye cream, no castor oil. Serums are not the problem — oily products near the bond are, and plenty of lash serums are oil-based.
So scan the label for mineral oil, castor oil (Ricinus communis), coconut, jojoba, argan and sweet almond oil. An oil in the first few lines of an ingredient list is a meaningful amount.
One exception worth knowing. PEG-40 Hydrogenated Castor Oil reads like castor oil on a label, but it is not one. It is an ethoxylated derivative used as a water-soluble solubiliser — a surfactant that helps actives disperse in a water base — and it is routinely used to build oil-free formulas. It does not sit on the lash as a lipid film the way free castor oil does. If you see it on an otherwise oil-free ingredient list, that is not a red flag; a free oil high in the list is.
Using a lash serum with eyelash extensions
Wait until the adhesive has fully set
Cyanoacrylate keeps polymerising after your artist finishes, which is why the standard instruction after a set or fill is to keep the area dry and product-free for 24 to 48 hours. Start the serum after that window, not on the drive home — and if your artist quotes a different number, follow theirs.
Apply at the lash line, not on the extension
This is the part people get wrong. The Lash Professional gives the clearest instruction: "Apply a thin line of serum along the base of your upper lashes, just like you would with liquid eyeliner. Avoid getting the serum directly on your extensions." The same page adds: "Allow the serum to fully dry before applying makeup or going to bed." A wet lash line pressed into a pillow is how product reaches the bond.
One thin pass, on a clean lash line
Excess serum has nowhere to go but into the bond, into your eye, or onto the pillowcase. Cleanse first with an oil-free lash foam, pat dry, then apply — Lash Affair reports that clients who cleanse daily "consistently retain their lashes one to two weeks longer than clients who do not".
Using a lash serum after a lash lift
How long do you actually have to wait?
A lash lift chemically softens the keratin in your natural lashes so they can be reshaped over a silicone shield, then re-sets them in that curl. Nothing is glued on, so the first day or two is about letting the new shape settle, not protecting an adhesive.
The most-repeated rule online is not what the manufacturer actually says. Elleebana — the Gold Coast company whose One Shot system is used in salons across Australia — states that "contact with water in the first 24 to 48 hours after treatment will not affect the end result." What it asks clients to avoid is heat and steam — hot showers, saunas — plus rich eye creams, face oils and conventional makeup removers, and it suggests a lightweight lash serum over castor oil.
So: 24 hours is the common instruction, 48 hours the cautious version — and your artist's aftercare card beats anything online.
Oils stay off the list afterwards too
Melbourne salon Posh Deluxe advises avoiding oil-based skincare around the eyes for the life of a lift, because heavy oils weigh a curl down and shorten how long it holds its shape.
Extensions, lash lift or bare lashes: what changes
| Eyelash extensions | Lash lift (and tint) | Bare natural lashes | |
|---|---|---|---|
| When to start | Once the adhesive has set — commonly 24–48 hours | Once the lift has set — commonly 24–48 hours | Straight away |
| Where it goes | Skin at the lash line, never on the extension | Skin at the lash line | Skin at the lash line |
| Oil-free formula? | Non-negotiable | Yes, to keep the curl holding | Cleaner under makeup |
| If you ignore this | Oil reaches the bond, retention drops | The curl relaxes early | Product migrating into the eye |
| Tell your artist? | Yes — bring the ingredient list to your fill | Yes — before the appointment | Optional |
Why prostaglandin-free matters more when you wear extensions
Some lash serums are built on prostaglandin analogues such as isopropyl cloprostenate, in the same chemical class as prescription bimatoprost. In Australia the Therapeutic Goods Administration draws the line by ingredients and claims: a cosmetic changes appearance, while anything that influences, inhibits or modifies a physiological process is a therapeutic good and must be on the ARTG before it is supplied or advertised.
For extension wearers the point is practical. The American Academy of Ophthalmology already lists allergic reaction to the glue, eyelid and corneal irritation and infection among the risks of extensions. A second irritant on an eyelid that is already reacting makes it far harder to identify the culprit.
LashOriginals Eyelash Serum is a 5 mL prostaglandin-free conditioning serum (A$49.90) built on peptides, biotin and panthenol. It is oil-free and water-based, so it does not contain the oils that break down cyanoacrylate adhesive, and it is ophthalmologist-tested — no isopropyl cloprostenate, no bimatoprost analogues. The full ingredient list sits on our safety and usage page: take it to your lash artist and check it against the oil list above. Same for the Eyebrow Serum and the Lash & Brow Serum Duo.
How long before you notice anything?
Lashes run on their own timetable. In a study of 29 women published in the British Journal of Dermatology, four participants were followed weekly for nine months; the researchers calculated the eyelash anagen phase at 34 ± 9 days and the complete eyelash cycle at 90 ± 5 days (Thibaut et al., 2010).
A conditioning routine is therefore measured in cycles, not days, which is why serums are used nightly over months rather than in a burst before an event. Under extensions you cannot see your own lashes until the set is off, so judge the difference at a removal.
A label checklist before you buy
- Oil-free? Scan for mineral, castor, coconut, jojoba, argan and sweet almond oil.
- Prostaglandin-free? Look for isopropyl cloprostenate or any "…prost" ingredient name.
- Fine-tip applicator, full ingredient list published, and patch-tested on the inner forearm before first use.
Frequently asked questions
Can I use a lash serum with eyelash extensions?
Yes, provided it is oil-free and applied to the skin along the upper lash line rather than onto the extensions. Wait until the adhesive has set after a set or fill — commonly 24 to 48 hours — and let the serum dry fully before bed.
Will a lash serum make my eyelash extensions fall out?
An oil-free serum kept off the extensions should not affect retention. Oil is what dissolves cyanoacrylate adhesive, so an oil-based serum, cleansing balm or rich eye cream is the real risk. If retention drops after you start a new product, pause it and check the ingredient list for oils.
How long after a lash lift can I use a lash serum?
Most salons ask you to wait 24 to 48 hours while the lift settles. Elleebana, the Australian lash lift company, says water in that window will not affect the end result, but asks clients to avoid heat, steam, face oils and rich eye creams. Follow your own artist's aftercare card.
Can I put lash serum directly on my extensions?
No. The serum is for the skin at the base of your natural lashes, where it conditions the lash as it emerges. Coating the extension achieves nothing and pushes product towards the adhesive bond. One thin pass along the lash line is the whole technique.
Should I stop using lash serum before a lash appointment?
Ask your artist, and tell them what you use either way. Some prefer a clean, product-free lash line on the day, so the adhesive or lift solution has nothing to work against.
Is castor oil bad for lash extensions?
For extension wearers, yes — castor oil is an oil, and oil breaks down cyanoacrylate adhesive. Elleebana also advises lift clients to choose a lightweight lash serum over castor oil, which sits heavily on the lash. A serum listing Ricinus communis high in its ingredients is not extension-safe.
Can I use a brow serum after brow lamination?
The same logic applies: lamination reshapes brow hair chemically, so let it set before adding anything and keep oils away afterwards. Allow 24 to 48 hours, apply an oil-free serum to the skin along the brow, and confirm the timing with your technician.
Will a lash serum do anything if I never take my extensions off?
A conditioning serum works on the natural lash at the lash line, not on the extension, so it can be used continuously between fills. You will not see the difference clearly while extensions are on, because your own lashes are hidden underneath. Judge the appearance at a removal.
Browse: all lash serums and lash care, including the Pro Lash Curler.
Related reading
- How to Apply a Lash Serum (and the Mistakes That Waste a Tube)
- Brow serums after lamination or tinting
- Best Eyelash Serum in Australia (2026)
- Do Lash Serums Actually Work? What the Science Says (2026)
- Prostaglandin-Free Lash Serums Explained: What the Ingredient List Actually Tells You
Sources
- American Academy of Ophthalmology — Eyelash Extension Facts and Safety
- Elleebana — Lash Lift Aftercare: The Elleebana Way
- Lash Affair — Lash Extension Aftercare
- The Lash Professional — Lash Serum With Eyelash Extensions
- Posh Deluxe — Lash Lift Aftercare Guide
- Thibaut S, et al. Human eyelash characterization. Br J Dermatol 2010;162(2):304–310.
- TGA — Cosmetic or therapeutic good?
General information about cosmetic products and salon aftercare, not medical advice. LashOriginals serums are cosmetics that condition lashes and brows and support the appearance of longer-looking, fuller-looking lashes. If you are pregnant, breastfeeding or experience irritation, stop use and speak to your doctor or optometrist.