Lash Growth Serums: Do They Actually Work? A Perth Lash Artist’s Honest Guide to Ingredients, Safety, and Whether They Belong in Your Routine
Walk down any Priceline or Mecca aisle in Perth and you’ll see them stacked on the shelf. RevitaLash. GrandeLASH. Rodan + Fields. NEULASH. Vegamour. Even lower-shelf drugstore versions promising to “double your lash length in 8 weeks.”
At Posh Deluxe, we get asked about lash growth serums almost every single day. Do they work? Are they safe with extensions? Are the natural ones just glorified castor oil? Is Latisse worth the prescription? Why do some people rave about them while others say they turned their eyelids brown or caused their eyes to change colour?
Here’s the honest truth: lash growth serums can work — beautifully in some cases — but the category is genuinely confusing, occasionally unsafe, and often oversold. Some are excellent. Some are gimmicks. And a few are actively dangerous when used the wrong way or in the wrong combination.
This is our comprehensive Perth lash artist’s guide to lash growth serums — what actually works, what doesn’t, what to avoid, whether you can use them with extensions, and how to think about growing your natural lashes without buying every product on the shelf.
First: Do Any Lash Serums Actually Work?
Yes — but with major caveats.
There are essentially three categories of lash growth product on the market, and they work in completely different ways:
1. Prescription prostaglandin analogues (like Latisse / Careprost / Lumigan)
Prescription prostaglandin analogues such as bimatoprost have clinical evidence supporting their ability to increase lash length, thickness and darkness. Bimatoprost was originally used as a glaucoma treatment before its effects on eyelashes were recognised. Prescription products containing bimatoprost should only be used under the guidance of an appropriate healthcare professional.
Efficacy: Genuine. Most users see meaningful growth within 8–12 weeks.
Safety concerns: Real. Potential side effects associated with bimatoprost can include eyelid skin darkening, eye irritation, changes around the eye area and increased iris pigmentation, which may be permanent. Because bimatoprost can also affect intraocular pressure, anyone with an eye condition or using eye medication should discuss its use with their doctor or eye-care professional.
2. Over-the-counter serums with prostaglandin-like ingredients
RevitaLash, GrandeLASH, LiLash, Rodan + Fields Lash Boost — these use synthetic prostaglandin analogues (isopropyl cloprostenate, dechloro dihydroxy difluoro ethylcloprostenolamide, and similar mouthful ingredients) that mimic bimatoprost’s effect but are technically classed as cosmetic ingredients rather than prescription.
Efficacy: Moderate to good. Most users see visible improvement in 6–12 weeks, though results are usually less dramatic than prescription Latisse.
Safety concerns: Prostaglandin-like ingredients have attracted attention because of reported side effects around the eye area, including irritation, redness, skin pigmentation changes and changes in the appearance of the surrounding eye area. The exact risk varies depending on the ingredient, formulation and individual user, so it’s worth researching the specific product before committing to long-term use.
3. “Natural” conditioning serums
Vegamour, castor oil, biotin serums, peptide-only serums — no prostaglandin ingredients. These condition, hydrate, and strengthen existing lashes without stimulating regrowth.
Efficacy: Limited actual “growth” impact. What they do achieve is healthier lashes that are less prone to breakage — which can look like growth over time because your existing lashes reach their full length rather than snapping at 60–70%.
Safety concerns: Minimal. Most are safe with extensions if oil-free. Castor oil specifically should never be used with lash extensions — it will dissolve your adhesive.
The Ingredients to Actually Look For
If you’re standing in front of a lash serum shelf trying to decode the labels, here’s what each key ingredient actually does.
Prostaglandin analogues (bimatoprost, isopropyl cloprostenate, isopropanol phenyl-hydroxy-pentene dihydroxycyclopentyl-heptenate) These are the actual “growth” ingredients. Look at the ingredient list. If you see anything ending in -prost or containing “cloprostenate” or “hydroxycyclopentyl”, that’s the active driver of results. Understand what you’re signing up for.
Peptides (myristoyl pentapeptide-17, myristoyl hexapeptide-16) Support keratin production in your lashes. Improve strength and thickness of existing lashes rather than growing new ones. Safe with extensions and generally gentle.
Biotin, panthenol, hyaluronic acid Conditioning ingredients commonly used to help lashes look healthier, shinier and less brittle. They’re generally well tolerated, but don’t expect the dramatic growth associated with prostaglandin-based products.
Castor oil isn’t something we recommend with lash extensions, as oily products around the lash line can interfere with retention and make it harder to keep extensions properly cleansed.
Amino acids (arginine, glutamine, lysine) Support hair structure. Support conditioning. No dramatic growth impact but no risk either.
Vitamin E, vitamin B5, vitamin B7 Moisturising, conditioning, protective. Generally safe. Never a growth driver.
The Posh Deluxe Lash & Brow Serum: Our Pick for Extension Wearers and Sensitive Eyes
If you’ve read this far, you’ll know exactly why we built our own serum around a peptide-and-herbal formula rather than a prostaglandin one — and why that matters most for exactly the two groups who ask us about serums the most: extension wearers and clients with sensitive eyes.
The Posh Deluxe Lash & Brow Serum is made in Germany and formulated around myristoyl pentapeptide-17 — the same peptide complex discussed above for supporting keratin production — combined with eyebright and sea chamomile extracts. It’s completely oil-free, making it suitable for use as part of an extension-friendly lash-care routine, and contains no prostaglandin analogues. This makes it a very different type of formula from the prostaglandin-based growth serums discussed above.
Why we recommend it over a generic drugstore option:
- Genuinely lash-extension safe. Oil-free formulas are the baseline requirement, but a lot of “extension-friendly” serums on crowded drugstore shelves cut corners here. This one is built for extension wearers from the ground up.
- Gentle enough for sensitive eyes. The formula doesn’t contain prostaglandin analogues, making it an option for clients who prefer to avoid this category of ingredients.
- Made in Germany, with quality control standards that go beyond what a lot of imported budget serums offer.
- Works on brows too, so it doubles as one product for both areas rather than needing separate lash and brow formulas.
The brand’s own testing shows up to a 72% increase in length and density over 42 days of daily use — worth noting that’s the manufacturer’s stated result rather than an independent clinical trial, so treat it the way you’d treat any brand’s efficacy claim and give it the full 8–12 week window we recommend below before judging results for yourself.
How to use it: Apply a thin layer to the root of clean, dry lashes or brows once daily. Once you’re happy with results (usually around the 6-week mark), step down to every 2–3 days for maintenance.
This is the serum our own team uses and recommends in-salon, and it’s available to shop directly: Shop the Lash & Brow Serum →
The Serums You’ll See in Perth (and What They Actually Are)
Not naming other brands for legal reasons, but here’s how to categorise the products you’ll find on shelves and online in Perth.
Prescription Latisse / Careprost: The gold standard for actual growth. Requires GP prescription. Serious side effect profile. Best discussed with your doctor.
Premium OTC growth serums ($120–$300 range): Contain synthetic prostaglandin analogues. Real efficacy. Real side effects. Read the ingredient list before buying. Consider whether you want prostaglandin exposure long-term.
Mid-tier peptide/herbal conditioners ($40–$80 range): Usually peptide + conditioning ingredients only, like our own Lash & Brow Serum. Modest, cumulative results with essentially no risk profile. Our recommended starting point for most clients, and the only category we’d suggest without hesitation for extension wearers.
Drugstore lash serums ($15–$40 range): Often mostly castor oil, biotin, and marketing. Minimal actual impact. Fine if you don’t have extensions.
“Lash growth” mascaras: Rarely deliver on the promise. If a mascara claims to grow lashes, it usually just adds fibres or contains basic peptides that wash off nightly.
Can You Use Lash Serums with Extensions?
The most common question we get. Honest answer: sometimes.
Safe with extensions:
- Oil-free peptide-based conditioning serums (applied only to the base of the lash line, avoiding the extensions themselves) — this is exactly the category our Lash & Brow Serum was formulated for
- Salon-supplied lash foam with keratin conditioning
- Very light application of a water-based hydrating serum
Not safe with extensions:
- Any castor oil serum — dissolves adhesive
- Prostaglandin-based growth serums — depending on their formulation and how they’re applied, some lash artists find they can make extension retention and lash-line maintenance more challenging
- Anything with silicones, mineral oil, or heavy conditioning oils
- Lash growth mascaras applied over extensions
Our recommendation for extension wearers: Focus on protecting your natural lashes underneath, not stimulating regrowth via prostaglandin products. Use the salon’s take-home lash foam, brush daily with a clean spoolie, and avoid any product that could weaken your adhesive. An oil-free peptide serum like ours can be worked into your daily routine safely throughout your extension cycle. If you want to use a prostaglandin-based growth serum specifically, take a break from extensions for 6–8 weeks, use the serum during that break, then return to extensions with healthier natural lashes to work with.
The Prostaglandin Question: What You Should Know
Let’s talk directly about the ingredient category most Perth women are quietly worried about.
Prostaglandin analogues — the class of ingredients that make growth serums actually work at the more dramatic end of the results scale — have real, documented side effects. This isn’t scaremongering; it’s ingredient chemistry.
The most common side effects:
- Eyelid darkening — a brown/grey pigmentation around the lash line that can develop over months of use. Sometimes reverses when you stop the product; sometimes doesn’t.
- Iris colour changes — permanent darkening of light-coloured eyes (blue and green eyes are at highest risk). Extremely rare with topical use, but documented.
- Periorbital fat loss — a “sunken” or hollowed appearance around the eye area from fat atrophy over long-term use. Usually reversible when discontinued, but takes time.
- Changes in intraocular pressure — prostaglandin analogues such as bimatoprost can affect eye pressure. Anyone being treated for an eye condition or using eye-pressure medication should discuss lash-growth products containing these ingredients with their doctor or eye-care professional.
- Redness and irritation — common in the first few weeks. Usually settles. If it doesn’t, discontinue.
Who should speak to a healthcare professional before considering prostaglandin-based lash products:
- Anyone with an existing eye condition or using eye medication
- Anyone who has recently had eye surgery
- Anyone who is pregnant or breastfeeding
- Anyone who has previously experienced significant irritation or reactions around the eyes
- Anyone concerned about potential pigmentation or changes around the eye area
What Actually Grows Your Lashes Naturally (No Serum Required)
Before you spend $120+ on any serum, here’s what genuinely helps your natural lashes grow to their full potential.
Nutrition: Your overall nutritional health can affect your hair and lashes. If you’ve noticed significant or unexplained thinning of your natural lashes, speak with your GP, who can determine whether further investigation is appropriate.
Overall wellbeing: Sleep, nutrition and general health can all influence the condition of your hair and lashes. If you’ve noticed a sudden or unexplained change in your natural lashes, it’s worth discussing it with your healthcare professional rather than assuming you simply need a serum.
Gentle lash treatment: Rubbing your eyes, sleeping face-down, wearing waterproof mascara, and using harsh eye makeup removers all break natural lashes before they reach their full length. Stopping these habits alone can result in “growth” of an extra millimetre or two within a full lash cycle.
Removing extensions properly: Never pick, pull, or DIY-remove extensions. Every time you tear an extension off, you often tear the natural lash with it — which sets your lash growth back significantly. Professional removal costs $30–$80 and preserves your natural lash health.
Keratin lash lifts as an alternative: If your goal is fuller-looking lashes without extensions or serums, a keratin lash lift lifts your natural lashes upward from the base and adds keratin conditioning — the result is your natural lashes at their fullest, most beautiful potential. See The Complete Keratin Lash Lift Guide.
Give it time: Natural lashes take 60 to 90 days to complete a full growth cycle. Any product or lifestyle change needs at least 3 months of consistent use before you can honestly evaluate whether it’s working. Most people give up at 4–6 weeks and blame the product.
Our Honest Recommendation Framework
Here’s how we’d frame the decision when a client asks us at Posh Deluxe.
If you want dramatic lash growth and are informed about the risks: Prescription Latisse via your GP is the most-evidenced option. Understand the side effect profile fully before starting.
If you want moderate growth without a prescription: A reputable OTC serum with a synthetic prostaglandin analogue. Do a patch test first. Plan to use for 8–12 weeks, then evaluate.
If you want healthier, stronger lashes without growth-stimulating ingredients — including if you currently wear lash extensions: This is exactly what our Lash & Brow Serum was built for — oil-free, peptide-and-herbal based, safe with extensions, and gentle on sensitive eyes. Slower, cumulative results with essentially no risk profile.
If you’re pregnant, breastfeeding, or have any eye condition: Skip prostaglandin-based serums other than salon-supplied conditioners. Consult your GP if you’re unsure.
If you’ve been damaging your natural lashes (extension pulling, waterproof mascara, face-down sleeping): Fix the damage habits first. You’ll see more improvement from stopping the damage than from starting any product.
Common Serum Myths (Debunked)
“Castor oil grows lashes.” No — it conditions and moisturises. It doesn’t stimulate regrowth. It also destroys lash extension adhesive if you’re wearing extensions.
“Natural serums work better than the prostaglandin ones.” Actual growth data disagrees. “Natural” serums improve appearance modestly over time; prostaglandin serums cause more dramatic measurable growth. Whether that trade-off is worth the side effects is personal.
“If I stop using the serum, my lashes will fall out.” Not true. Your lashes will return to their natural cycle length. You just won’t be adding the growth-stimulating boost anymore.
“Lash serums thicken my brows too.” Sometimes. Peptide serums yes — our own serum is formulated for both lashes and brows. Prostaglandin serums — technically yes, but off-label use.
“I can use my prostaglandin serum with my lash extensions.” Yes, but poorly. Retention drops dramatically because the serum interferes with adhesive bonding.
“More expensive means more effective.” Not necessarily. Some premium brands are largely marketing. Read the ingredient list, not the packaging.
“I’ll see results in 2 weeks.” Unrealistic. Lash growth cycles are 60–90 days. Any product needs 8–12 weeks minimum for honest evaluation.
Frequently Asked Questions
Depends on which category. Prostaglandin-based serums (prescription or OTC) have documented long-term concerns including skin and iris darkening. Peptide-based conditioners like our own Lash & Brow Serum are generally safe long-term. Honest answer: nobody has 20+ year data on any of them.
Our own Lash & Brow Serum is what we use and recommend in-salon — it’s oil-free, made in Germany with a peptide-and-herbal formula, and safe for both extension wearers and sensitive eyes. If you’re specifically after prostaglandin-strength growth, that’s a conversation to have with your GP about prescription options.
Yes. Our oil-free peptide serum can be used right up to your appointment. If you’re using a prostaglandin-based product, let your lash artist know before your appointment so they can advise you based on the specific product you’re using and your natural lash condition.
Peptide/conditioning serums like ours: around 6 weeks (42 days) for visible improvement in length and density, per usage guidelines. Prostaglandin serums: 8–12 weeks for length and density increase. Give any product the full recommended window before deciding it doesn’t work.
Not directly. They may support faster regrowth, but the underlying damage habit needs to stop first. Professional removal and 6–8 weeks off extensions does more for lash health than any serum.
Not necessarily — they’re just doing something different. They condition and support healthy growth rather than force it chemically. If you want healthier-looking lashes without prostaglandin exposure, they’re a reasonable choice with realistic expectations, and it’s exactly the category our own serum sits in.
Skip prostaglandin growth serums for the wearing period. An oil-free peptide serum like ours is safe once the initial 48-hour cure window is complete.
Rarely with topical OTC serums. Documented risk with prescription Latisse, especially in light-eyed users. Our serum contains no prostaglandin ingredients, so this isn’t a concern with it. If you have blue, green, or hazel eyes and this concerns you generally, avoid prostaglandin-based serums.
It depends on how the product is classified. Cosmetics and therapeutic goods are regulated differently in Australia, and the claims made about a product can affect how it is classified. Prescription lash-growth treatments are subject to different requirements from cosmetic lash-conditioning products.
Properly applied and maintained, no. Poorly applied, incorrectly weighted, or repeatedly damaged by DIY removal — yes, dramatically. This is why professional removal and skilled application matter so much.
The Bottom Line
Lash growth serums are real, they can work, and they’re also more complicated than the beauty aisle marketing suggests. The most important thing is being informed — understanding what ingredient you’re putting on your eye area, what it actually does, and whether the trade-off is right for you.
At Posh Deluxe Salon in Mount Pleasant, we help our clients make informed choices about their natural lash health — not just their extensions. That’s why we formulated our own Lash & Brow Serum: an oil-free, German-made, peptide-and-herbal formula designed to complement your lash-care routine, including for clients who wear lash extensions and prefer to avoid prostaglandin-based formulas.
If you’re considering a lash serum and unsure which category is right for you, book a free consultation with our award-winning team. We’ll assess your natural lash strength honestly and recommend the safest path to your goals — whether that’s our serum, a break from extensions, a keratin lash lift, or simply protecting the lashes you already have.
Shop the Posh Deluxe Lash & Brow Serum →
Book your free lash consultation with our team today, or get in touch with us for a chat first.
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