The Ultimate Guide to Lash Serums
Table of contents
Lash serums have become one of the most talked-about products in the beauty industry — and for good reason. When used correctly, they don’t just improve lash health; they dramatically boost the visible results of lash lifts and can become one of the most profitable products in your salon. But despite their popularity, most lash artists and clients misunderstand how they work — or worse, use formulas that can harm eye health.
Whether you’re a lash artist, a salon owner, or just curious about growing better lashes, here’s what you need to know — including how lash serums elevate lash lift results and boost your bottom line when recommended correctly.
The Science of Lash Growth
Lashes grow in three phases:
- Anagen (growth): \~1–2 months
- Catagen (transition): \~2 weeks
- Telogen (rest & shed): \~2–3 months
Growth only happens during anagen, and prostaglandin lash serums work by artificially elongating this phase — keeping lashes growing longer before naturally falling out.
✅ What Lash Serums Can Do:
- Extend growth phase from \~4–10 weeks to \~8–12 weeks (prostaglandin serums)
- Improve follicle environment for more efficient keratin formation (peptide serums)
- Add apparent thickness through hydration or film-formers (peptide serums)
❌ What Lash Serums Can’t Do:
- Create new follicles or increase total lash count
- Deliver dramatic changes in 1–2 weeks
- Maintain effects without consistent daily use
4 Types of Lash Serums Based on Their Active Mechanism (and What They Actually Do)
Prostaglandin Analogues
The first lash serums weren’t invented in a beauty lab — they were discovered accidentally. Glaucoma patients using eye drops noticed that their lashes were growing longer. The drug? Bimatoprost, a synthetic analogue of prostaglandin, which lowers intraocular pressure.
Cosmetic brands quickly seized the opportunity and people started using bimatoprost off-label for lash growth. It worked — but not without a cost. Using it in healthy eyes meant changing normal eye pressure and causing a host of serious, often irreversible side effects.
What is Glaucoma?
Glaucoma is a medical condition where the pressure inside the eye (called intraocular pressure or IOP) becomes abnormally high. If untreated, this pressure can damage the optic nerve and lead to permanent vision loss. Medications like bimatoprost are prescribed to lower this pressure — and that's how their lash growth side effects were first discovered.
Known Side Effects:
- Changes in intraocular pressure (pressure inside the eyes)
- Iris pigmentation (light eyes may turn darker)
- Eyelid and periorbital (skin around the eyes) darkening
- Sunken eyes due to periorbital fat loss
- Eye redness, burning, dryness, and itchiness
- Dry-eye symptoms (especially problematic for contact lens users)
- Misdirected or spidery lash growth from the shortened telogen phase
When these side effects were discovered, regulatory bodies banned bimatoprost from use in cosmetic products. But manufacturers didn’t stop — they created derivatives aka analogues (slightly modified copies of the original ingredient to avoid regulations that still have the same risks).
What are the most common prostaglandin analogues in lash serums?
❗️Ethyl Tafluprostamide
❗️Latanoprost
❗️Travoprost
❗️Tafluprost
❗️Noralfaprostal
❗️Methylamido-Dihydro-Noralfaprostal
❗️Isopropyl Cloprostenate
❗️Trifluoromethyl Dechloro Ethylprostenolamide
❗️Isopropyl Phenyl Hydroxypentane
❗️Dihydroxy Cyclopentyl Heptane
❗️Dechloro Dihydroxy Difluoro
❗️Ethylcloprostenolamide (DDDE)
Look for "-prost" in the INCI list to spot these hidden analogues.
Peptide-Based Serums
Peptides are short chains of amino acids — the building blocks of proteins like keratin. In lash serums, they act like biological messengers, telling the lash root to:
- Strengthen keratin production
- Prevent premature shedding
- Improve elasticity and moisture retention
- Increase lash diameter through hydration
They don’t stimulate new growth but enhance the quality of existing lashes with no adverse effects.
Example actives: Myristoyl pentapeptide-17, Myristoyl hexapeptide-16
Botanical Supportive Serums
These serums don’t extend the growth phase but hydrate, nourish, and protect existing lashes. Typical ingredients include:
- Panthenol, glycerin (humectants)
- Film-formers and emollients
Perfect for:
- Post-lamination aftercare
- Sensitive clients
EGF-Activating Serums (EGF boosters)
Epidermal Growth Factor (EGF) is a naturally occurring protein that signals skin and hair follicles to regenerate. Production declines with age — leading to sparse, sluggish lash and brow growth, often due to follicles entering a prolonged resting state known as telogen arrest.
EGF-activating serums work by reawakening dormant follicles:
✅ Stimulate keratin and melanin production
✅ Trigger growth in follicles stuck in telogen arrest (a condition where hair follicles remain in the resting phase instead of cycling back into active growth, leading to thinning or sparse lashes and brows)
✅ Result: new hair growth in bald spots and visibly denser lashes
Why is it different?
✅ Can start growth in inactive follicles (others can’t)
✅ 100% natural versions exist using plant-based actives
Our Lash & Brow Filler contains botanical EGF activators (not synthetic proteins, not prostaglandins).
Post-Lamination Aftercare
First 48 Hours:
❌ No oils or oily serums (they interfere with disulfide bond reformation)
✅ Wait 24h after lash lift or 48h after brow lamination before applying non-oily serums
Impact of Serum Types:
- Prostaglandin: Lashes grow too fast → lash lift curl drops by ~2 weeks to just 4–6 weeks
- Peptide: Strengthens lashes; doesn't affect lash lift retention
- EGF: Uneven new growth early on so lifts are required more frequently; stabilizes after 2–3 months so lash lift retention is no longer affected
Educating Clients & Retailing the Right Way
Retailing lash serums to your lash lift customers is highly recommended — it enhances the look of their lift and adds to your bottom line. But it’s not just about the sale: it's also about trust and long-term results.
Clients rely on you to guide them toward safe, effective options. By educating them about how serums really work, you help them avoid disappointment, wasted money, or even harm from using the wrong products.
I don’t recommend retailing serums to lash extension customers — they’ll only cause faster grow-out, not stronger lashes. The only exception: clients with lashes too short to support the extensions they want.
Read the blog post about the differences between growing lashes longer vs. stronger here.
Retail Smart: What to Recommend (and What to Avoid)
❌ Avoid Recommending:
- Prostaglandin-based serums: High risk, short-term thinking
- Any product using vague marketing and no INCI disclosure
✅ Best for Retail:
- Peptide serums: Safe, nourishing, no regulation issues
- EGF boosters: Excellent for sparse brows or lashes
Want to increase your revenue with retail?
Don’t Fall for Marketing Tricks
Questionable marketing you can see online:
- Influencers claiming miraculous results in 7 days. This is physiologically impossible.
- "4-week transformations" that involve lash extensions. Pay attention to the inner corners and roots of the lashes and you can notice which lashes have been extended.
- Lashes plucked out for the "before" photo to exaggerate results. Only EGF boosters start new growth in previously bald spots - regular lash serums don't.
Final Thoughts
Lash serums can be incredibly effective — or incredibly misleading. Understanding the real science behind how they work (and what they can’t do) helps you:
- Educate clients
- Protect their lash health
- Elevate treatment results
- Build trust
- Grow your retail income responsibly
How to Use Lash Serums
It’s enough to use lash serums once a day because the active ingredient is so potent that using it once a day is enough to make lashes grow. Use it at night (after removing makeup) as your body restores itself overnight the most. Using it twice won’t make lashes grow faster — it will only deplete your product faster.
As long as the product is full enough, you don’t have to double dip – there is enough product on the wand for both eyes. Swipe once on the upper lash line – blinking transfers enough product to the bottom lash line. Only when you feel that your product is getting low in the tube, double dip for the second eye.
