The lash serum guide
Can a Lash Serum Change Your Eye Colour? The Ingredient to Check
Some lash serums can. The ones that do contain prostaglandin analogues — an ingredient class borrowed from glaucoma medicine, where the lash growth was originally a side effect. The American Academy of Ophthalmology is direct about the trade-off: eye redness and darkened eyelid skin go away when you stop, but darkening of the iris "cannot be reversed". A serum without that ingredient class has no mechanism to change eye colour at all, and in Canada it should not have one anyway: Health Canada lists prostaglandins and their analogues as prohibited in cosmetics. Below is how to read a label, what to expect, and the eight-week routine.
What is actually in most lash serums
The modern lash serum exists because of an accident. Prostaglandin analogues were developed to lower pressure inside the eye in glaucoma, and patients using the drops kept reporting the same unexpected thing: their eyelashes were getting longer, thicker and darker. One of those molecules, bimatoprost, was subsequently studied and approved for lashes on its own account, and it remains — according to the American Academy of Ophthalmology — the only eyelash growth product with FDA approval.
What happened next is the part worth understanding. The effect was real, the molecule was known, and a cosmetic version was an obvious commercial opportunity. So closely related analogues began appearing in serums sold on beauty shelves rather than by prescription. The AAO names isopropyl cloprostenate as the one most often found in over-the-counter products, and is blunt about what that means: it is not FDA approved, and "because these over-the-counter serums have not been FDA tested, their safety and effects are not known."
This is why label-reading matters more here than in almost any other beauty category. Two serums on the same shelf, at similar prices, in similar packaging, can work by completely different mechanisms — one by conditioning the lash you have, the other by pharmacologically extending the growth phase of the follicle. Nothing on the front of the bottle reliably tells you which.
Canada draws the line in a specific place, and it is worth knowing where. Health Canada’s Cosmetic Ingredient Hotlist lists "prostaglandins, their salts, derivatives and analogs" as prohibited in cosmetics — added in April 2014, on the stated grounds that they appear on the Prescription Drug List and have solely therapeutic functions. A lash serum legally sold as a cosmetic in Canada should therefore not contain one at all. The catch is that plenty of people buy serums from cross-border marketplaces, where that line does not apply, which is exactly the situation in which reading the ingredient list is not optional.
What is reported — and what does not go away
These effects are associated with the prostaglandin-analogue class, not with every serum and not with every user. The distinction that matters to anyone deciding is not how common they are, but which ones reverse when you stop.
Reverses when you stop
- Redness and irritation of the eye. The AAO describes eye redness and irritation as effects that "disappear after discontinuing the drug".
- Darkening of the eyelid skin. Also listed as resolving after stopping — the pigment change is in the skin of the lid rather than in the eye itself.
Does not reverse
- Darkening of the iris. This is the one that makes the category worth thinking about at all. In the AAO’s words: "Darkening of the iris (the colored portion of the eye) has also been reported, and this side effect cannot be reversed." It is more often described in lighter and mixed-colour irises, and it is a change to the eye, not to make-up.
There is a second, less-discussed effect that has been reported with prolonged use of this class around the eye: a loss of fat volume in the tissue surrounding the eye, which can leave the upper lid looking hollowed or the eye more deep-set. It is the subject of ophthalmology literature rather than of marketing copy, and it is one of the reasons the class is treated as a medicine rather than a cosmetic.
None of this makes prostaglandin analogues indefensible. Bimatoprost is an approved drug, it works, and for someone who wants that result and understands the trade-off it is a legitimate choice made with a prescriber. The problem the AAO points at is narrower and sharper: the same class turning up in untested cosmetic products, where nobody has quantified the dose, the exposure or the risk, and where the buyer is not told they are making that trade at all.
The practical conclusion is unglamorous. If a serum contains no prostaglandin analogue, there is no mechanism by which it could change your iris — not a smaller risk, no mechanism. That is a claim about chemistry rather than about a brand, and it is checkable on any label in about thirty seconds.
How to read a lash serum label in thirty seconds
Ingredient lists are legally required and are usually on the carton rather than the bottle. You are looking for one family of names, and they are not disguised — they are simply long enough that most people skip them.
Look for anything ending in -prost
Bimatoprost, latanoprost, travoprost, tafluprost. These are the prostaglandin analogues used in ophthalmology. Their presence in something sold as a cosmetic is the thing to notice, because in Canada that class is prohibited in cosmetics outright.
And anything containing "cloprosten"
Isopropyl cloprostenate is the one the American Academy of Ophthalmology names as the analogue most often found in over-the-counter serums. You may also see cloprostenol isopropyl ester, or the long-form dechlorodihydroxydifluoro ethylcloprostenolamide, which is the same family written at maximum length.
Do not rely on the front of the pack
"Hormone-free", "clean", "natural" and "clinically tested" are not regulated in a way that answers this question, and a serum can be all four and still contain an analogue. The INCI list is the only place the answer is guaranteed to be. If a product does not publish one, that is itself an answer.
What a conditioning serum looks like instead
Peptides, panthenol, hyaluronic acid, proteins, biotin, plant extracts. These work on the lash and the surrounding skin rather than on the follicle’s growth phase, which is why they are slower and why they are sold as cosmetics. MAVALA Double-Lash sits here: a vitamin tripeptide with panthenol, plus a nutritive extract rich in proteins, hyaluronic acid and collagen, at 96% ingredients of natural origin.
Check where you are buying, not just what
Health Canada’s prohibition applies to cosmetics sold in Canada. A serum ordered from an overseas marketplace has not necessarily been assessed against that list, and imported listings frequently carry ingredient information that does not match the product in the box. Buying from a Canadian retailer is not a guarantee of anything by itself, but it does mean somebody is accountable for the label.
The 8-week routine
Eight steps, three of which are about removing make-up rather than applying serum — which is roughly the right ratio.
Take every trace of make-up off first
A conditioning serum has to reach the lash and the lash line, and mascara is specifically engineered to stay put. Use a dedicated eye make-up remover rather than a face cleanser, and a bi-phase or gel remover if you wear waterproof — the alternative is rubbing, and rubbing pulls lashes out faster than any serum replaces them.
Wait until the lid is properly dry
Applying onto skin that is still damp with remover dilutes the serum and spreads it where it is not wanted. Thirty seconds is usually enough. If you use an eye cream, put the serum on first and the cream afterwards.
Apply once a day, in the evening
MAVALA’s instruction for Double-Lash is once daily, preferably at night, on clean make-up-free lashes. Evening is not superstition: the lashes are bare for eight hours, nothing is being applied over the top, and you are not rubbing your eyes.
Brush it through as you would a clear mascara
Double-Lash uses a mascara-style brush, so the motion is familiar: from the base of the lashes outwards, upper lid only, both eyes. The base matters more than the tips — that is where the lash meets the skin and where a conditioning formula has something to work on. It can be brushed through the brows too.
Use a sensible amount, not a generous one
One pass per eye. More product does not accelerate anything, and excess migrating into the eye is the most common cause of the irritation people then blame on the formula. If any gets in, rinse with water rather than pressing at it.
Keep wearing make-up if you want to — over the top, not under
The serum goes on bare lashes at night; mascara goes on in the morning. There is no need to give up eye make-up for two months, which matters, because the routines people abandon are the ones that ask them to look worse in the meantime. A lash-care mascara with silk proteins is a reasonable thing to be wearing during a treatment period.
Give it seven to eight weeks before you judge it
MAVALA states first results from 30 days of daily use and clinically proven efficacy from seven weeks. That is not a hedge — it is the lash growth cycle, explained in the next section. Judging at three weeks is judging before the lashes that were treated from day one have finished growing.
Then keep going, or stop and watch
A conditioning serum does not permanently change the follicle, so lashes gradually return to their own baseline once you stop. That is the honest counterpart to it having no drug-like mechanism. Most people either continue at a reduced frequency or run it as a course a couple of times a year, typically after a period of extensions or heavy waterproof mascara.
What to expect, and why it takes this long
Weeks 1–2
Conditioning, not growth
What changes early is the lash you already have: better hydrated, a little more flexible, less inclined to snap when you curl or remove mascara. That is worth having — a lash you do not break is a lash you keep — but it is not new growth, and reading it as new growth is how people end up disappointed later when the effect appears to stall.
Weeks 3–4
The part where nothing seems to happen
Here is the mechanism nobody explains. An eyelash spends only about four to ten weeks in its active growing phase, and at any given moment your lash line is a mix — some growing, some resting, some about to fall. A serum can only influence a lash that is currently growing, so in the first month it is working on a minority of your lashes. MAVALA states first results from 30 days, and this is why that is the earliest honest number rather than a conservative one.
Weeks 5–7
Enough of the lash line has turned over to see it
By now the lashes that entered their growth phase around the time you started have finished growing, and enough of them have done so at once to read as a difference rather than as imagination. MAVALA gives this as the point of clinically proven efficacy: from seven weeks of daily use. If you are going to form a view, form it here.
Week 8 and beyond
The full cycle, and what maintenance looks like
A whole eyelash lives somewhere between about four and eleven months from appearing to falling out, so even at eight weeks you have not yet seen a complete turnover of the lash line — the effect continues to accumulate for a good while after the point at which you first notice it. Beyond that it is maintenance: the same application at a reduced frequency, or a repeated course, since a conditioning serum works for as long as you use it and not afterwards.
What to use
A lash routine is four things, and only one of them is the serum. Two of the others are about not losing the lashes you already have, which is the half most people skip.
THE SERUM · Lashes that are short, sparse or brittle
a prostaglandin-free lash serumBrushed onto make-up-free lashes once a day, preferably at night. The actives are a vitamin tripeptide with panthenol and a nutritive extract rich in proteins, hyaluronic acid and collagen, at 96% ingredients of natural origin; free from mineral oil, phthalates, SLS, parabens and fragrance, and ophthalmologically tested. First results from 30 days, clinically proven efficacy from seven weeks. It contains no prostaglandin analogue, which is the whole point of everything above.
THE SERUM · Brows thinned by years of plucking or waxing
a brow serum without hormonesThe same logic applied to eyebrows, which have their own growth cycle and their own reason for thinning. 93% ingredients of natural origin, with turmeric-derived plant exosomes, resurrection plant extract and mastic tree resin; ophthalmologically and dermatologically tested. Morning and evening on clean brows. Also prostaglandin-free, for the same reason.
THE LOSSES · Rubbing mascara off at the end of the day
a gentle eye make-up removerThe least interesting product here and quite possibly the one that changes the most. Mascara that will not come off gets rubbed off, and mechanical pulling removes lashes faster than any serum grows them. It also matters for the routine itself: a serum cannot reach a lash still coated in yesterday’s mascara.
THE LOSSES · Waterproof mascara, specifically
a remover made for waterproofWaterproof formulas are designed to resist water, so removing them with a water-based lotion means friction, and friction is the problem. A dedicated waterproof remover is the difference between dissolving the mascara and dragging at the lash. If you wear waterproof daily, this is not an accessory.
MEANWHILE · What to wear during the eight weeks
a mascara enriched with silk proteinsYou do not have to stop wearing eye make-up while you treat your lashes, and being told to is one of the reasons people abandon a routine in week two. The serum goes on bare lashes at night; mascara goes on over the top in the morning. Choosing one formulated as lash care rather than purely as colour is the small optimisation available here.
If you wear, or have worn, lash extensions
Two different questions get asked here and they have different answers, so it is worth separating them.
The first is whether a serum will loosen a set you are currently wearing. What degrades cyanoacrylate — the adhesive used for extensions — is oil, which is why lash technicians tell clients to avoid oil-based cleansers and oily eye creams. MAVALA Double-Lash is water-based and contains no mineral or plant oils, so it does not present that particular problem. Beyond that, how long any set lasts depends on the adhesive, the technician and your own lash cycle far more than on what you brush through in the evening.
The second question is the one worth more. Extension wear is hard on natural lashes, partly from the weight and partly from the removal, and people frequently arrive at a lash serum precisely because a set has just come off and what is underneath is thinner than they remembered. That is a good moment for a conditioning serum and a bad moment for another set — the natural lash needs a full cycle to come back, and a cycle is months, not weeks.
If you are between sets, the useful move is to treat the gap as the treatment window rather than as a wait: nightly serum, gentle removal, and no curling of lashes that are already fragile. If you are going straight back into extensions, at least go back into them on lashes that have been conditioned rather than on the ones that were just stripped.
Also a guide: Why your nails aren’t growing — the 6-week night routine
What to use
Four jobs: the serum, the brows, the removal, and what you wear meanwhile.
Questions people ask before they start
A serum containing prostaglandin analogues can. That ingredient class comes from glaucoma medicine, and the American Academy of Ophthalmology states that darkening of the iris has been reported and "this side effect cannot be reversed" — unlike eye redness and darkened eyelid skin, which resolve after stopping. A serum with no prostaglandin analogue in it has no mechanism to do this at all. In Canada the question is partly settled by regulation: Health Canada lists prostaglandins and their analogues as prohibited in cosmetics, so a lash serum legally sold here as a cosmetic should not contain one.
Read the ingredient list, which is usually printed on the carton rather than the bottle, and look for two patterns. Anything ending in -prost — bimatoprost, latanoprost, travoprost, tafluprost — and anything containing "cloprosten", most commonly isopropyl cloprostenate, which the AAO names as the analogue most often found in over-the-counter serums. Front-of-pack wording will not answer this: a serum can say hormone-free, clean and clinically tested and still contain an analogue. If a product publishes no ingredient list at all, treat that as the answer.
They work differently and more slowly, and it is worth being straight about the trade-off. A prostaglandin analogue acts pharmacologically on the follicle to extend the lash’s growing phase; a conditioning serum works on the lash and the surrounding skin with peptides, panthenol, proteins and hyaluronic acid. The second is a cosmetic effect and it takes a cycle to show — MAVALA gives first results from 30 days of daily use and clinically proven efficacy from seven weeks. It also stops when you stop, because nothing has been permanently altered. What you get in exchange is no mechanism for iris change and no prescription-strength molecule near your eye.
Because of the lash growth cycle rather than the formula. An eyelash spends only about four to ten weeks in its active growing phase, and your lash line is always a mix of lashes growing, resting and about to fall — so in the first month a serum is only influencing the minority currently growing. Enough of the line has turned over by around weeks five to seven for the difference to read as real, which is why MAVALA states clinically proven efficacy from seven weeks. A whole lash lives roughly four to eleven months, so the effect keeps accumulating well past the point you first notice it.
It depends entirely on which kind. The effects most often reported with prostaglandin analogues include redness and irritation of the eye, which is exactly the wrong starting point for someone already prone to it. A conditioning serum has a different risk profile, and the things to check are whether it is ophthalmologically tested, whether it is fragrance-free, and what else has been left out — MAVALA Double-Lash is ophthalmologically tested and free from mineral oil, phthalates, SLS, parabens and fragrance. Two practical points regardless of product: apply one pass per eye rather than a generous amount, since most irritation comes from excess migrating into the eye, and if you wear contact lenses or have an existing eye condition, ask your optometrist or ophthalmologist first.
What breaks down cyanoacrylate extension adhesive is oil, which is why technicians warn against oil-based cleansers and rich eye creams. MAVALA Double-Lash is water-based and contains no mineral or plant oils, so it does not present that problem. How long a set actually lasts depends far more on the adhesive, the technician and your own lash cycle. The stronger reason to own a serum, though, is for afterwards: extension wear leaves natural lashes thinner, and the gap between sets is the useful treatment window rather than a wait.
The growth cycle and the reason for the thinning, mostly. Brow hairs run on a different and generally longer cycle than lashes, and the commonest cause of sparse brows is repeated plucking and waxing damaging the follicle over years rather than anything happening now. MAVALA makes both — Double-Lash for lashes, applied once a day at night, and Double-Brow for brows, applied morning and evening with a different formula built around plant exosomes, resurrection plant extract and mastic tree resin. Both are prostaglandin-free. Double-Lash can be brushed through the brows as well, but the brow serum is the one designed for them.
With a conditioning serum, yes — gradually, over a cycle or two, as treated lashes are replaced by untreated ones. That is the honest counterpart to it working cosmetically rather than pharmacologically: nothing about the follicle has been permanently changed, so nothing permanently remains. It is not a reason to avoid one, but it is a reason to think of it as a routine rather than a course of treatment with an end date. Most people either continue at a lower frequency or repeat it as a course after periods that are hard on lashes — extensions, daily waterproof mascara, a stressful stretch.
MAVALA CARES
We care about the planet. We aim to minimise our impact on the environment through the following measures:
Ingredients
We source our ingredients and raw materials from the nearest suppliers in Switzerland to reduce our carbon footprint. We also increasingly use ingredients that are readily biodegradable. In particular, we do not use plastic microbeads nor cyclopentasiloxane (D5), which contribute to ocean pollution.
Packaging
Whenever possible, we package our products without a box or cellophane and in recycled and recyclable materials (including plastic and glass) to reduce waste. We have also implemented clear labelling on product packaging to assist you in knowing which part of the packaging can be recycled and how.
Manufacturing
Whenever possible, we manufacture under cold conditions to reduce energy consumption. We are also implementing strict waste separation and recycling processes in our production site and warehouses, including that of our Canadian distributor.
