Peptide serums for eyelashes and brow products are often advertised as cosmetics that make eyelashes or eyebrows appear fuller, thicker, thicker, or longer. However, these terms do not necessarily mean that the product actually stimulates the growth of new hair. Existing eyelashes may appear longer or thicker because they are better nourished, darker, less prone to breakage, differently styled, or simply more visible. Even if an increase in measured eyelash length is noted in a clinical study, a proper comparison is still needed before the change can be reliably attributed to a specific peptide or other ingredient.
This distinction is important because improving the condition of existing hair, extending the visible duration of its retention, and changing the biological activity in the hair follicle are different effects. A cosmetic product can improve the condition of eyelashes without showing that it leads to the formation of new hair follicles or clinically proven stimulation of hair growth.
There are direct clinical studies of some eyelash preparations containing peptides, including small open-label studies. However, these evidence should be evaluated independently of the studies of prostaglandin analogues, which belong to a different chemical and pharmacological group. Similarly, studies combining topical preparations with treatments such as microblading involve an intervention different from the simple use of serum.
Therefore, when evaluating a product for eyelashes or eyebrows, it is worth asking four basic questions: what exactly was used, where the product was applied, what effect did it actually change, and does the design of the study allow the change to be attributed to the entire product or a specific component?
What do peptide products for eyelashes and eyebrows contain?
The term „peptide” does not mean a single standardized formulation
A peptide is a chain of amino acids; however, the peptides used in cosmetics can vary significantly in sequence, size, chemical modifications, and proposed biological function.
Eye serum, simply referred to as „peptide serum”, can contain a single peptide, several peptides, or a complex mixture in which the peptides constitute only part of the entire formulation. The remaining ingredients may include glycosaminoglycans, humectants, plant extracts, conditioning agents, film-forming components, preservatives, and other active ingredients.
For this reason, this ready-made cosmetic formulation must be treated as a real intervention that is subject to testing.
The isolated peptide evaluated in the laboratory is not the same as the ready-made cosmetic serum containing this peptide along with many other ingredients.
An open clinical study published in 2024 evaluated serum for eyelashes containing peptides and glycosaminoglycans. The study included 30 women and the observation period was 12 weeks. The researchers evaluated several parameters related to the appearance and structure of eyelashes. [1]
This constitutes direct clinical evidence regarding the specific formulation being studied.
However, this does not mean that every product labeled as „peptide serum for eyelashes,” „peptide complex,” or „peptide technology for eyelashes” will provide the same results.
In another 90-day study, multi-component serum containing growth factors was evaluated in 30 women, 29 of whom completed the study. [2] Since the intervention involved many components, the results relate primarily to the finished product rather than to the independent action of a single designated component.
A similar interpretational problem arises in the case of other multi-component peptide cosmetics. We discuss it in more detail in the article Multipeptide serum.
Not every mascara serum is a peptide product
The category „eyelash serum” includes products with a very diverse composition.
Some contain peptides. Others are based primarily on conditioning substances or plant compounds. Some may contain prostaglandin analogs or related compounds that differ chemically and pharmacologically from peptides.
A good example is bimatoprost.
In a randomized, controlled study involving 278 participants, improvement in certain eyelash parameters was observed after the use of bimatoprost [3].
This is significant evidence regarding bimatoprost in the context of this particular study.
However, this is not evidence that can be applied to a cosmetic product that contains only peptides.
Similarly, the presence of a peptide highlighted on the label does not mean that it is the only potentially active ingredient in the product. The formulation may combine peptides with other biologically active substances.
Therefore, the complete composition of the product is much more important than the general name of the category visible on the packaging.
Different groups of ingredients may also be associated with different questions regarding the mechanism of action, tolerance, and safety.
„Eyelash serum” therefore describes the type of product and the place of its use, rather than a common mechanism of action, a standardized safety profile, or an identical level of clinical evidence.
Evidence regarding eyelashes and eyebrows should relate to a specific location
Eyelashes and eyebrows are hair, but they occur in different anatomical locations and may require evaluation using other parameters.
The product tested specifically on eyelashes does not automatically provide evidence of brow regrowth or an increase in their density.
Similarly, studies regarding eyebrows do not automatically confirm an increase in eyelash length.
In studies of bimatoprost for eyebrows, the density of hair and the diameter of the hair shaft were separately evaluated, among other things.[4]
This study does not provide evidence regarding peptides. Its significance is methodological: it shows why questions regarding the eyebrows require measurements specific to that area.
The studies of hair and scalp skin are even further removed from claims regarding eyelashes or eyebrows.
Therefore, the results of the hair study on the head should not be presented as evidence of the effectiveness of eyelash serum simply because the products contain the same or similar ingredients.
The peptide mixture is not an automatically defined preparation that stimulates hair growth
The number of peptides listed in the composition does not determine the effectiveness of the product.
Marketing terms such as „multipeptide complex”, „five-peptide system” or „growth factor mixture” provide little scientific information unless we know the specific ingredients, their concentrations, the properties of the formulation and the evidence regarding the finished product.
A product containing more peptides is not automatically more effective than a product containing fewer of them.
Similarly, the presence of „growth factors” or ingredients referred to as growth factor-related does not prove that the molecules remain chemically stable in the finished product, reach the appropriate biological target, or lead to clinically measurable hair growth.
The proposed mechanism may serve as a justification for conducting research.
However, it is not proof that the finished cosmetic product actually produces such an effect in humans.
A similar caution should be exercised with the term „natural”.
Plant extract may contain many different chemical substances, the proportions of which may additionally vary between preparations. A mixture described as natural may be less chemically defined than a single characterized peptide.
Neither the natural nor the synthetic origin of the ingredient itself determines its effectiveness.
Each ready-made formulation requires evidence corresponding to its actual composition and intended use.
Conditioning eyelashes and stimulating hair growth are different claims
Existing eyelashes can look different without the formation of new follicles
Contouring can noticeably change the appearance of existing lashes.
The formulation can cover the surface of the hair, improve its smoothness, change the way light is reflected, increase the visible separation between adjacent lashes, or limit their mechanical breakage.
Each of these effects can make the eyelashes look fuller or healthier.
Restricting breakage can also make existing lashes appear longer because fewer hairs will break before reaching their potential length.
However, this is not the same biological process as the stimulation of the hair follicle to produce additional hair.
This does not mean that conditioning effects are unimportant.
The cosmetic product can provide real improvement in appearance without stimulating the activity of the hair follicles.
The most important thing is that the way the product’s action is described corresponds to what was actually demonstrated.
Therefore, a product that improves the condition of eyelashes should not be automatically described as causing the formation of new follicles or stimulating the growth of new eyelashes.
On the other hand, improvements in appearance should not be ignored just because they do not confirm the formation of new follicles. They should simply be described at a level consistent with the evidence.
The most important distinction concerns the improvement of the appearance, condition or maintenance of existing hair, and the demonstration of a biological change in the hair production process.
These are different questions that require different research methods.
The length, number, thickness, and darkness of the eyelashes are separate parameters
The appearance of eyelashes is multifaceted.
The eyelash may appear longer because the length of the hair has actually increased, but its appearance can also change under the influence of the curvature, the angle of arrangement, the separation of adjacent hairs, pigmentation, or better visibility of the tip.
Therefore, the study of eyelash length requires standardized imaging and a clearly defined measurement method.
In a 2024 study involving a preparation containing peptides and glycosaminoglycans, several eyelash parameters were measured separately, including their number, width, length, volume, curvature, and angle.[1]
This is useful because it allows us to avoid treating all visible changes as a single effect.
Because this was an open „before and after” study, it cannot be used to completely determine which component was responsible for each change, nor can it rule out all possible influences of natural variability, care practices, or participants’ expectations.
Similarly, an increased number of visible eyelashes does not prove that new anatomical hair follicles have formed.
Previously faint-appearing hair can become easier to notice. Existing follicles can also go through different phases of the natural hair cycle.
The surface image showing a higher number of detectable hairs therefore confirms a higher number of visible eyelashes under the given measurement conditions.
It does not independently confirm the formation of new follicles.
The claim that a cosmetic product creates new hair follicles would require much stronger anatomical and biological evidence.
The overall assessment of the appearance of the eyelashes is not a direct measure of growth.
Some studies use a global scale to assess the size of the eyelashes or their visibility.
Such a scale can be clinically useful because it provides a structured way to assess the overall visibility of eyelashes.
However, it should not be interpreted automatically as a direct measure of growth rate or the number of hair follicles.
Several characteristics can influence a better assessment at the same time.
Darker, thicker, longer, more curved or better separated eyelashes can all achieve a higher visual rating.
In a controlled study of bimatoprost, the overall assessment of eyelashes was combined with digital measurements of several of their characteristics.[3]
This shows the advantage of evaluating many parameters instead of basing the entire conclusion on a single overall visual result.
However, these evidence still applies to bimatoprost and the formulation under investigation.
They should not be presented as evidence regarding a serum peptide unrelated to them.
The density of the eyebrows requires its own definition
The term „fuller lips” can mean several different visual changes.
More hair may be visible in a particular area. Existing hair may become thicker or darker. The way you care for and style your eyebrows can also affect the amount of skin visible between them.
Therefore, the brow density measurement requires the use of a constant anatomical area and a consistent measurement method.
Studies that separately report hair density and the diameter of the hair shaft provide more useful information than a single result regarding the participants’ satisfaction.[4]
Even an objectively measured increase in apparent density does not, however, prove that completely new hair follicles have formed.
Existing follicles may produce more visible hair, and changes in stem thickness or pigmentation can affect apparent density.
The satisfaction of the participants also provides valuable information, but subjective assessments should not replace objective measurements when formulating biological claims regarding hair growth.
The duration of the study and the method of measurement are important
The observation period should correspond to the claimed claim
Changes related to hair develop over time.
Immediate cosmetic change after using the serum cannot be evidence of new hair growth, because biological hair growth takes time.
A study lasting several weeks may make it possible to detect changes occurring during product use.
The improvement measured during the period when the participants continue to use the serum does not, however, mean that the effect will persist after discontinuation of the serum.
In the study, serum containing growth factors was observed in the participants for 90 days after the product was administered. [2]
The positive result during the last visit therefore shows what has been observed during that period.
It does not confirm the durability of the effect.
To demonstrate its persistence, researchers should plan an observation period after discontinuation of the product and check whether the measured change still occurs.
The same principle applies to claims about how quickly a product „works”.
If a difference was observed in one study during a specific week, this does not mean that all peptide eyelash serums have a universal effect.
The formulation, the population studied, the initial characteristics of the eyelashes, and the sensitivity of the measurement can all influence the moment at which a change becomes detectable.
Standardized photos are important, but not enough
Photography is often used in cosmetics research for eyelashes and eyebrows, but the high quality of the photo itself does not guarantee reliable measurement.
The positioning of the camera, lighting, magnification, eyelid adjustment, and the area being analyzed should remain as constant as possible between visits.
Other cosmetic procedures are also important.
Eyelash tinting, dyeing, extension, eyelash lifting, brow makeup, and how they are cared for can all affect the visible length, darkness, curve, and density.
These factors should be controlled, limited, or precisely documented.
Researchers must also determine what they mean by „length of eyelashes”.
Measuring the longest visible eyelash is not the same as calculating the average length of several hairs. Measuring selected individual lashes differs from computer analysis of the entire area.
The same method should be applied consistently.
High-resolution imaging software can increase precision, but it won’t compensate for poorly taken photos or a biased selection of material.
An advanced algorithm also does not eliminate the risk of error if favorable images are selected inconsistently or the analysis criteria change between visits.
The control group helps to separate the product’s performance from the changes that occur over time.
Controlled studies are particularly valuable when we want to determine whether the observed change actually resulted from the intervention.
A properly matched substrate can take into account some of the effects resulting from the product base itself and regular application.
Randomization can reduce systematic differences between the groups being compared.
Blindfolding, on the other hand, can reduce the impact of expectations, especially when the results depend on the evaluation of the researcher or the participant.
None of these elements makes the study perfect, but together they increase the confidence that the observed difference can be related to the intervention and not just to the passage of time, expectations, or other changes.
The studies of the eyelash serum containing the peptides discussed in this article were small and open-label.[1][2]
Their favorable results therefore constitute preliminary evidence regarding specific finished products.
They should not be treated as equivalent to a large, randomized, blinded, and appropriately controlled clinical trial.
At the same time, these limitations should not be presented as evidence of a complete lack of research on peptide eyelash products.
Such studies exist.
The most appropriate conclusion is this: the available evidence is preliminary and leaves several important questions unanswered.
The number of participants and missed visits should be clearly reported
The percentage results in small cosmetic studies can easily be misinterpreted.
The percentage increase in the average length of eyelashes means something different than the percentage of participants whose eyelashes became longer.
Similarly, the information that „90% participants experienced an improvement” is not the same as the statement that the average measured length increased by 10%.
A transparent study should therefore provide information on how many people started participating, how many completed the individual stages of the assessment, and how the missing observations were handled.
Small studies can also generate unstable percentage values.
If all the people in the very small group declare satisfaction, the statement „100% participants were satisfied” can sound much more convincing than the actual size of the sample justifies.
User satisfaction remains valuable information, but by itself it does not confirm the precise biological effect, does not identify the mechanism, and does not rule out rare adverse reactions.
Other active ingredients may interfere with interpretation
The multi-component product does not allow the peptide’s activity to be isolated.
Serum containing peptides, plant extracts, conditioning substances, and growth factor-related components constitutes a complex intervention.
If the appearance of the eyelashes improves after its application, the test can confirm that the improvement occurred during the use of the entire formulation.
However, it does not automatically determine which component was the cause of it.
A more informative study on a specific peptide would compare similar formulations, the main systematic difference between which would be the presence or absence of the peptide under study.
Existing small-scale studies can therefore be described reliably without attributing a causal relationship to individual components.
It is also not necessary to automatically assume a synergy.
If a multi-ingredient product produces a specific effect, this does not mean that its components mutually enhance their effects beyond the effects of each of them used separately.
Demonstrating synergy requires a research project that allows the comparison of individual components and their combinations.
Studies combined with treatments are not evidence of the regular use of serum
A 2020 publication described six women in whom a local preparation containing peptide extracts was used in combination with repeated microdermabrasion. [5]
It was a combined intervention.
Due to the very small group size, the lack of proper control, and the combination of the topical preparation with the treatment, it is not possible to reliably attribute the observed effects to conventional topical use of peptides.
The study also does not confirm the formation of new follicles just because more hair became visible in the imaging.
Its greatest value is methodological in nature.
It shows why, before generalizing the headline about „hair growth peptides” to ordinary cosmetic serums, it is necessary to carefully examine what the actual intervention looked like.
Evidence regarding prostaglandins should not be presented as evidence regarding peptides
Controlled studies of the prostaglandin analogue relate to this particular compound and the formulation in which it was used.
They do not confirm the effect of a peptide serum with a different composition and mechanism of action.
The same principle applies to safety.
Adverse effects observed with a product related to prostaglandins should not be automatically presented as peptide adverse effects.
In a prospective study from 2026 involving 19 women, the use of an eyelash serum containing a prostaglandin analogue was associated with changes in tear film stability, tear volume, and eye redness during a six-week observation period.[6]
The study was small and does not allow determining the frequency of such effects for all products.
However, it demonstrates an important principle: the effect of the product on the surface of the eye should be evaluated directly, and not inferred based on whether the eyelashes look better.
Cosmetic effectiveness and tolerance around the eye are two separate questions.
Current safety opinions require precise interpretation
In the final opinion adopted in February 2026, the EU Scientific Committee on Consumer Safety assessed three specific analogues of prostaglandins used in cosmetics intended for eyelash and eyebrow growth. The Committee concluded that, based on the available data, the substances cannot be considered safe for these cosmetic applications. Among the issues raised were strong pharmacological activity and insufficient data to rule out certain reproductive and developmental risks. [7]
The scope of this proposal is very important.
The opinion concerns specific prostaglandin analogues that are being evaluated.
It does not prove that all peptide serums are dangerous, nor does it apply automatically to every eyelash product.
Similarly, scientific opinions regarding safety should not be automatically presented as a universal legal ban without a separate examination of the applicable regulations and regulatory status.
The significance of this opinion for the evaluation of peptide serums for eyelashes is therefore primarily methodological: before attributing specific evidence or conclusions regarding safety to a product, its complete composition must be determined.
The general marketing category „eyelash serum” is not precise enough.
Eye tolerance should be evaluated separately
Cosmetic satisfaction is not a complete assessment of the safety of the eye area
The study participant may be satisfied with the appearance of the eyelashes, while experiencing irritation or changes in the surface of the eye.
Therefore, a comprehensive safety assessment may include reporting symptoms, an eye examination, and appropriate objective measurements, rather than limiting itself to stating that the product was „well tolerated”.
Similarly, the absence of reported adverse reactions in a small and short study does not mean that such reactions cannot occur.
Rare events may not occur in a group of just a few dozen people.
Some problems may also only become apparent after a longer period of exposure.
Two small studies of eyelash products containing peptides included a limited observation period in selected populations.[1][2]
Their favorable tolerance results should therefore remain related to the specific formulations and participants being studied.
They do not allow to state that every peptide serum is safe for every user or that it is safer than other categories of ingredients.
The application site and hygiene still matter
The serum intended for use along the lash line is not an eye drop.
Similarly, ordinary facial peptide serum does not automatically become suitable for use in rosacea just because it contains peptides.
The instructions for the finished product should specify the intended application site and the appropriate restrictions.
General guidelines for cosmetics used around the eyes emphasize the importance of using them according to their intended purpose, maintaining hygiene, not mixing products together, and discontinuing use if irritation occurs.[8]
The presence of peptides does not eliminate the usual risk of contamination of the applicator or the cosmetic product during use.
These are issues related to the finished product and the way it is used, not the peptide category itself.
Irritations, allergies, and unexplained hair loss should not be confused with effectiveness.
Baking is not evidence that the eyelash serum activated the biological growth mechanism.
Persistent redness, swelling, discomfort, or impaired vision should not be interpreted as a normal stage preceding the lengthening of the eyelashes.
Such symptoms require appropriate attention, and not increasing exposure to the product.
Similarly, a sudden or unexplained loss of eyelashes or eyebrow hair is not solely a question of the effectiveness of a cosmetic serum.
A clinical study conducted in healthy volunteers does not allow determining the cause of the unexplained hair loss in a particular person.
In such situations, appropriate clinical evaluation can provide more information than repeatedly changing cosmetics advertised as products for growing eyelashes or eyebrows.
What would stronger evidence look like for peptide serum for eyelashes?
A stronger clinical trial should start with an accurately characterized finished formulation.
The product should be compared with a corresponding control, the parallel cosmetic treatments and the way of care should be standardized, and repeatable measurements of parameters such as eyelash length, hair diameter, apparent density, and overall visibility should be used.
Where possible, researchers and evaluators of results should be appropriately blinded.
Eye tolerance should be evaluated separately, rather than assuming it based on satisfaction with the cosmetic effect.
The duration of the study should also correspond to the biological claim that is to be evaluated.
If the durability of the effect is important, observing it after the product has been used is particularly valuable.
Independent replication of the results by another research group would further increase the reliability of the evidence.
Until such data are obtained for a specific formulation, it is most justified to clearly distinguish between conditioning effects, changes in the apparent appearance, objectively measured hair parameters, and the demonstrated biological effects related to growth.
This allows for taking into account preliminary positive results without assigning them greater importance than they actually have.
Frequently asked questions about peptide products for eyelashes and eyebrows
Are longer-looking eyelashes evidence of new growth?
No. The apparent length of eyelashes can be influenced by many factors unrelated to the formation of new hair, including their curvature, darkness, coverage of the surface, separation, and reduction of breakage. The study of formulations containing peptides and glycosaminoglycans evaluated several eyelash characteristics separately, which shows why a general impression alone is not sufficient.[1] Controlled and standardized measurement is needed to confirm the actual change in length, whereas demonstrating the formation of new follicles would require even stronger evidence. Therefore, eyelashes that appear longer in themselves do not evidence the formation of new hair follicles.
Do all eyelash serums use the same type of ingredients?
No. Lash serums may contain peptides, conditioning agents, plant blends, prostaglandin analogs, or combinations of several groups of ingredients. Controlled studies of bimatoprost pertain to non-peptide interventions.[3] Their results cannot be automatically extrapolated to formulations containing only peptides. In evaluating the evidence, the full composition of the product under study provides significantly more information than the generic name „lash serum.”.
Does the product’s labeling as peptide-based confirm that it does not contain prostaglandin analogs?
No. The labeling of peptides on the front of the packaging does not reveal the entire composition of the product. Research on eyelash products includes various chemical groups of ingredients, including peptides and substances related to prostaglandins. [1][3] Therefore, before claiming that a product contains or does not contain a specific group of substances, it is necessary to check its actual composition. „Peptide serum” is a description of the product category, not a full declaration of ingredients.
Can conditioning make eyelashes look fuller?
Yes. Conditioning can change the appearance of existing hair. The formulation can reduce breakage, improve surface smoothness, change the shine or the way the lashes separate and make individual hairs appear more defined. In multicomponent studies, serum properties such as thickness, shine, curl or length were evaluated. [2] These may be real cosmetic effects, but they should not be automatically interpreted as evidence of increased hair follicles or the formation of new hair.
Does a larger number of visible lashes mean the formation of new follicles?
No. A higher number of visible hairs indicates that more hair was detected under certain measurement conditions, but does not confirm the formation of new anatomical follicles. Previously less visible hair may become easier to detect, and existing follicles may be in different stages of the natural hair cycle. Even studies measuring the number of hairs do not allow us to conclude that new follicles are being formed based on this parameter.[1]
Can an eyelash study confirm the growth of eyebrows?
Not directly. The eyelashes and eyebrows are located in different anatomical locations and require measurements specific to that area. In eyebrow studies, for example, the density and diameter of the hair can be assessed, whereas eyelash studies often involve length, number, angle, or visibility.[4] A positive result for eyelashes therefore does not automatically confirm brow growth.
Are there any direct studies of serum for eyelashes containing peptides?
Yes. In small open-label clinical studies, multi-component formulations containing peptides or peptide-related compounds have been evaluated and beneficial changes have been noted in several eyelash parameters. [1][2] These findings should not be ignored, but their limitations must be considered. Small studies without adequate controls do not allow for reliable isolation of the effect of individual components and do not provide a level of causal certainty comparable to a randomized controlled trial under appropriate conditions. Therefore, they should best be considered preliminary evidence regarding specific products.
Does the result after 12 weeks mean a lasting improvement?
No. The result measured after 12 weeks of continuous use shows what was observed at that point. It does not prove that the effect will remain after discontinuing use of the product. The studies of products containing peptides discussed mainly evaluated the results during continued use. [1][2] A claim of a lasting or permanent effect would require appropriate follow-up after discontinuing the product.
Can tattooing, eyelash lifting and other procedures affect the test results?
Yes. Tinting, dyeing, lifting, extension, and the method of care can affect the visible length, thickness, darkness, curvature, and separation of the eyelashes. Since many studies are based on measurements taken from photographs, these practices should be controlled or accurately documented.[1] Otherwise, part of the difference between the beginning and end of the study may result from another cosmetic intervention, rather than the serum being tested.
Does the open-label study allow to determine which component was responsible for the effect?
No. An open-label study may show that certain changes occurred during the use of a ready-made multi-ingredient product, but it does not automatically allow determining which component caused them. A study of serum containing multiple ingredients provides information primarily about the complete formulation. [2] Stronger evidence regarding a specific peptide would require a proper comparison of formulations differing primarily in the presence of the peptide under study.
Do studies combining microneedling with peptides confirm the effect of ordinary serum?
No. The combination of a topical preparation and microdermabrasion represents a different intervention than the simple application of a serum. In a very small study involving six people, peptide extracts combined with repeated microdermabrasion were used without a control to separate the effects of the two components. [5] Such results cannot be considered evidence of the action of the serum itself or a basis for performing procedures around the eyes without appropriate professional supervision.
Are the adverse effects of prostaglandin analogues serums automatically associated with the risk of peptides?
No. Safety data should remain associated with the ingredient and formulation that was actually studied. The 2026 study on tear film stability, tear volume, and eye redness included serum containing a prostaglandin analog rather than a purely peptide product.[6] Therefore, the results of this study should not be presented as peptide-related adverse effects. This does not mean that peptide products are automatically risk-free—it merely means that safety evidence must be attributed to the appropriate group of ingredients.
Does the absence of reported irritation mean universal safety for the eyes?
No. Small studies involving selected participants and a short observation period cannot rule out rare or delayed reactions. In available studies of peptide-containing preparations, favorable tolerability has been reported, but the results apply to specific formulations and the participants studied. [1][2] They do not confirm the safety of every peptide serum for every person.
Can facial peptide serum be used as a mascara serum?
Not only because it contains peptides. Products intended for the face and preparations designed for the eyelashes may differ in composition, method of application and tolerance assessment. Proof of good tolerance of the serum on other parts of the face does not mean that it is suitable for use around the edge of the eyelid or in contact with the surface of the eye. The intended use should be determined by the instructions for the specific finished product.
Does the burning mean that the serum stimulates eyelash growth?
No. Burning or irritation is not evidence of the activation of the hair growth mechanism. Clinical studies do not use discomfort as a marker of effectiveness. Claims of increased eyelash length or density should be supported by appropriate measurements, and not by sensations during application. Therefore, discomfort should not be interpreted as a necessary step in achieving a cosmetic effect.
Does the SCCS opinion from 2026 apply to every peptide eyelash serum?
No. The SCCS opinion concerned three specific prostaglandins used in cosmetics for eyelashes and eyebrows. [7] Its conclusions should not be extended to all products containing peptides. Similarly, a scientific opinion should not be automatically treated as a complete determination of the legal status of a product in each country. Proper interpretation begins with determining the specific ingredient, not the broad category name of the product.
What would increase the credibility of the claim of eyelash growth after the use of peptides?
The most convincing evidence would come from a controlled clinical trial that precisely characterizes the prepared formulation compared to a suitable comparator. The trial should standardize parallel cosmetics and skincare treatments, use repeatable measurements of length, density, diameter, or other previously defined parameters, apply appropriate blinding where possible, and separately assess tolerance to the ocular surface. However, post-product discontinuation observation would help determine the durability of the effect. The current small open-label studies do not yet answer all of these questions.[1][2]
Summary
Pectin-based products for eyelashes and eyebrows constitute a diverse group of cosmetic formulations, rather than a single standardized type of product that stimulates hair growth. Products labeled as peptide serums may contain different peptide sequences, concentrations, conditioning ingredients, plant extracts, growth factor-related substances, and additional active ingredients. Therefore, evidence regarding a single ready-made formulation should not be automatically applied to all products that use similar marketing descriptors.
The most important thing is to distinguish between conditioning existing hair, improving its visibility, increasing measured length or density, influencing the retention of hair, and demonstrating biological changes in the growth process.
These effects may be related to each other, but they are not equivalent.
Existing lashes can appear fuller thanks to better conditioning, a darker appearance, reduced breakage, or a change in curvature. A higher number of visible hairs does not confirm the formation of new follicles, and the increase in measured length alone does not indicate which component was responsible for the change.
Direct studies of eyelash formulations containing peptides do indeed exist. In small open-label studies, beneficial changes in several eyelash parameters were noted. [1][2] They constitute justified preliminary evidence regarding specific products, but they are limited by small sample sizes, multi-ingredient formulations, and a lack of comparisons that allow the isolation of the effect of individual peptides.
Evidence regarding prostaglandin analogues must remain separate from evidence regarding peptides. The results of controlled studies of bimatoprost or other products related to prostaglandins cannot be used to confirm the efficacy of cosmetics containing only peptides. Similarly, data regarding the safety of prostaglandin analogues should not be automatically attributed to peptides.
Studies combining topical preparations with treatments such as microdermabrasion also involve different interventions and should not be presented as evidence regarding the normal use of serums.
The most reliable interpretation therefore requires checking exactly which formulation was tested, whether the study concerned eyelashes or eyebrows, what parameters were measured, how long the participants were observed for, whether appropriate controls were used, and whether eye tolerance was assessed independently of the cosmetic effect.
Currently, studies on peptide products for eyelashes and eyebrows provide preliminary evidence regarding certain specific formulations. However, they do not confirm that all peptide serums lead to the formation of new follicles, provide lasting growth, or have the same effect.
Statements should remain consistent with the effect actually intended: conditioning should be described as conditioning, improvement in visibility as improvement in visibility, increase in measured length as a change in length, and claims of biological growth-promoting stimulation should require evidence capable of directly demonstrating such an effect.
Disclaimer
The article is purely educational and scientifically informative in nature. It discusses cosmetic ingredients, products for eyelashes and eyebrows, methods of clinical research, and the interpretation of claims regarding hair growth. It does not recommend a specific product or therapy, is not intended to diagnose the causes of eyelash or eyebrow loss, does not contain instructions for performing procedures around the eyes, and does not replace advice from a suitably qualified healthcare professional.
Evidence regarding a specific peptide, a prostaglandin analogue, cosmetic serum, brow product, or treatment should not be automatically generalized to other products or groups of ingredients. The results of laboratory studies, small open-label studies, uncontrolled observations, and controlled clinical trials should remain linked to specific formulations, populations, application sites, and the conditions in which they were obtained.
Cosmetics intended for use on the eyelash line are not automatically intended for direct contact with the surface of the eye. It should also not be assumed that regular facial peptide serum is suitable for use on eyelashes or eyelids just because it contains peptides. Persistent irritation, redness, swelling, visual disturbances, or unexplained loss of eyelashes or eyebrows should be properly evaluated and not interpreted as evidence of the cosmetic’s effect on hair growth.
References
- Fernandez-Gonzalez, P., Truchuelo-Díez, M. T., & Gómez-Sánchez, M. J. (2024). Open clinical trial evaluating the efficacy of a novel eyelash growth enhancer with peptides and glycosaminoglycans. Journal of Cosmetic Dermatology, 23(6), 2170–2180. https://doi.org/10.1111/jocd.16265
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