The Ordinary sells one of the most popular lash and brow serums, and the brand claims that this product can give lashes and eyebrows “a thicker, fuller and healthier look.” 

But can lash and brow serums actually increase hair thickness? Does this product contain any unhealthy ingredients? What was our Product Tester's experience trying it for a month? And is it better or worse than popular lash serums like Babe Lash Serum?

In this article we’ll answer all of these questions and more, as we analyze the ingredients in The Ordinary Multi-Peptide Lash and Brow Serum to give our take on whether or not it's product is likely to support lash growth, and whether or not it's healthy.

We'll also share our Product Tester's honest experience trying it for a month (including before-and-after images), and compare this lash serum to other popular lash serums to pick our winners (and losers).

Key takeaways:

• Should stimulate growth & support hair thickness
• Contains inactive ingredients we consider unhealthy
• We do not currently recommend Multi-Peptide Lash and Brow Serum

Ingredient Analysis

The ingredients in The Ordinary Multi-Peptide Lash and Brow Serum are shown below:

The Ordinary's serum contains a number of peptides from which it gets its name.

Myristoyl pentapeptide-17 was shown in a clinical trial published in the Journal of Clinical and Aesthetic Dermatology to have the potential to stimulate eyelash growth.

Trifolium pratense flower extract was shown in a 2020 medical review to potentially mitigate hair loss.

Arginine was shown to protect hair from damage in a 2004 clinical trial.

Camellia sinensis leaf extract was shown to “stimulate hair roots and extend the hair growth phase” when applied topically, as documented in a meta-study published in the Molecules journal.

While this serum contains a number of research-backed ingredients, it also contains several questionable inactive ingredients.

Phenoxyethanol is a synthetic preservative that was shown to be toxic to human cells in a clinical trial, as we documented in our Better Not Younger reviews article on another cosmetics brand that uses this ingredient.

Chlorphenesin is another preservative that’s even harsher in our opinion, and has been shown in clinical research to be toxic to human cells, to irritate the eye and to be toxic to cells in the eye.

This formulation contains four other preservatives: sodium metabisulfite, sodium benzoate, benzoic acid and ethylhexylglycerin. 

Preservatives may be necessary in some cosmetic formulations to ensure the quality of the ingredients, but we have never reviewed a lash or brow product containing six different preservatives, and would be curious to hear from the brand about why so many are needed.

Overall, we consider this serum likely to increase lash and brow thickness and to improve lash quality generally due to its research-backed active ingredients.

We do not currently recommend this product due to the inactive ingredients discussed above.

We Tested Lash and Brow Serum

One of our Product Testers named Amy Lau tested The Ordinary Multi-Peptide Lash and Brow Serum for a month.

Here's her before image:

The packaging is straightforward.

The applicator deserves mention because it’s easier to control than most others I’ve tried — flexible but slightly firm, which made it simple to apply along both lash lines and on eyebrows. No issues with opening, dispensing, or applying.

This product is odorless. There was no scent I could detect.

I started with sparse lashes and brows. After roughly 3–4 weeks of use, even without full consistency, I noticed:

• Lashes appeared somewhat fuller and more visible
  

• Brows looked slightly thicker and easier to shape
  

• Mascara applied more easily because the lash volume

   

   

The Ordinary lash serum provided measurable improvement, but not as dramatic as the two most expensive brands I’ve tried previously.

I have sensitive skin, so the only side effect I experienced was experienced mild irritation — a bit of flakiness on the eyelids visible under magnification.

I adjusted to using it every other day, which reduced the irritation while maintaining results.

This product didn’t eliminate the need for makeup for me, but it did make a noticeable aesthetic difference.

Here's the after image:

Overall, I rate this product 8 out of 10, with the only points deduction due to the mild side effect.

But I have more sensitive skin than most, and the sensation went away after 10 seconds. It does its job to achieve more thickness and length, and it’s a great value.

The Ordinary vs. Popular Lash Serums

Here's how The Ordinary Multi-Peptide Lash and Brow Serum compares to other popular lash serums in terms of potential effectiveness and healthiness, in our opinion:

Babe Lash Serum

Among other research-backed active ingredients, contains grape seed extract which is clinically shown to support hair growth.

However, it also contains an active ingredient which was the subject of a lawsuit over alleged adverse reactions, making The Ordinary's serum the safer choice.

Winner: The Ordinary Multi-Peptide Lash and Brow Serum

Rodan + Fields Lash Boost

Rodan and Fields Lash Boost contains a similarly potent formulation to The Ordinary, and we consider both products likely to be effective.

Rodan + Fields' serum contains fewer inactive ingredients we consider unhealthy, so it gets the (slight) edge from a healthiness perspective.

Winner: Rodan + Fields Lash Boost

Thrive Causemetics Liquid Lash Extensions

Contains no active ingredients we consider likely to be effective for improving the thickness and appearance of lashes.

Both products contain unhealthy inactive ingredients, so we give The Ordinary the edge from a potential efficacy standpoint.

Winner: The Ordinary Multi-Peptide Lash and Brow Serum

Our Clean Lash Boost Pick

Organic Eyelash and Eyebrow Growth Serum by Live Fraiche is our top lash serum pick.

This product has one single ingredient: organic castor oil, and is entirely free of preservatives.

A medical review published in the Journal of Drugs in Dermatology described castor oil as having the potential to improve hair quality.

While we don't believe the clinical evidence on castor oil for hair growth is particularly convincing, we definitely consider this to be a healthier option than commercial eyelash and eyebrow serums, and may be worth trying.

Multi-Peptide Serum Pros and Cons

Pros:

• May support lash growth
• May mitigate lash hair loss
• May improve lash quality and appearance
• Affordable
• Our Product Tester noticed substantial aesthetic effects

Cons:

• Contains six preservatives
• Doesn't appear to be clinically tested
• Our Product Tester experienced minor irritation
• Some competitors are healthier

Conclusion

We believe that The Ordinary Multi-Peptide Lash and Brow Serum is likely to be effective for improving eyelash and eyebrow thickness, as well as improving hair quality generally.

The serum contains several ingredients (like peptides) shown in clinical studies to promote hair growth and prevent hair loss, and is priced quite affordably.

We do not currently recommend this product due to the inclusion of six different preservatives. 

We would recommend that consumers be especially cautious of using cosmetics with questionable ingredients around the eyes, which is one of the most sensitive areas of the body and prone to irritation and damage.

Unfortunately, for whatever reason, the lash serum industry seems to produce products with more questionable inactive ingredients than the average cosmetic product.

We hope this changes in the future, and this seems counterintuitive because the eyes are more sensitive than skin.

Our Product Tester tried this serum for a month, and she experienced great aesthetic effects, but also experienced mild side effects.

We consider The Ordinary Multi-Peptide Lash and Brow Serum to be a better formulation than Thrive Causemetics Liquid Lash Extensions, but a less healthy option than Babe Lash Serum and Rodan + Fields Lash Boost.