How Long Does a Lash Serum Take To Work? Brands Compared!

You are thinking about using an eyelash growth serum to enhance your lashes and make them longer, but naturally, you are wondering how long it will take for the serum to work.
Eyelash serums take around 7 to 14 days to start working. For most lash serums, 60 to 90 days to are required to notice a significant change in eyelash length, fullness, and luster.
I have delved into in-depth research and found 3 sources of information to find out how long does a lash serum take to work:
- What lash serum brands say
- What clinical trials say
- What people using lash serums say
In this article, I will share with you this information so that you can make an informed decision before using one.
So, keep on scrolling to find out all about it!
Disclaimer: Although I have been doing lash enhancement treatments for years, I am not a doctor. All content and information in this post are for informational and educational purposes only and do not constitute medical advice. Always seek the advice of your own Medical Provider regarding any questions or concerns you have about your specific health before implementing any recommendations or suggestions from our Website.
What Lash Serum Brands Say
Each eyelash growth serum manufacturer report slightly different results on their website for the time it takes their serum to work.
Why is that?
Mostly because not all eyelash serums are made the same. They all have different ingredients that can influence the amount of time it takes before having a noticeable difference.
Also, let’s be honest, there are probably some marketing strategies at play.
To make things easier, I decided to compile a list of some of the most popular lash serum brands and how long they say their serum takes to work.
There are dozens if not hundreds of eyelash serums on the market today. So, I only chose to include some of the most popular and talked about brands.
As you can see, the results differ quite a bit. Some brands claim that it only takes one to two weeks while others report that it could take up to eight weeks.
The thing is, all these brands are likely telling the truth about their product. But, it’s important to understand that not all serums are made the same and that could be why there’s such a big difference.
For example, some serums have potent active ingredients that will produce results faster. However, these serums could also come with some side effects like darkening of the skin around the eyes, irritation, redness, and dryness.
On the other hand, serums with more gentle ingredients might take longer to work but be less likely to cause any side effects.
It’s important that you read the ingredient list before purchasing any lash serum so that you can make an informed decision.
Pro Tip: Check out my definitive guide about lash serums where I go in detail about the ingredients they contain.
What Clinical Trials Say
Brands can make claims, but at the end of the day, what really matters is if there’s any scientific evidence to back up those claims.
Unfortunately, when it comes to lash growth serums, there are not a lot of high-quality studies. I did manage to find two clinical trials that looked at the efficacy of lash serums:
- Latisse clinical trials.
- MS Clinical Research clinical trials.
Let’s look at each one in detail.

Latisse Clinical Trials
The first clinical trial I want to talk about is the one done by Allergan, the makers of Latisse.
Latisse is the only FDA-approved lash serum on the market today. This product is marketed as a treatment for hypotrichosis, which is the loss of eyelashes.
The active ingredient that can be found in Latisse is called “Bimatoprost” which is part of the prostaglandin class of drugs.
You can find the clinical review data from the FDA’s website right here.1
Here’s what they did:
- Evaluate the efficacy of bimatoprost 0.03% in promoting the growth of eyelashes.
- Subjects were instructed to apply the solution once per day on the upper eyelid.
- The study consisted of 8 visits over the course of 4 months with one post-treatment follow-up at month 5.
- The lash growth was accessed using the GEA scale (1=none or minimal eyelash prominence; 2=moderate eyelash prominence; 3=marked eyelash prominence; 4=very marked eyelash prominence).
Results:
- After 16 weeks, 78% of subjects in the bimatoprost 0.03% group had at least GEA 1-Grade increase compared to 18% in the vehicle group.
- After 20 weeks, 79% of subjects in the bimatoprost 0.03% group had at least GEA 1-Grade increase compared to 21% in the vehicle group.
- After 16 weeks, 32.8% of subjects in the bimatoprost 0.03% group had at least GEA 2-Grade increase compared to 1.4% in the vehicle group.
- After 20 weeks, 37.4% of subjects in the bimatoprost 0.03% group had at least GEA 2-Grade increase compared to 3.2% in the vehicle group.
So what can we conclude from these results?
The study found that the lash growth was significantly greater in the bimatoprost 0.03% group compared to the vehicle group.
Having said that, there were also adverse events (side effects) reported in the study. The most common side effects were erythema (redness), pruritus (itching), and skin hyperpigmentation (darkening).
It is important to note that Latisse is a prescription medication and should only be used under the supervision of a healthcare professional.
If you want to try a prostaglandin analog lash serum a try, I highly encourage you to read this comprehensive report.
Wait, Latisse is not the only one?
Indeed. Although Latisse is the only FDA-approved eyelash growth serum using a prostaglandin analog active ingredient (Bimatoprost 0.03%), there are other products on the market using prostaglandin analog ingredients!
And these growth serums are not FDA-approved which means less data for consumers to make a wise decision.
But that’s for another time… I’ll probably write an article about it at some point.
MS Clinical Research Clinical Trials
The next clinical trial worth discussing was done by MS Clinical Research.
You can find the study and results here.2
Here’s what they did:
- Subjects were 30 women, aged 18-45, hoping for better and fuller eyelashes.
- Each participant was asked to apply the serum at the margins of both eyelids evenly and in the same way to eliminate any room for error.
- Participants were instructed to apply the serum once every night for 90 days.
- Participants revisited the center for observations by dermatologists after 30, 60, and 90 days.
Results:
- Following 30 days of utilizing a polygrowth factor serum, subjects experienced the following improvements: lash length increased by 10.52%, volume improved by 9.3%, and thickness improved by 35%.
What People Using Lash Serums Say
Testimonials from real people are normally more valuable than anything else. It gives you a better sense of what to expect and how other people reacted to the serums.
That’s why I like Youtube.
There are tons of videos of people trying and reviewing different lash serums. So, I went ahead and compiled the 3 most popular ones I could find.
Women Try Eyelash Growth Serum For A Month
In this video, several women try 2 eyelash growth serums for 30 days and document their journey.
All of them have different lashes to begin with but they all end up with pretty amazing results.
What I love about this video is that they were instructed to apply two different serums, one on each eye! That way, they can easily compare which one works best.
Check it out!
Grandelash Review | 3-Month Results
Here, on youtube, Monica Esparza shares with us her results after using the Grande Lash MD Lash Enhancing Serum for 3 months.
Spoiler alert: she loved it!
The Truth About Lash Serum and Growing Long Lashes
Lainey Marie shares with us her amazing results using the Maxey Lash serum. She started noticing results after 4 weeks.
Make sure to watch this great video!
How Does an Eyelash Growth Serum Work in the First Place?
So far, we’ve discussed how long they take to work, but not how they actually work. Let’s briefly go over the science behind these lash serums so that you understand what’s going on.
In essence, these serums work by extending the growth phase of your eyelashes (anagen phase) and shortening the resting phase (telogen phase).
This allows your lashes to grow longer, thicker and fuller because they’re not falling out as often.
The lash growth cycle has three stages: the anagen (growth) phase, the catagen (degradation) phase, and the telogen (resting) phase. Each lash follicle goes through these phases independently of other lash follicles.
Anagen Phase
The anagen phase is when lashes are actively growing. This phase can last anywhere from 30 to 90 days. During this time, the follicle produces keratin, giving the lashes strength and flexibility.
Catagen
The catagen phase is a brief transitional period in which lash growth stops as the follicle shrinks.
Telogen
The telogen phase is the final stage of the lash growth cycle, which takes place once the follicle has fully grown. This phase lasts from 4 to 9 months. Here, the lash simply rests in the follicle. At the end of the telogen phase, the lash falls out, and a new one begins to grow in its place.
FAQ
Which Eyelash Serum Works the Fastest?
Latisse is the lash growth serum that works the fastest since it’s the only one that’s clinically proven to work. It is the only FDA-approved lash serum on the market. In a clinical study, 78% of participants saw significant lash growth after just 16 weeks.
How Long Does It Take To See Results With Lash Serum?
It can take anywhere from 7 to 14 days to start seeing results from an eyelash growth serum. Most manufacturers recommend waiting at least 60 days before making an assessment of the results.
How Long Should You Use Lash Serum?
Most lash serums should be used daily for 4 to 8 weeks for the best results. After that, you can continue using the serum 3 to 4 times a week to maintain your results.
The Bottom Line
To sum it up, how long it takes your lash serum to work depends on a few things.
- First, it depends on the ingredients in the serum.
- Second, it depends on how often you use the serum.
- And third, it depends on your own individual Lash Cycle.
On average, it takes about 4 weeks of daily use to see full results from a lash serum. However, you may start to see some lengthening and thickening of your lashes after just 2 weeks of daily use.
If you’re using a Lash Serum with active ingredients like biotin or keratin, you may see results even faster. Just be consistent and avoid applying too much lash serum in desperation for quicker results.
Pro Tip: Check out this article if you’re curious to know if lash serums do ACTUALLY work.
– Asako
References
- FDA (2008). Clinical Review Latisse (bimatoprost ophthalmic solution 0.03%). Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/nda/2008/022369s000_MedR.pdf [Accessed 19th June 2022].
- Mukta Sachdev, Keerthi Velugotla, Sapna Revanker, and Geetha Somasekhar. (2020). An Open-label, Single-center, Safety and Efficacy Study of Eyelash Polygrowth Factor Serum. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7158911/ [Accessed 19th June 2022].
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