Let me guess – you’ve been rummaging around in one of your make-up bags and come across an old lash serum. Win! You’re going to have fluttery and full lashes in no time.
But wait – it’s already been opened. And like any other skincare or beauty product, you know that lash serum probably has an expiry date.
So, how long does lash serum last?
In general, lash serum can last for up to 4-6 months once opened. If your lash serum is unopened, it should last for up to two years – but bear in mind that most lash serums are designed to be used for 3 months at a time. To ensure great results, I’d recommend opening it before the 2 years are up.
What’s great about lash serum is that most brands will give you enough product to last for a full 3 months of application. This means that you generally won’t end up wasting any product if you apply your serum daily, or as instructed by the manufacturer.
But how can you ensure that your lash serum lasts for the full 3 months of application, and how long do homemade lash serums last?
Let’s dive in!
How Can I Make My Lash Serum Last Longer?
While 4-6 months might seem like a short shelf life for a beauty product, lash serums are designed to be used for around 3-4 months at a time. This allows the lash serum enough time to prolong your lashes’ anagen phase, resulting in fuller lashes that are both longer, conditioned, and generally healthier.

Here’s how you can prolong the life of your lash serum to ensure an effective formula and visible results:
#1 Keep Applications Consistent
With a lash serum, you’ve typically only got around 4-6 months worth of use – this means you need to be consistent with your applications if you want to get your money’s worth. Skipping days, or going weeks at a time without using your serum can mean that it ends up expiring before the 3 month use period is up.
Not only does this mean you’ll have wasted both your money and your lash serum, but it also means that your results aren’t going to be as good as they could be. Consistent, daily application is key.
#2 Store Your Lash Serum in a Cool & Dry Place
Like your other beauty and skincare products, lash serum is best stored in a cool, dry place away from sunlight. While your lash serum bottle might look pretty on your dressing table, prolonged contact with sunlight can end up damaging the formula.
This is true for all your beauty products: UV rays can literally break down the emulsifiers in cream, oil, and lotion formulas, impacting the efficiency of the product.1 Storing your trusty lash serum in a make-up bag or in your bathroom cabinet is the best way to ensure that it remains functional.
#3 Don’t Overuse Your Serum
Another way to make your lash serum last longer is by ensuring you only follow the recommended application. Most lash serums are designed to be applied once a day, preferably before bedtime as part of your nighttime skincare routine. There’s no use in applying your serum twice a day unless the manufacturer recommends doing so.
In fact, applying your lash serum more than once a day can actually increase your chances of developing side effects, especially if you’re using a lash serum that contains prostaglandins. (Prostaglandins are chemical compounds used in certain eye medications and certain lash serums, and can cause orbital fat loss, discoloration, and irritation.)
You also need to be careful when applying your lash serum – using too much product will both irritate your eyes and also mean that your lash serum might not last for its full 3 months. If you do use too much by mistake, simply wipe off the excess with a cotton swab and be more precise with your next application.
How Long Do Homemade Lash Serums Last?
Now, what about homemade lash serums? Personally, I prefer a homemade lash serum – they’re safer for the eyes, they’re more affordable, and they can last much longer than your typical shop-bought serum.
So, how long do homemade lash serums last? To keep things simple, I’ve made a list below of all the various natural ingredients you can use for homemade lash serums, and how long they can last once they’ve been opened.
Coconut Oil
Using coconut oil is a popular homemade trick used to condition and strengthen the lashes. Once opened, a refined coconut oil should last for around 18 months, while a virgin coconut oil can last for up to five years. Although do make sure that your coconut oil (and any other natural ingredient) isn’t contaminated with other products. Don’t double dip – use an empty serum dispenser to keep things hygienic.
Castor Oil
Castor oil is another popular DIY hack for your lashes – and it’s also incredibly durable! Depending on the quality of the castor oil, it can last between 1 and 5 years when correctly stored.
Vitamin E
Vitamin E is great for your skin and hair, making it great for strengthening the lashes and preventing breakage. Generally, Vitamin E can last for up to 36 months once opened – do note that this applies to 100% pure Vitamin E oil, with nothing extra added.
Vaseline
The most durable of all the natural lash-enhancing ingredients, Vaseline can last for up to ten years (yes, really.) This is because there are no actives in Vaseline – it’s mostly used to hydrate and strengthen.
Essential Oils
Lavender and other essential oils used in homemade lash serums will typically last for up to two years. For best results, use organic essential oils from a trusted manufacturer.
As I mentioned above, always store any DIY lash serums in a clean applicator, and don’t use any contaminated products. There’s no point in having beautiful fluttery lashes if you’re going to give yourself an unpleasant eye infection!
The Bottom Line
For most store-bought lash serums, you can expect them to last around 4-6 months before you’ll need to buy a replacement. Homemade lash serums made using natural ingredients will tend to last longer, although you may not notice as dramatic an increase in the length or volume of your lashes.
To help your lash serum last longer, store it in a dry place, make sure that you remain consistent with daily use, and only follow the manufacturer’s recommendations for application.
Stay beautiful!
– Asako
References
- Niree Noel (2017). How the Sun Damages Beauty Products and Treatments. Retrieved from: https://www.allure.com/story/sun-damage-on-beauty-products-and-treatments (Accessed 22 September 2022)