There’s no shortage of ways to get long, thick, gorgeous eyelashes. Plenty of people consider mascara a daily must-have in their makeup bag, while others grab false lashes for even more of an impact. Semi-permanent lash upgrades, like lash lifts and eyelash extensions, make a great option for people who want to reduce their daily lash upkeep—but these services can be costly and time-consuming. And then there are lash serums: formulas that promise longer and fuller natural eyelashes, easy.

Most eyelash serums are easy to apply, requiring just a few swipes of a wand per day. But do these formulas really work, and is there anything you should know before you add one to your beauty regimen? Let’s dive right in.

What is eyelash serum?

Eyelash serums are a beauty product that reportedly help you grow thicker, fuller, darker eyelashes. They typically fall into two categories: prescription strength products from a medical provider and over-the-counter serums bought at a cosmetics store.

Latisse is currently the only Food and Drug Administration (FDA) approved eyelash serum available. It’s approved to treat hypotrichosis, the medical term for thin, sparse lashes.¹ The active ingredient in Latisse is a hormone-like substance (prostaglandin) called bimatoprost, which stimulates lash hair growth.²

The FDA doesn’t approve drugstore lash serums, so they can’t make concrete claims that their products cause eyelashes to grow. However, there are over-the-counter options that claim to condition and strengthen lashes, enhancing their appearance. It’s important to know that some over-the-counter options contain a synthetic form of prostaglandin similar to bimatoprost and may improve eyelash growth, but the actual effects are largely unknown and unproven.³

Lash growth serum vs. lash conditioner

Lash growth serums and lash conditioners are similar products that are often confused. Lash serums are intended to help you grow new healthy lashes, while lash conditioners are intended to help moisturize your existing lashes.

That said, both may help you achieve the appearance of denser, healthier-looking lashes. You can even use both of these products (but not at the same time) as part of your eye care routine. The lash serum may help you to grow new, thicker lashes, while the eyelash conditioner may help keep your new ones moisturized.

How do lash serums work?

All of the hairs on your body, including your eyelashes, go through certain stages in their life cycle. The stages in the lash cycle are the anagen phase (growth), the catagen phase (transition), and the telogen phase (rest).⁴ 

The active ingredient in Latisse is believed to work by stimulating the hair follicles and prolonging the anagen or active growth phase. This means they spend more time growing and, in turn, become longer and thicker. Since not all of your eyelashes are in the same phase of the lash growth cycle at the same time, it takes a few weeks to begin to notice the effects of the lash serum.⁵

Over-the-counter eyelash serums claim to work by strengthening the hair shaft with “proprietary peptides,” natural extracts, vitamins, and prostaglandin analogs. Although the over-the-counter products have not been evaluated for their efficacy and safety, the products that contain prostaglandins may help improve eyelash growth.⁶ 

How to apply lash serum

To apply your lash serum, it’s best to follow the directions on the package or those provided by your healthcare provider. But as a general guide, to apply lash serum, you should:

1. Remove your eye makeup and wash your face. We recommend our Micellar Makeup Remover to remove dirt and makeup without irritating your skin.

2. If applicable, remove your contact lenses.

3. Prepare the applicator according to the instructions. Some serums must be applied to a brush, while others come in a tube like mascara.

4. Apply the serum to the skin at the base of your upper lashes.

5. Do not use the serum on lower lids, as this can cause irritation.

6. Blot any excess liquid with a tissue.

7. Let the serum dry for at least five minutes before applying makeup.

How often should you use eyelash serum? Most eyelash growth serums say to use them daily, and as a general rule of thumb, you should follow the directions on the package. It’s recommended that you keep using your lash serum regularly to maintain your new growth. When you stop using eyelash serums, your lashes will likely return to their pre-serum state as the treated eyelashes complete their hair growth cycle and fall out.

Using lash serums with your skincare routine

It’s easy to incorporate lash growth serum into your skincare routine. It can fit into your morning routine before applying makeup (just ensure the serum is dried first). Or, if you prefer, you could also apply your lash serum at night, after removing your makeup.

How long does lash serum take to work? You may begin to notice the effects of Latisse as soon as four weeks after you add it to your routine. Full results take up to 16 weeks. If you use an over-the-counter serum, the time will likely vary, but like Latisse, you might start seeing stronger lashes at around the four week mark.

The first change people usually notice is that their lashes appear longer. After continued use, they may also appear to be thicker and darker.

Lash serums may help you get thicker, fuller lashes without mascara or lash extensions. However, they aren’t all created equally, and it’s important to talk to your medical provider about their risks and benefits.

Here at Curology, we’re committed to providing accessible skincare to all. If you have skincare concerns, our licensed dermatology providers can help.

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Just take our quick skin quiz and snap a few selfies for a professional evaluation. If Curology is right for you, we’ll send you a 30-day supply of your personalized prescription formula plus any other recommended products. Sign up for a trial today!*

P.S. We did homework so you don’t have to:

1. Patel, B.C., and Joos, Z.P. Diseases of the Eyelashes. StatPearls. (2022, December 19).

2. Huang, A.S. and Meyer, J.J. Bimatoprost Ophthalmic Solution. StatPearls. (2022, November 14). 

3. Jones, D. Enhanced Eyelashes: Prescription and Over-the-Counter Options. Aesthetic Plast Surg. (2010, August 21).

4. Hoover, E., et al. Physiology, Hair. StatPearls. (2022, July 25).

5. Law, S.K. Bimatoprost in the treatment of eyelash hypotrichosis. Clin Ophthalmol. (2010, April 26). 

6. Jones, D. Enhanced Eyelashes: Prescription and Over-the-Counter Options. Aesthetic Plast Surg. Ibid.

7. US Food & Drug Administration. Cosmetics Q&A: Why are cosmetics not FDA-approved?. (2022, February 25). 

8. Chanasumon, N., et al. Therapeutic potential of bimatoprost for the treatment of eyebrow hypotrichosis. Drug Design, Development and Therapy. (2018, February 22).

Laura Phelan is a board-certified Family Nurse Practitioner at Curology. She earned her Masters of Science in Nursing at Benedictine University and went on to get her post-master’s certificate as a Family Nurse Practitioner at the University of Cincinnati.

*Cancel anytime. Subject to consultation. Results may vary. 

Written by

Curology Team

Medically reviewed by

Laura Phelan, NP-C