Lash Serums: What's Really Going On in That Tiny Tube?

Longer, fuller-looking lashes sound wonderful—but lash serums are not all created equal.

Some products simply condition the lashes and help reduce breakage. Others contain ingredients that can alter the lash-growth cycle and may produce more dramatic results, along with a greater chance of side effects.

I'm here to help you choose your serum with your eyes open—literally and figuratively.

There are two main types of lash serums:

Prostaglandin-Based Serums

• • These formulas have evidence that they produce noticeable increases in lash length, darkness, and thickness by affecting the natural growth cycle.

  • They also have potential side effects such as eye irritation (blood shot eyes), eyelid discoloration, loss of fat in the eye socket causing sunken, hollow look, darkened iris, or other side effects.

Non-Prostaglandin Serums

• • These typically contain peptides, growth factors, vitamins, amino acids, oils, or botanical extracts.

  • They are generally marketed to condition, strengthen, and support healthier-looking lashes. Results may be more subtle, and research varies widely by ingredient.

An Esthetician’s Perspective

Prostaglandin-Based Serums

These are very effective. You may visit a physician for a product containing Bimatoprost or purchase an over-the-counter product (the most common ingredient is Isopropyl Coprostenante). Products include Grande Lash, Babe Original Essential Eyelash Serum, Rodan + Fields Lash Boost, Rapid Lash, and Borboleta. 

I only recommend these products for clients who are well informed and aware of the potential side effects (see Getting Nerdy with Lashes). Most side effects will resolve in 3-12 months, however the side effect of a darkened iris may be permanent.

Non-Prostaglandin Serums

For clients who want healthier-looking lashes without prostaglandin-related ingredients, I am most interested in thoughtfully formulated products containing:

• Peptides

• Panthenol

• Conditioning ingredients

• Growth factors from reputable manufacturers

• Clearly disclosed ingredient lists

I am also interested in Jarilla-Coffea extract for brow products, although more research is needed.

Castor oil may help condition the hair, but I do not consider it a well-supported lash-growth ingredient.

Application Tips

• Apply only the recommended amount.

• Keep the product off the waterline and out of the eye.

• Use a thin application along the upper lash line unless directed otherwise.

• Do not assume more product will create faster results.

• Speak with an eye-care professional if you have an eye condition, use glaucoma medication, have had eye surgery, or develop vision changes.

• Ask a medical provider before using a lash serum during pregnancy or while nursing.

A Note About Safety

• Over-the-counter does not automatically mean risk-free.

• Cosmetic lash serums are not required to prove that they are effective before being sold, and some studies have found products containing prostaglandin-related ingredients that were not clearly listed on the label. 

• Always read the full ingredient list, apply the product carefully

• Stop using it if you experience ongoing redness, swelling, itching, pain, vision changes, darkening around the eyes, or noticeable hollowing near the eyelids. This may be a sign of an undisclosed ingredient.

Final Thoughts

A serum that conditions the lashes is very different from a product that alters the growth cycle.

Neither option is automatically right or wrong. The important thing is knowing what you are using, understanding what kind of result is realistic, and recognizing possible side effects.

Healthy lashes do not always require the most dramatic formula. Sometimes the best result is less breakage, better flexibility, and lashes that look fuller because they are being treated kindly.

This information is for general education and is not medical advice. An aesthetician can help you review cosmetic ingredients and support the appearance of your lashes and brows. Eye conditions, unexpected hair loss, medication concerns, or reactions around the eyes should be evaluated by an appropriate medical or eye-care provider.