Hair porosity and pH: the key to better eyelash retention

Have you ever wondered why some clients’ lash extensions seem to hold up beautifully, while others experience quicker shedding?

Eyelash retention isn’t just about skill—it also has a lot to do with hair porosity and the pH of the products you’re using!

In this article, we’ll break down why understanding these two factors can seriously level up your lash extension game. For a deeper dive into common retention issues, check out our guide on why lash extensions don’t last.

 

What is hair porosity, and why should we care as lash artists?

Simply put, hair porosity is about how well hair absorbs and holds onto moisture.

When it comes to lashes, porosity levels influence how the lash adhesive interacts with natural lashes.

For glue selection, storage and troubleshooting, check out our full Lash Adhesive Guide.

Here’s the rundown:

High porosity lashes

Think of these lashes as super absorbent—they soak up moisture quickly but also lose it fast.

Because their cuticles are more open, they can absorb a bit too much lash adhesive, leading to weaker bonds over time.

Ideal porosity

When the cuticles are moderately open, they’re just the right balance—allowing enough adhesive in without compromising bond strength.

Perfect eyelash retention!

Low porosity lashes

These lashes are more resistant, with tight cuticles that don’t let moisture (or adhesive) in as easily.

They’re strong, but their low absorption can make it a little trickier for the adhesive to bond well.

How pH affects lash adhesion

You’ve probably heard of pH in skincare, but did you know it’s just as important in eyelash extensions?

pH is a measure of how acidic or alkaline a product is, on a scale from 0 to 14.

Natural lashes sit around 4.5 to 5.5, but lash cleansers and primers work best in the 5 to 7 range for optimal eyelash retention.

Here’s why:

• pH 5-7 (neutral to slightly alkaline): Products in this range help prep the lash by gently lifting the cuticle—enough to allow for better lash adhesive grip without causing damage. This range is ideal for eyelash retention.
  
• too alkaline (above 7): When pH levels are too high, the cuticles can open excessively, leading to dehydrated, brittle lashes that won’t hold extensions well.
  
• too acidic (below 5): A lower pH tightens the cuticles, creating a slick, smooth surface that makes it hard for lash adhesive to bond.

With all this in mind, selecting the right cleansers and a high-quality lash primer is key.

Lash-specific cleansers are usually formulated around the ideal 5-7 pH range to create that perfect bonding surface while keeping lashes in top shape. To enhance adhesive performance, consider using our Charisma Eyelash Extensions Glue Booster to optimize bonding, especially for challenging lash types.

Look for these kinds of products, and you’ll likely see a difference in retention right away!

EXPERT TIPS: How to apply this knowledge for better eyelash retention

1. Assess lash porosity: Highly porous lashes may need a gentler primer, while low-porosity lashes benefit from a bit more prep for bonding.
   
2. Pick pH-balanced products: Products in the 5-7 pH range are your best bet to achieve lasting, strong eyelash extensions.
   
3. Client education: Let clients know about the importance of lash-friendly cleansers (usually around pH 5-7) so they can maintain their lash extensions at home without weakening the bond.

Knowing how hair porosity and pH work together can give lash artists an edge in achieving longer eyelash retention, healthier lashes, and happier clients.

Happy lashing! 🌟

About the author

Written by a multi-award-winning lash artist, international competition judge, and trusted educator at The Lash Box Shop, with years of hands-on experience helping professional lash artists improve their eyelash extension technique, speed, and confidence behind the tweezers. Passionate about elevating standards in the lash industry, she now shares expert insights to help lash technicians grow stronger, more profitable businesses.