What Does Lash Serum Do & How Do You Apply It?

best eyelash serum

Long, full lashes have the power to make eyes appear wider, brighter and more lifted. When it comes to achieving those voluminous lashes however, falsies and mascara aren’t the only options. Eyelash serum can help to enhance the appearance of your natural set – no makeup necessary.  

If you’re new to eyelash serum, keep reading. We explain how lash serum works, how to apply it, and where to find the best one. 

What is lash serum and what does it do? 

A lash serum is a serum thats applied to the lashes daily to help them appear thicker and fuller by supporting them through their three stages of growth. 

1. The Anagen or “growth” phase 

During this phase, lashes are actively growing. 35-40% of the upper lashes and 15% of lower lashes will be in the growth phase at one time to prevent all lashes from falling out at once. 

A lash serum can help to support lashes during the Anagen phase.   

2. The Catagen or “transition” phase 

In this phase, the hair follicle shrinks and the lash stops growing. If an eyelash is pulled out at this time, that follicle will stay empty until the Catagen and Telogen phases are complete, and the Anagen phase can begin again.  

Eyelash serums can help to keep lashes looking strong and healthy through the Catagen phase and transitioning into the Telogen phaseLash serums can create a fuller-looking lash line. 

3The Telogen or “resting” phase 

This phase begins when an eyelash is ready to fall out. It can take up to 100 days for a new lash to grow after the old one sheds. Approximately 50% of eyelashes will be in this phase at one time. 

Our best eyelash serum: No7 Lash Impact Serum 

With a unique blend of ingredients, No7 Lash Impact Serum makes lashes look visibly fuller, thicker and darker in just 8 weeks.  

  • Keratin (the protein in hair responsible for its strength, shape and structure), amino acids (the building blocks of this protein) and Vitamin B5 help to support the hair follicle for visibly thicker-looking lashes 
  • Antioxidants and Vitamins E and C help to protect from environmental stressors 
  • Conditioning and hydrating agents are combined with glycerin and hyaluronic acid to keep the hair moisturized and create a fuller looking lash fan 

How to apply eyelash serum 

Before applying eyelash serum, gently cleanse the eye area to remove makeup and dirt. Wait for the skin to dry, then glide the applicator along the upper lash line to apply a thin layer of serum onto the skin. Repeat on the lower lash line.  

Eyelash serum should be applied every evening for at least 8 weeks.  

Can you use eyelash serum with mascara? 

Pairing eyelash serum with mascara will further accentuate your lashes. Apply the serum to the lash line, allow to dry fully, then apply mascara to the lashes 

  • For longer-looking lashes: No7 Lash Extender Mascara is enriched with volumizing spheres to make lashes look longer, with no clumps or flakiness.
  • For fuller-looking lashes: No7 Intense Volume Mascara separates and defines for more voluminous-looking lashes.
  • For fuller and longer-looking lashes: No7 Full 360 Ultra Mascara coats lashes from root to tip to add volume, length and curl for a dramatic false lash effect.  

Can you use eyelash serum on eyebrows? 

No7 eyelash serum can also be used on the eyebrows. Using the applicator, apply a thin line of serum down the center of the brow, from the top to the tip of the arch. In sparse areas, apply in thin strokes as if filling in the brow with a pencil. 

Brows will appear thicker, fuller and darker in 8 weeks. 

What happens when you stop using lash serum? 

A lash growth serum can take up to 8 weeks to make lashes look thicker and fuller. Lashes will return to their natural look once you stop using it. 

Are lash serums safe? 

Used correctly and per their instructions, lash serums are safe. However, they shouldn’t be applied while wearing contact lenses or makeup.  

Should an adverse reaction occur (itchy, red eyes or darkening of the eyelids), discontinue use and seek medical help.  

Shop our best eyelash serum for thicker, fuller and darker looking lashes. 


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No7 Beauty

No7 Beauty

Writer and expert