The Truth About Lash Serums: Nima Busts Common Eyelash Growth Myths

Hi, Nima here. It's been 15 years since I developed our first lash serum which is today UKLASH, and I’ve seen firsthand how its popularity has skyrocketed since then. 
But with that growth, I’ve also seen a rise in myths and misinformation - especially online. So I’m here to set the record straight, tackling the biggest misconceptions about lash serums, addressing common concerns and sharing the real facts you need to know for longer, fuller and healthier eyelashes! 

1. Myth: Some Lash Serums Contain Hormones

This is a completely false and misleading claim, often spread by new brands with very little industry knowledge. Many of these brands use scaremongering marketing tactics to confuse the consumer and push their own products. What they’re really mislabeling are Prostaglandin Analogues (PGAs), which are not hormones. There’s no scientific reasoning for using hormones as they affect the entire body rather than just eyelashes, and would also be extremely expensive and impractical.  
I'll try to clear up the confusion here and identify the key differences between Prostaglandin Analogues and Hormones, so you know exactly what’s in your lash serum—and what’s not...

Prostaglandin Analogues (PGAs) – The Lash Growth Activators
What are they? - Synthetic compounds that mimic Prostaglandins, which are natural substances that we have in our body to regulate various functions including lash growth.
How do they work? - PGA’s act locally where they’re applied - stimulating the lash follicles to specifically extend the growth phase of your lashes, leading to longer and thicker-looking eyelashes over time.
Do they affect the rest of the body? - No! Unlike hormones, PGA’s only work where they’re applied and do not travel through the bloodstream.

Hormones - The Body’s Chemical Messengers
What are they? - Hormones are chemical messengers that travel through the bloodstream, affecting various parts of the body.
How do they work? - They regulate a wide range of bodily functions, from metabolism to mood - but they don’t work in the same way as Prostaglandin Analogues which are localised, not affecting other parts of the body like hormones do.
Are they in lash serums? - No! Using hormones in a lash serum would make zero scientific sense, as they have more of an impact on the whole body, not just the eyelashes and would be expensive and impractical.

2. Myth: Lash Serums Cause Orbital Fat Loss

I’ve seen this claim pop up online. While I can't speak for every product on the market, I can confidently speak for ours. Our serums undergo rigorous safety testing, including Dermatologist and Ophthalmologist evaluations, and none have shown this side effect.

Additionally, there is no scientific evidence or credible research linking lash serums or Prostaglandin Analogues (PGAs) to orbital fat loss.

Here’s The Truth:
○ Orbital fat loss is typically caused by ageing, genetics, or certain medical conditions - not cosmetic products.
○ Lash serums work locally on the lash line, stimulating lash follicles for longer, fuller-looking lashes—they should not affect fat tissue.
○ Like any skincare or cosmetic product, lash serums can have minor side effects for some users, such as temporary irritation or pigmentation changes, but fat loss is not one of them.
○ Incorrect Application (like applying too much product too close to the eye) may cause irritation, but it won’t break down fat or change facial structure.

The best way to maximise results and avoid irritation is to use your lash serum as directed. If you have a specific medical condition or just a general concern, it’s always best to check with a medical professional.

3. Myth: All Lash Serums Cause Skin Darkening Around the Eyes

I get asked about this a lot. Some lash serums—especially those with high levels of Prostaglandin Analogues (PGAs), can cause temporary skin darkening along the lash line, however, it’s a myth to say this applies to all lash serums and is certainly not the case for the original UKLASH Eyelash Serum, if used correctly as directed. 

Here’s what you need to know:
○ Certain lash serums with strong levels of PGAs can increase melanin production, leading to temporary hyperpigmentation, particularly in those with sensitive skin or when the serum is over-applied.
○ This side effect is usually temporary and fades over time once the product is discontinued.
○ It’s more noticeable on lighter skin tones, but it can vary from person to person.
○ Proper application matters—using too much or applying beyond the lash line increases the risk of pigmentation changes. 

At UKLASH, our lash serum is specially formulated for both safety and effectiveness. We conduct clinical studies and undergo Dermatologist and Ophthalmologist testing to ensure the highest standards. We use gentle yet powerful ingredients that deliver longer, fuller lashes without compromising skin health. We always recommend doing a patch test before introducing any new product into your routine and consulting with a Dermatologist if you know you are particularly sensitive when introducing new products into your routine.

I hope this has cleared up any misconceptions you might have heard and helps you understand how lash serums work to grow stronger, longer and fuller-looking lashes.

As the #1 lash serum brand, we at UKLASH have collaborated with Scientists, Biologists, Chemists & Formulators with over 55+ years of experience to be the first brand to bring you three different eyelash serums, catering to a variety of different needs:

The Original Eyelash Serum - Includes low levels of Prostaglandin Analogue to stimulate fast lash growth
The Complex Peptide Eyelash Serum - Prostaglandin-free, powered by 6 peptides
The Sensitive Eyelash Serum - Prostaglandin-free. Enriched with antioxidants and gentle active ingredients designed for sensitive skin types

If you’re still not sure which Eyelash Serum is right for you, take our quiz here in just 30 seconds and find the perfect serum to achieve your dream lashes!
If you have any questions about our products or lash serums in general, we’re always here to help. Feel free to reach out to our friendly customer support team at contact@uklash.com, or you can email me directly at nima@uklash.com

FAQs About Lash Serums & Prostaglandin Analogues

1. Do lash serums contain hormones? 

No, lash serums do not contain hormones. Some formulas include Prostaglandin Analogues (PGAs), which are synthetic compounds that stimulate eyelash growth locally. Unlike hormones, PGAs do not travel through the bloodstream or affect other parts of the body.

2. Can lash serums cause orbital fat loss?

Our rigorous safety testing, including Dermatologist and Ophthalmologist evaluations, has not orbital fat loss as reported side effects. While there are online claims around this,  there is no scientific evidence linking lash serums to orbital fat loss. Orbital fat loss is typically caused by ageing, genetics, or certain medical conditions, not by topical cosmetic products like lash serums. 

3. Do all lash serums cause skin darkening?

Not all lash serums cause skin darkening. Some serums with high levels of Prostaglandin Analogues may lead to temporary hyperpigmentation, but this effect is rare and fades after stopping use. Proper application—keeping the serum on the lash line and not the skin—can help prevent this.

4. Are Prostaglandin Analogues safe for eyelash growth?

Yes, Prostaglandin Analogues have been extensively studied and are considered safe when formulated at the right levels, combined with the appropriate ingredients, and used as directed. Prostaglandin Analogues as an active ingredient remain the most effective ingredient for fast lash growth. However, those with sensitive skin types may experience mild irritation and can look towards using a Prostaglandin-free lash serum such as our Complex Peptide Eyelash Serum or Sensitive Eyelash Serum. 

5. How long does it take to see results from a lash serum?

Most users notice longer and fuller lashes within 4 to 8 weeks, with full results appearing after 12 weeks of consistent use. Consistency and proper application are key to achieving optimal results.

6. What’s the best way to apply a lash serum?

1. Remove makeup with an oil-free remover or cleanser
2. Apply one stroke of the serum to your upper lash line. (One dip is sufficient for both eyes)
3. For best results, apply in the PM and allow the serum to work overnight. If applying in the AM - make sure the serum has fully dried before following with your makeup routine