If you've been comparing lash serums, you've probably come across the term prostaglandin. Some lash-enhancing formulas use prostaglandin analogs, while others are specifically formulated without them.
So what are prostaglandins in lash serums, why are they used, and why do some people choose to avoid them?
The story of lash serums actually began with medicine rather than beauty. Bimatoprost, a prostaglandin analog used in ophthalmology, was associated with changes in eyelash growth. That observation eventually led to the development of a prescription treatment specifically for inadequate or insufficient eyelashes.
Today, you can find both prostaglandin-containing and prostaglandin-free lash serums, giving consumers different approaches to lash care.
Understanding the difference can help you decide which type of formula fits your routine and ingredient preferences.
Quick Answer
Prostaglandins are naturally occurring signaling compounds in the body, while prostaglandin analogs are compounds designed to mimic certain prostaglandin effects. Some prostaglandin analogs can influence the eyelash growth cycle and are used in certain medical and lash-enhancing products.
Some consumers choose to avoid prostaglandin analogs because of potential ocular and cosmetic effects associated with certain ingredients in this category.
Prostaglandin-free lash serums take a different approach, using ingredients such as botanical extracts, vitamins, amino acids, oils and conditioning agents to support the appearance and condition of lashes.
Prostaglandin-free doesn't automatically mean irritation-free, and prostaglandin-containing products don't mean every person will experience side effects. The right choice depends on your individual preferences, sensitivities and goals.
What Are Prostaglandins?
Prostaglandins are naturally occurring compounds involved in a range of processes throughout the body.
Prostaglandin analogs are different. They're synthetic compounds designed to produce effects similar to certain naturally occurring prostaglandins.
In eye care, prostaglandin analogs are used in medications that help lower elevated intraocular pressure.
One of the best-known examples is bimatoprost, which is used medically and is also the active ingredient in LATISSE, a prescription treatment for inadequate or insufficient eyelashes.
The connection between prostaglandin analogs and eyelash growth was discovered after patients using certain glaucoma medications began noticing changes in their eyelashes.
That observation helped lead to the development of prescription eyelash treatments.
Why Are Prostaglandin Analogs Used in Lash Products?
The reason is fairly straightforward: certain prostaglandin analogs can influence the eyelash growth cycle.
Bimatoprost, for example, is used as a prescription treatment for inadequate or insufficient eyelashes and can increase eyelash length, thickness and darkness.
This is one reason prostaglandin-based lash products became popular.
However, the ingredient category comes with considerations beyond the desired cosmetic effect.
For some people, the potential benefits may outweigh those considerations. Others prefer a different approach to lash care and specifically look for lash serums without prostaglandins.
What Are the Potential Side Effects of Prostaglandin Analogs?
Potential effects depend on the specific ingredient, formulation and how the product is used.
Bimatoprost, for example, has been associated with potential effects involving the eyes and surrounding skin, including irritation, redness and pigmentation changes. Changes to eyelid and periorbital tissues have also been reported.
Pigmentation Changes
Bimatoprost can cause darkening of the skin around the eyes and eyelashes.
It can also cause increased brown pigmentation of the iris. This type of pigmentation change may be permanent.
Changes Around the Eyes
Prostaglandin-associated changes around the eyes have also been documented.
These can include changes to the appearance of the eyelid and the area around the eye.
Irritation and Other Ocular Effects
Bimatoprost has also been associated with ocular effects such as eye itching, redness and irritation.
This doesn't mean everyone using a prostaglandin analog will experience these effects.
It does mean they're relevant considerations when you're deciding which type of lash product you want to use.
Why Do Some People Avoid Prostaglandins in Lash Serums?
There isn't one reason everyone chooses a prostaglandin-free formula.
Some consumers simply prefer to avoid prostaglandin analogs as an ingredient category, while others may have experienced irritation or cosmetic changes with a previous product.
Here are some of the most common reasons.
1. They Want to Avoid Potential Side Effects
Some people aren't comfortable with the potential ocular or pigmentation-related effects associated with prostaglandin analogs.
Choosing a prostaglandin-free lash serum allows them to avoid that particular ingredient category.
2. They Prefer a Cosmetic Approach
Some people want a lash-conditioning product rather than a formula that relies on a pharmacological ingredient.
A prostaglandin-free formula can focus on conditioning, hydration, strengthening and reducing the appearance of breakage.
3. They Have Sensitive Eyes
The eye area is delicate, so people who are prone to sensitivity may be especially selective about the products they use around their eyes.
However, it's important to remember that prostaglandin-free doesn't mean irritation-free.
Any cosmetic product can cause irritation or an allergic reaction in an individual user.
4. They Prefer Botanical Ingredients
Some consumers prefer formulas built around plant extracts, vitamins, amino acids and conditioning oils.
This can make a prostaglandin-free formula a better fit for their overall beauty philosophy.
What Does Prostaglandin-Free Mean?
A prostaglandin-free lash serum is formulated without prostaglandins or prostaglandin analogs.
Instead, these formulas can use a combination of ingredients intended to condition lashes and support their healthier-looking appearance.
Depending on the product, that can include:
- Botanical extracts
- Amino acids
- Vitamins
- Conditioning oils
- Humectants
- Antioxidants
The exact ingredients vary from product to product.
That's why "prostaglandin-free" shouldn't be the only thing you look at when choosing a lash serum. The full formula matters.
Prostaglandin vs. Prostaglandin-Free Lash Serums
The biggest difference comes down to the ingredients and how the formula approaches lash enhancement.
| Prostaglandin-containing formulas | Prostaglandin-free formulas | |
|---|---|---|
| Main approach | Uses a prostaglandin analog or related ingredient | Uses non-prostaglandin ingredients |
| Common goal | Enhance the appearance of lash length, thickness and darkness | Condition lashes and support healthier-looking fullness |
| Ingredient types | Prostaglandin analogs plus supporting ingredients | Botanical extracts, vitamins, amino acids, oils and conditioning ingredients |
| Potential considerations | Some ingredients have documented ocular and cosmetic effects | Avoids prostaglandin analogs but can still cause individual sensitivities |
| Who may prefer it | People comfortable with this ingredient approach | People who specifically want to avoid prostaglandin analogs |
There isn't a universal "better" option.
The best choice depends on what you're comfortable using around your eyes and what you want from your lash routine.
Is Bimatoprost a Prostaglandin?
Bimatoprost is a prostaglandin analog, rather than a naturally occurring prostaglandin.
It's used medically to reduce elevated intraocular pressure and is also the active ingredient in LATISSE for inadequate or insufficient eyelashes.
This distinction matters when you're reading lash serum ingredient lists.
If you specifically want to avoid prostaglandin analogs, don't simply search an ingredient list for the word "prostaglandin."
Look at the complete ingredient list and the product's claims about what it does and does not contain.
What Ingredients Are Used in Prostaglandin-Free Lash Serums?
Prostaglandin-free formulas can use several different ingredient categories.
Amino Acids
Amino acids are commonly used in hair and lash conditioning formulas.
For example, arginine is included in some lash products as a conditioning ingredient.
Vitamins
Vitamins such as vitamin E and biotin are commonly found in lash and brow formulas designed to condition and support the appearance of healthy-looking hairs.
Botanical Extracts
Botanical ingredients can provide conditioning and antioxidant properties.
Lash formulas may use ingredients such as gotu kola, horsetail, burdock root and red clover.
Conditioning Oils
Oils such as castor, argan and almond oil can help condition the appearance of lashes and brows.
The goal isn't to find one "magic" ingredient.
A well-designed formula combines ingredients that complement one another. The goal isn't to find one "magic" ingredient. If you want to understand how different ingredients contribute to lash care, read Why Lash Serum Ingredients Matter More Than You Think.
Moon Boost: A Prostaglandin-Free Approach to Lash Care
Luna Nectar's Moon Boost Lash & Brow Enhancing Serum takes a different approach to lash care by leaving prostaglandins and bimatoprost out of the formula.
The current formula contains:
- Aloe vera
- Castor oil
- Argan oil
- Bamboo extract
- Algae extract
- Glycerin
- Vitamin E
- Horsetail extract
- Red clover extract
- Burdock root
- Gotu kola
- Biotin
- Arginine
Luna Nectar describes Moon Boost as a waterless, vegan and cruelty-free lash and brow serum. The formula is also fragrance-free and pH-balanced for the eye area.
Rather than relying on prostaglandin analogs, the formula uses botanical ingredients, vitamins, amino acids and conditioning oils to support the appearance of stronger, fuller-looking lashes and brows.
Moon Boost is also designed to be used with lash extensions.
If you're looking for a waterless prostaglandin-free lash serum, this approach may be a better fit for your ingredient preferences.
Can Prostaglandin-Free Lash Serums Still Work?
Yes, but it's important to define what you mean by "work."
A cosmetic lash serum can support the appearance and condition of lashes without using prostaglandin analogs.
However, not all prostaglandin-free formulas work in the same way, and individual results vary.
A prostaglandin-free formula may focus on:
- Conditioning lashes
- Supporting lash strength
- Reducing the appearance of breakage
- Improving hydration
- Supporting healthier-looking fullness
This is different from claiming that a cosmetic serum can treat a medical condition or guarantee a particular amount of lash growth.
Consistency also matters. Luna Nectar recommends daily use of Moon Boost and states that visible results can appear in as little as 2½–3 weeks, with fuller results typically seen within 6–8 weeks.
How to Choose a Lash Serum
When you're comparing lash serums, look beyond one ingredient or one marketing claim.
Consider Your Ingredient Preferences
If you want to avoid prostaglandin analogs, look for a clearly labeled prostaglandin-free lash serum and review the full ingredient list.
Consider Your Eye-Area Sensitivity
The skin around your eyes is delicate.
Follow the product's application instructions and stop using the product if you experience irritation or an unusual reaction.
If you have an existing eye condition or concerns about using a lash-enhancing product, speak with an appropriate healthcare professional.
Look at the Complete Formula
A product's ingredient list tells you much more than one "hero" ingredient.
Look for a formula that makes sense for your goals and preferences.
Consider Your Routine
The best lash serum is one you're comfortable using consistently.
If you wear lash extensions, check whether the product is specifically designed to be compatible with them.
Set Realistic Expectations
Lash growth and replacement happen over time.
No cosmetic lash serum can guarantee the same results for every person.
If you're new to lash serums, The Complete Guide to Lash Serums for Longer, Healthier Lashes covers how they fit into a daily lash-care routine.
Are Prostaglandin-Free Lash Serums Better?
Not necessarily.
"Better" depends on what you're looking for.
If your priority is avoiding prostaglandin analogs, a prostaglandin-free formula may be the better fit for your routine.
If you're comfortable using prostaglandin analogs and understand their potential effects, you may choose a different type of lash-enhancing product.
The important thing is knowing the difference so you can make an informed decision.
What About Lash Serums for Sensitive Eyes?
If you have sensitive eyes, ingredient selection becomes especially important.
However, don't assume that "natural" or "prostaglandin-free" automatically means a product won't cause irritation.
Instead:
- Follow the application instructions.
- Avoid getting the product directly into your eyes.
- Don't apply more product than recommended.
- Stop using it if irritation develops.
- Seek professional advice if you experience persistent or concerning eye symptoms.
For more information, see Lash Serum for Sensitive Eyes.
Final Takeaway
The story of lash serums started with a medical observation: certain prostaglandin analogs used in eye medications were associated with changes in eyelash growth.
Today, there are different approaches to lash enhancement.
Some formulas use prostaglandin analogs, while prostaglandin-free lash serums use ingredients such as botanical extracts, vitamins, amino acids and conditioning oils.
Neither approach is automatically right for everyone.
If you prefer to avoid prostaglandin analogs, understanding what you're choosing — and why — can help you build a lash routine that fits your preferences.
Read the ingredient list, understand the product's claims, follow the application directions and keep your expectations realistic.
Frequently Asked Questions
What are prostaglandins in lash serums?
Prostaglandin analogs are synthetic compounds that mimic some effects of naturally occurring prostaglandins. Certain prostaglandin analogs can influence the eyelash growth cycle and are used in some medical and lash-enhancing products.
Are prostaglandins safe in lash serums?
Safety depends on the specific ingredient, product and how it's used. Bimatoprost, for example, has documented potential ocular and cosmetic effects. If you're concerned about a prostaglandin-containing product, speak with a healthcare professional.
What are the side effects of prostaglandin lash serums?
Potential effects associated with bimatoprost include eye irritation, redness, eyelid or periorbital pigmentation and changes in iris pigmentation. Changes to the tissues around the eye have also been reported.
What does prostaglandin-free mean in a lash serum?
It means the formula is made without prostaglandins or prostaglandin analogs. Prostaglandin-free formulas may instead use botanical extracts, vitamins, amino acids, oils and other conditioning ingredients.
What is the best prostaglandin-free lash serum?
There isn't one formula that's best for everyone. Look for a product that clearly states it doesn't contain prostaglandin analogs and choose a formula that fits your ingredient preferences, eye-area sensitivity and lash-care goals.
Does Moon Boost contain prostaglandins?
No. Luna Nectar states that Moon Boost is formulated without prostaglandins and bimatoprost. Its formula uses botanical extracts, vitamins, amino acids, oils and other conditioning ingredients instead.
Can you use a prostaglandin-free lash serum with lash extensions?
Some can. Always check the individual product's instructions. Moon Boost is designed to be compatible with lash extensions.
How long does a prostaglandin-free lash serum take to work?
Results vary by person and formula. Luna Nectar states that visible Moon Boost results can appear in as little as 2½–3 weeks, with fuller results typically seen within 6–8 weeks of consistent daily use.