Most people never read the ingredient list on a lash serum. It is tiny, it is full of long chemical names, and the front of the box usually tells a much more exciting story. But if you want to avoid prostaglandin analogs, the back of the box is where the real answer lives.
This guide shows you exactly which names to look for, where they tend to hide in an ingredient list, and what to do when a label is vague or missing. For the bigger picture on why this matters, see our pillar guide to prostaglandin-free lash serum.
Keep this page handy on your phone the next time you shop. Thirty seconds of label reading can save you a lot of second-guessing later.
Key takeaways
- Prostaglandin analogs rarely use the word “prostaglandin” on a label. Look for names ending in -prost, -prostenate, -prostamide or -prostenolamide.
- The most common cosmetic analogs are isopropyl cloprostenate and ethyl tafluprostamide (also listed as DDDE) [1].
- Some serums have been found to contain analogs that were not declared on the label at all [4].
- If a brand will not share a full ingredient list or confirm it is prostaglandin-free, treat that as a reason to look elsewhere.
Why prostaglandin analogs are worth spotting
Prostaglandin analogs are the ingredient family behind prescription Latisse (bimatoprost). They do affect lashes, which is why they show up in cosmetic serums too. They are also linked to darker eyelid skin, permanent iris color change and fat loss around the eyes [2][3]. We explain each of those in detail in prostaglandin lash serum side effects.
In Europe, the Scientific Committee on Consumer Safety reviewed two of the most common cosmetic analogs, isopropyl cloprostenate and ethyl tafluprostamide, and stated it was not able to conclude they were safe at the concentrations proposed for cosmetics. The committee also raised concerns because these substances are potent at very low concentrations, especially in products used near the eye [5].
In the United States, cosmetics generally do not need FDA approval before they are sold [6]. That puts more of the responsibility on you, the shopper, to know what is in the bottle.
How common are prostaglandin serums?
By the numbers
- In a review of 79 lash-lengthening cosmetics (Couteau and Coiffard, Ann Pharm Fr, 2026), about 30% contained a prostaglandin analog [1].
- The same study identified six different analogs, with ethyl tafluprostamide (DDDE) and isopropyl cloprostenate the most common [1].
- In a lab test of 64 serums bought online (Rahman et al., J Pharm Biomed Anal, 2022), 3 products contained bimatoprost that was not listed on the package, and 8 contained other analogs [4].
The takeaway: roughly one in three lash cosmetics in that sample used a prostaglandin analog, and label reading is not a perfect safeguard. It is still the best first step you have.
The names to look for
Here are prostaglandin analogs that published studies have identified in lash products. Brands may use slight spelling variations, so look for the root of each name.
| Name on the label | Also seen as | Notes |
|---|---|---|
| Isopropyl cloprostenate | None | One of the most common cosmetic analogs [1][3] |
| Ethyl tafluprostamide | Dechloro dihydroxy difluoro ethylcloprostenolamide, DDDE | Among the most common in the 2026 study [1] |
| Bimatoprost | None | The active drug in prescription Latisse; found undeclared in some cosmetics [4] |
| Norbimatoprost | None | Identified in cosmetic serums [1][2] |
| Methylamido dihydro noralfaprostal | None | Listed among analogs in serums studied in 2022 [2] |
Quick pattern-matching tips
- Scan for the letters prost anywhere in a word. Cloprostenate, tafluprostamide, bimatoprost and noralfaprostal all contain it.
- Watch for long names that include cloprostenol, dihydroxy or difluoro together. These often point to the DDDE family.
- Abbreviations like DDDE in an ingredient list are a red flag worth looking up.
- Do not rely on the word “prostaglandin” appearing at all. In the products reviewed for the 2022 Jamison study, customer-facing ingredient lists often did not mention prostaglandin analogs [2].
A practice run: reading a sample label
Here is a made-up ingredient list, similar in style to what you might see on a box. It is not from any real product.
Water, Butylene Glycol, Glycerin, Panthenol, Hydroxyethylcellulose, Isopropyl Cloprostenate, Sodium Hyaluronate, Phenoxyethanol.
Read it slowly, one comma at a time. Water, butylene glycol and glycerin are common bases and moisturizers. Panthenol is a conditioning ingredient. Hydroxyethylcellulose is a thickener. Then comes isopropyl cloprostenate, and the letters “prost” tell you right away that this sample is not prostaglandin-free. The ingredient is listed after the thickener, so it may make up only a small part of the formula. That does not change anything, because the SCCS noted that these substances are potent at very low concentrations [5].
Now try the same scan on your own products. If none of the names contain “prost” and nothing looks like the long DDDE name, you are most of the way there. For anything that still seems unclear, look up the name or ask the brand. If your eyes are easily irritated, also look for fragrance and other common irritants. Our guide to lash serum for sensitive eyes explains what else to watch for. For an overview of the ingredient types you will see, read lash serums explained.
Where to find the full ingredient list
Front-of-box claims are marketing. The ingredient list is what you need, and it can be in several places:
- The outer carton, usually on the back or bottom in small print.
- The product page on the brand’s own website, often under a tab labeled “Ingredients” or “Details”.
- A retailer’s listing, though these are sometimes outdated, so cross-check with the brand.
- The brand’s customer service team, which should be able to email you a current list.
Ingredient lists can change when a product is reformulated. If you have used a brand for years, it is worth checking again.
Label red flags
Even when you cannot find a named analog, some signs suggest you should dig deeper:
- No ingredient list anywhere, or only a short list of “key ingredients”.
- A list that differs between the box, the brand site and the retailer.
- Products bought from unfamiliar marketplace sellers or overseas sites. The 2022 lab study tested serums bought online and found undeclared bimatoprost [4].
- Packaging warnings about possible eyelid darkening or eye color change. These warnings are a strong hint that a prostaglandin analog is present.
- Claims that sound like a drug, such as promises to treat lash loss. The FDA notes that claims to restore hair growth can make a product a drug in the eyes of the law [6].
What “prostaglandin-free” should mean
A prostaglandin-free lash serum should contain no prostaglandin analogs at all, not just a smaller amount. When a brand says “prostaglandin-free”, the full ingredient list should back that up with no -prost names anywhere.
Prostaglandin-free formulas tend to rely on other ingredients, such as conditioning peptides, amino acids, panthenol and plant oils. The 2026 Couteau study noted that the non-prostaglandin serums it reviewed used ingredients like castor oil, amino acids, panthenol and peptides [1]. You can dig into one popular example in our guide to peptides in lash serums.
Questions to ask a brand
If anything feels unclear, email the brand before you buy. Reasonable questions include:
- Does this product contain any prostaglandin analog, including isopropyl cloprostenate or DDDE?
- Can you send the complete, current ingredient list?
- Has the formula changed in the last year?
- Where is the product made, and are authorized retailers listed on your site?
A clear, quick answer is a good sign. Evasive answers or none at all tell you something too. Our checklist for choosing a prostaglandin-free lash serum covers more of what to look for, and our comparison of Latisse and over-the-counter serums explains how prescription and cosmetic products differ.
When to see an eye doctor
If you have already been using a serum and later learn it contains a prostaglandin analog, check your eyes in good light. See an ophthalmologist or optometrist if you notice:
- A change in the color of your iris.
- Darkening of the eyelid skin that does not fade after stopping.
- A hollow or sunken look, or a deeper upper lid crease.
- Eye pain, ongoing redness, light sensitivity or vision changes.
People with glaucoma, eye inflammation or a history of eye surgery should talk with their eye doctor before using any lash serum [3]. If you are unsure where to start, our lash resources page explains how to find an eye care professional.
Looking for a prostaglandin-free lash serum?
XXtraLash is a prostaglandin-free eyelash serum that conditions lashes for a longer-looking, fuller-looking lash line. Each 3 mL bottle comes with a precision brush for applying right along the lash line.
Frequently asked questions
What is the most common prostaglandin analog in lash serums?
In a 2026 study of 79 lash cosmetics, the most common analogs were ethyl tafluprostamide (also called DDDE) and isopropyl cloprostenate. Bimatoprost and norbimatoprost were also found.
Will the label always say prostaglandin?
No. Ingredient lists use the chemical name, such as isopropyl cloprostenate, not the word prostaglandin. Researchers have also found some serums with prostaglandin analogs that were not listed at all.
Is DDDE a prostaglandin?
DDDE stands for dechloro dihydroxy difluoro ethylcloprostenolamide, also called ethyl tafluprostamide. It is a prostaglandin analog and was one of the most common analogs found in cosmetic lash serums in a 2026 study.
Are peptides the same as prostaglandins?
No. Peptides such as myristoyl pentapeptide-17 are short chains of amino acids and belong to a different ingredient class. Many prostaglandin-free lash serums use conditioning peptides instead of prostaglandin analogs.
What should I do if my serum contains a prostaglandin analog?
You can decide whether to keep using it based on the known side effects. If you notice eye color change, lid darkening, hollowing, pain or vision changes, stop and see an eye doctor.
Related reading
- Prostaglandin-Free Lash Serum: What It Means and Why It Matters
- Prostaglandin Lash Serum Side Effects: Darkened Lids, Eye Color and Fat Loss
- How to Choose the Best Prostaglandin-Free Lash Serum
- Latisse vs. Over-the-Counter Lash Serums: What’s the Difference?
- Is Lash Serum Safe? What to Know Before You Start
- Lash Serums Explained: Types, Ingredients and How to Choose
Sources
- Couteau C, Coiffard L. Prostaglandin analogues in cosmetic products formulated for eyelash lengthening. Ann Pharm Fr. 2026
- Jamison A, et al. Do Prostaglandin Analogue Lash Lengtheners Cause Eyelid Fat and Volume Loss? Aesthet Surg J. 2022
- What You Should Know About Eyelash Growth Serums, American Academy of Ophthalmology
- Rahman MS, et al. Screening and quantification of undeclared PGF2α analogs in eyelash-enhancing cosmetic serums using LC-MS/MS. J Pharm Biomed Anal. 2022
- Scientific Committee on Consumer Safety. Prostaglandins and prostaglandin-analogues used in cosmetic products. European Commission, 2022
- Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?), U.S. Food and Drug Administration
