Decoding Cosmetics Claims: Eyelash Serums

With endorsements from celebrities like Brooke Shields and Sydney Sweeney, eyelash serums have become extremely popular in recent years, and have blown up on social media. In 2020, the global eyelash serum market was valued at more than $750 million. By 2031, it’s projected to reach $1.3 billion.

However, if you’re in pursuit of longer, thicker, Hollywood-worthy eyelashes, you may want to take note of some not-so-glamorous side effects that have been associated with a common ingredient in these serums – side effects that are not always clearly disclosed in the marketing.

The ingredient, isopropyl cloprostenate, is part of a group of synthetic compounds called prostaglandin analogs, or PGAs. PGAs were initially primarily used to treat glaucoma. But after some patients started developing fuller, darker eyelashes, PGAs were repurposed as the main ingredients in eyelash serums.

However, PGAs have also been linked to a number of potentially negative side effects including eye redness and itchiness, iris discoloration, the appearance of droopy eyelids and periorbital volume loss, which one doctor described as the “melting” of fat around the eyes.

A TINA.org review found that these and other potential health risks are not always disclosed in the marketing of isopropyl cloprostenate-containing eyelash serums and when they are, the disclosures can be easy to miss. A sampling follows.

• Rodan & Fields’ Lash Boost: In order to read a warning regarding isopropyl cloprostenate, an ingredient in this eyelash serum, which is marketed to promote “the appearance of longer, stronger and darker-looking lashes,” consumers must click on a “Details” tab located below the button to add the serum to their cart on the product page. Here, the company discloses, among other things, a laundry list of side effects and “other reactions” reported by users including, ironically, lash loss.

This language appears to stem from a $38 million settlement in which Rodan & Fields agreed to make certain changes to its website to resolve lawsuits alleging it failed to disclose information about the potential side effects of isopropyl cloprostenate.

• Skin Research Laboratories’ neuLASH lash enhancing serum: This company similarly tucks its isopropyl cloprostenate warning under an “Ingredients” tab on the product page, below both a button to “Add to Cart” and “Buy It Now.” Lash loss is also cited as a side effect reported by users.

• Grande Cosmetics’ GrandeLASH-MD: There is no mention of the potential side effects of isopropyl cloprostenate on this product page. Moreover, on a page that lists isopropyl cloprostenate as one of the “lash-loving ingredients” in GrandeLASH-MD, Grande Cosmetics states in an FAQ:

• Babe Original’s Essential Lash Serum: On this product page, this company notes under a “How to Use” tab that its serum contains a “small amount” of isopropyl cloprostenate but doesn’t disclose any potential health risks associated with the ingredient.

TINA.org reached out to the four companies for comment. The lone response we received came from Babe Original, which said:

Our product has undergone rigorous third-party testing to confirm its safety. Rest assured, we have not received any verified reports of Babe Original causing [the] side effects [cited by TINA.org].

The company said “appropriate warnings” are “visible to consumers on our website and packaging.”

The bottom line 

Only one eyelash serum (which contains a different PGA called bimatoprost) has been approved by the FDA, meaning the agency has evaluated the product’s safety and effectiveness. The others are over-the-counter products that lack FDA approval. That doesn’t necessarily mean they don’t work or are more dangerous – but it does mean they haven’t been vetted by the agency. (It also doesn’t mean the product approved by the FDA – Latisse – is without potential side effects – it’s not.)

In the end, when choosing to use an eyelash serum, it’s up to consumers to decide whether the advertised benefits outweigh the potential risks.

Find more of our coverage on cosmetics here.