The Chemical Consequences of Unregulated Lash Serums

Are voluminous lashes worth sunken eyes, orbital fat loss, and the probable vision loss? The 26-paged class-action suit filed in 2021 by Genna Ribak cites these symptoms as side effects in her case against Sephora, a global makeup supplier, in relation to their GrandeLASH-MD lash growing serum. GrandeLASH-MD is marketed as “a cult-favorite lash enhancing serum that promotes the appearance of longer, thicker-looking lashes in four to six weeks.” The product claims that it is “paraben-free” and “cruelty-free,” and presents its key ingredient as hyaluronic acid (Sephora, 2022). While ingredients and claims appeared appealing at first glance, a mass consumer response led cosmetic scientists to look into the active ingredients of GrandeLASH and other lash serums due to their unusual side effects. 

The chemical at fault is isopropyl cloprostenate (C25H35ClO6O), a synthetic prostaglandin that has been popularized in lash and brow growth cosmetics in the recent decade. This ingredient gained its prominence in its original form, 0.03% bimatoprost, as an active ingredient in glaucoma medicine for patients who suffered hypotrichosis, or hair loss (Law, 2010).

The Ribak complaint claimed that GrandeLash did not seek proper approval to sell these enhancement serums, which is required by law per California’s Health & Safety Code §§ 109875, et seq (Ribak v. GrandeLash, 2021). The complaint also enumerated many of the side effects of the GrandeLASH-MD lash and brow enhancement serum, including “​​iris discoloration, the development of growths in the eye, and the complete loss of eyelashes.” The Ribak complaint, paired with the hundreds of accompanying customer complaints, reveals just how much more the Federal Government should be involved in makeup regulation. 

The Food and Drug Administration has barred only 11 chemicals added to cosmetics (FDA, 2022). Comparing the ban of 11 ingredients in the United States to the 1,328 ingredients banned in the European Union (Regulation (EC), 2009) has led to the formation of a “clean beauty” movement in the United States whose primary focus is implementing transparency with brand ingredients, and finding elements that are holistically better for the skin. The campaign has also diverted its attention to products that cause harm to consumers, such as GrandeLASH. Still, it is a matter of whether members should advocate for stricter regulation of cosmetics in the United States.

Isopropyl cloprostenate is a synthetic prostaglandin made to mimic the effects of 0.03 % bimatoprost compound Latisse. Ophthalmologist Dr. Simon Law describes bimatoprost as “a synthetic product initially designed pharmacologically to reduce the intraocular pressure for the treatment of glaucoma” (Law, 2010). Bimatoprost is categorized as a fatty acid amide, a family known as prostamides. Its structural similarity to prostaglandins has piqued the interest of researchers who observed instances of hair growth associated with the blocking of prostaglandin in drugs such as Minoxidil and Latanoprost (Law, 2010). Bimatoprost became the model drug for eyelash growth in glaucoma patients due to the drug’s ability to prolong the anagen phase of eyelash growth (Law, 2010). Another study similarly found the compound to be, “noninvasive, effective, and well-tolerated,” and described Bimatoprost as a potential “treatment option for eyebrow hypotrichosis” (Chanasumon, 2018).

Figure 1. The Five Hair Growth Stages as Seen in Eyelashes.

While this drug proved to have positive effects in glaucoma patients, researchers also observed adverse side effects to 0.03% bimatoprost. A 2004 study sought to research the side effects of bimatoprost therapy by cross-referencing the results of their research with known side effects. This study focused on three glaucoma case studies. Each patient suffered from the deepening of the eye sulcus due to orbital fat loss (Peplinski, 2004). 

Figure 2. Effects of Topical Bimaprost in Glaucoma Patients

In light of these rapidly emerging adverse side effects to Bimatoprost, the FDA has previously issued a warning letter in 2011 advising the beauty company RapidLash against the use of isopropyl cloprostenate in their NeuLash lash growth serum. (FDA, 2011). The letter stated that ‘NeuLash’ contained isopropyl cloprostenate which, under the conditions of use prescribed in the labeling, may cause the following injuries: ocular irritation, hyperemia, iris color change, macular edema, ocular inflammation, and interference with intraocular pressure reduction therapy.” Per this letter, GrandeLash violated a similar code as RapidLash (section 301(a) of the Act (21 U.S.C. § 331(a)) where both brands misrepresented the active ingredients in their lash serums and put their consumers at risk of unregulated synthetic prostaglandin use (FDA, 2011).

The American beauty industry has capitalized on women’s insecurities for years, going to extreme lengths to secure a profit. From using acidic soaps to putting bleaching agents in the air, the evolution of beauty products has historically remained unsafe. The mimicry of glaucoma medicine in lash and eyebrows has had adverse effects on multiple women across the nation and should prompt consumers to think critically about the overall price of beauty. Fortunately, instances like these have catalyzed clean beauty movements across the United States and fostered the creation of apps such as CosmEthics and ThinkDirty, which are databases that can be used to detect harmful ingredients in popular cosmetic brands. Perhaps these may be the best options for mindful and health-conscious consumers to use in the interim until more targeted cosmetic chemical legislation is instated.

Edited by Sabrina Jin


Chanasumon, N., Sriphojanart, T., Suchonwanit, P. (2018). Therapeutic potential of bimatoprost for the treatment of eyebrow hypotrichosis. Drug design, development and therapy, 12, 365–372.

Food And Drug Administration. (2011). Warning Letter. 2011—Lifetech Resources LLC.

Food and Drug Administration. (2022). Prohibited & Restricted Ingredients in Cosmetics. FDA.

Law S. K. (2010). Bimatoprost in the treatment of eyelash hypotrichosis. Clinical ophthalmology (Auckland, N.Z.), 4, 349–358.

Peplinski, L. S., & Albiani Smith, K. (2004). Deepening of lid sulcus from topical bimatoprost therapy. Optometry and vision science: official publication of the American Academy of Optometry, 81(8), 574–577.

Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products, (2009) 342 OJ L.

Ribak vs. GrandeLash Cosmetics LLC. (2021). The US. District Ct.

Sephora. (n.d.) GrandeLASH™—MD Lash Enhancing Serum—Grande Cosmetics.

Image Citations

Peplinski, L. S., & Albiani Smith, K. (2004). Deepening of lid sulcus from topical bimatoprost therapy. Optometry and vision science: official publication of the American Academy of Optometry, 81(8), 574–577.

Welsch, C.  (2020). Understanding the Hair Growth Cycle. Toppik Blog. Retrieved February 13, 2022.

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