Researchers compared three medicines in mice, but the findings do not establish a new treatment for human hair loss or eyelash growth.
A new study examining prostaglandin analogues and hair growth has compared three medicines—bimatoprost, latanoprost and travoprost—with minoxidil in mice.
Published online on 26 October 2026 in the Indian Dermatology Online Journal, the research found differences in hair growth measurements over four weeks. While the results may guide future research, the experiment was conducted on shaved mouse skin, not human scalps or eyelashes. PubMed
What did the researchers study?
The researchers divided 40 male mice into five groups of eight. Each group received one of the following: a vehicle control, 5% minoxidil, 0.005% latanoprost, 0.03% bimatoprost or 0.004% travoprost.
The treatments were applied daily to shaved skin on the animals’ backs for 28 days. The team assessed hair growth using photographs and measurements including hair density, follicle diameter and visible regrowth.
What did the mouse study find?
All three prostaglandin analogues produced higher measured hair density than the vehicle control. Latanoprost and bimatoprost also showed higher hair-density measurements than minoxidil during the study period.
Latanoprost showed earlier visible regrowth by day 15, while bimatoprost showed the greatest reported regrowth by day 28. The researchers also reported greater follicle diameter in the three prostaglandin analogue groups than in the control and minoxidil groups.
These results describe what happened under the conditions of this experiment. They do not establish that any of the three medicines works better than minoxidil for human hair loss.
What does this mean for eyelashes?
Bimatoprost is already used as a prescription treatment for inadequate eyelash growth in some countries, including the United States. Its use for eyelashes is supported by human clinical evidence; this mouse study did not discover that effect.
The new study’s value lies in comparing three related compounds under the same experimental conditions. However, mouse back hair and human eyelashes differ in their growth cycles and environment.
The researchers did not test human eyelashes or compare the medicines with commercial lash serums. The study therefore cannot tell us whether latanoprost or travoprost is more effective than bimatoprost for eyelash growth.
Why does the short study period matter?
Each group contained only eight mice, and treatment continued for four weeks. The authors noted that minoxidil did not show noticeable growth during their experiment and that its effects may take longer to become apparent.
The short observation period limits the comparison. Larger and longer studies—and eventually well-designed human trials—would be needed to establish whether the findings translate into clinical benefit.
Eyelash growth and safety
Products marketed for fuller lashes do not all contain the same ingredients. Some are cosmetic conditioning serums; others contain pharmacologically active substances.
Bimatoprost can cause effects including eye irritation and darkening of eyelid skin. Its US prescribing information also warns that increased iris pigmentation may occur and is likely to be permanent. Changes around the eyes have been reported with prostaglandin-related medicines.
In February 2026, the European Union’s Scientific Committee on Consumer Safety issued an opinion on three different prostaglandin analogues used in cosmetic products. It concluded that the available evidence did not support considering them safe for eyelash and eyebrow growth cosmetics, citing their pharmacological activity and insufficient data to rule out potential reproductive or developmental effects.
Those three cosmetic ingredients were not the three medicines tested in this mouse study. The committee’s opinion also should not be confused with a regulatory ban. It highlights why each ingredient and formulation needs its own safety assessment.
What should readers take away?
The mouse study adds comparative information for researchers. It does not establish a new eyelash treatment or prove that the tested medicines are superior to minoxidil for people.
Anyone considering a product intended to stimulate eyelash growth should discuss its ingredients and potential risks with a qualified healthcare professional, particularly because products are applied close to the eyes.
Original study
Navale VS, Marathe PA, Patil SP. In Vivo Study of Topical Bimatoprost, Latanoprost, Travoprost in Comparison with Minoxidil on Hair Growth in C57BL/6 Mice. Indian Dermatology Online Journal. Published online 26 October 2026.
DOI: 10.4103/idoj.idoj_774_25 Additional source: European Commission Scientific Committee on Consumer Safety: Opinion on prostaglandin analogues used in cosmetic products, SCCS/1680/25.