Skin Research Laboratories has revealed that it uses a prostaglandin derivative in its Neulash eyelash growth product. Called isopropyl cloprostenate, the ingredient is an analogue for prostaglandin, the glaucoma drug. Prostaglandins are controversial because they are technically a drug and a powerful one at that.

Used to treat glaucoma, one of the side effects is that eyelashes grow like weeds. Unfortunately, there are bad side effects too such as irritation, harm to vision and the actual color of eyes can change (say from brown to blue).

The makers of Neulash say that isopropyl cloprostenate is completely safe and its efficacy is increased by adding peptides into the mix, specifically in the form of polypeptide-23.