Never share your mascara or public makeup testers, and replace your tube every 3 to 6 months to avoid the transmission of bacteria and eyelash mites (Demodex) that can cause irritation and eyelash loss.

noli's read

The recommendation not to share mascara is based on very solid microbiology. An observational study published in the Journal of Applied Microbiology (Amr et al., 2019) revealed that nearly 80% of used mascaras analyzed were contaminated with bacteria, as the moist environment of the tube promotes their proliferation once the preservatives are degraded. Regarding eyelash mites (Demodex), an expert analysis published in the journal Eye (Fromstein et al., 2018) confirms that these tiny organisms are transmitted by direct or indirect contact via cosmetic products, which can cause eyelid discomfort and temporary eyelash loss in cases of overpopulation. Replacing the product every 3 to 6 months is a golden rule also validated by regulatory authorities to prevent the accumulation of germs. The only nuance concerns dark circles: their appearance is primarily linked to vascularization and fatigue, not the activity of these mites. Otherwise, the prevention and hygiene advice in this post is excellent for eye health.

the sources

No named source held this one up — that absence is part of the verdict.