The Hidden Dangers of Secondhand Beauty Products, Including Used Lip Gloss

Between makeup-sharing culture on social media and the rise of resale sites for secondhand cosmetics, buying, borrowing, or trying “gently used” beauty products has become surprisingly normal. But dermatologists agree: when it comes to makeup, secondhand almost always means higher risk.

Just How Dirty Is Used Makeup?

Makeup sponges, for example, because they’re routinely used wet, creates an ideal breeding ground for bacteria and fungi. And only a small fraction of products had ever actually been cleaned, and a notable share are  dropped on the floor at some point, especially sponges.

The bacteria most commonly identified included Staphylococcus aureus, E. coli, and Citrobacter freundii, organisms capable of causing skin infections, urinary tract infections, and even food poisoning.

What Can Actually Go Wrong?

Sharing or reusing someone else’s makeup opens the door to several categories of risk.

Eye Infections

Mascara, eyeliner, and eyeshadow can transfer bacteria directly to the eye area, raising the risk of conjunctivitis, also known as pink eye, corneal inflammation, and other ocular infections.

Skin Infections and Allergic Reactions

Bacteria like staph and strep can thrive in shared products. Used makeup can also harbor Demodex mites, which have been linked to eyelid irritation and rosacea flare-ups.

Viral Transmission

Herpes simplex virus, the virus responsible for cold sores, can spread through shared lip products. The virus is capable of surviving on a dry surface for weeks, so a lipstick or gloss does not need to have been freshly used to pose a risk.

Fungal and Yeast Overgrowth

Products purchased secondhand, particularly from unknown sellers, may carry fungal contamination that is not visible to the eye.

Why Secondhand Cosmetics Add an Extra Layer of Risk

Buying used makeup online through resale platforms comes with its own uncertainty. Dermatologists point out that even when a seller claims a product is unused, buyers have no way to verify how it was stored, how long it has been open, or whether it was contaminated before resale.

Some dishonest sellers have also been known to repackage used products as new. Products from major brands typically contain preservatives designed to extend shelf life, but smaller, preservative-free labels may carry a higher risk of harboring bacteria or mold once opened.

How to Protect Yourself

  • Skip sharing anything that touches your eyes, lips, or mucous membranes, including mascara, eyeliner, lip gloss, and lip balm.
  • If buying secondhand, stick to lower-risk formats like powders or products dispensed through a pump or small opening, such as liquid foundation or primer.
  • Avoid creamy or jarred products entirely.
  • Never buy used mascara, eyeliner, or lip gloss. Once an applicator is contaminated, the whole product usually is too.
  • Wash makeup sponges and brushes regularly and let them fully dry before reuse.
  • Respect expiration windows. As a general rule, replace mascara, liquid eyeliner, and sponges every three months; lip gloss and stick eyeliner every six months; and lipstick annually.
  • Trust your senses. If a product smells off or does not seem right, do not risk it.

The Bottom Line

Convenience and cost savings are tempting, but when it comes to anything that touches your eyes, lips, or skin, a personal, unshared product is always the safer choice.

References:

  • “Beauty blunders: The potential dangers of sharing makeup.” Curology
  • “Used makeup products could be contaminated with dangerous bacteria.” WXYZ / Scripps News
author avatar
Dr. Jane Yoo Board-Certified Dermatologist and Mohs Surgeon
Jane Yoo, MD, MPP, is a Korean American board-certified dermatologist and fellowship-trained Mohs surgeon based in Midtown Manhattan. She is a Clinical Assistant Professor at the Icahn School of Medicine at Mount Sinai and the founder of Jane Yoo MD, PLLC and the Clinical Research Center of New York. Dr. Yoo holds an undergraduate degree from MIT and a Masters of Public Policy from Harvard's Kennedy School of Government. She completed her Mohs micrographic surgery fellowship at Yale. Her clinical and research focus spans aesthetic clinical trials including injectables and laser technology, skincare formulation and sunscreen science, K-Beauty and skin of color, ultrasound guided filler dissolution, artificial intelligence and beauty tech. Dr. Yoo's research is indexed under ORCID 0000-0002-7112-8963.