Earlier this week it was reported that a Californian woman is suing Sephora after claiming she contracted herpes from using one of the cosmetic store's lipstick samples.
And now a university lecturer is warning others to avoid using makeup samples in store confirming that they can indeed lead to herpes and even blindness.
Amreen Bashir, Lecturer in Biomedical Science at Aston University, explains that the pathogens that cause Herpes can often be found on cosmetic products, reports Daily Mail.
Writing for The Conversation Bashir says: "Cosmetic products contain preservatives to help slow down the growth of microbes, but they can become contaminated if people use non-sterile applicators or fingers to apply products, or if the products are poorly handled and stored."
Bashir adds: "Often, beauty blenders and brushes are dampened to help the application of eyeshadows or foundation. But this environment has the potential to promote rapid bacterial growth."
Worryingly it is not just herpes that shoppers are at risk of with Bashir explaining that sharing mascara wands can cause "pink eye" of which the symptoms include discharge, redness and, in extreme cases "irreversible blindness."
Bashir explains: "I know many friends who have been left with a 'pink eye' after sharing mascara or using ancient mascara that has been sitting in their makeup bags."
The lecturer recommends avoiding sharing cosmetic products, especially those at cosmetic counters.
This comes just days after it was reported that a Sephora customer will be suing the cosmetic brand after she claimed she contracted herpes after using one of their "testers".
The woman said she visited a store in Hollywood back in October 2015 and used one of the sample lipsticks on display.
She claims she ended up with the incurable disease on her lip, according to court documents obtained by TMZ.
The woman, who hasn't been identified, says doctors diagnosed her with the STD.
She said she did not have herpes before going to the Sephora store.
The lawsuit claims Sephora failed to warn her, as well as other customers, of the dangers of using lipstick samples.
She said other cosmetic stores offer individualized samples or help from staff to avoid contracting diseases like herpes.
The woman is suing the company for an unspecified amount for causing emotional distress due to the "incurable lifelong affliction".
A spokesperson for Sephora said: "While it is our policy not to comment on litigation, the health and safety of our clients is our foremost priority.
"We take product hygiene very seriously and we are dedicated to following best practices in our stores."
Herpes: The facts
Most people who are infected with the herpes virus never develop signs and symptoms.
The virus may lie dormant for years and the recurrence of sores triggered by a virus, hormonal changes, stress, fatigue or changes in the immune system.
Currently, there is no cure for the virus.
Most people contract HSV-1 in childhood, through skin-to-skin contact with an infected adult.
It is transmitted through secretions or sores on the skin and can be spread through touching, kissing, or sharing objects such as razors, towels, toothbrushes or cutlery.
HSV-2 is usually transmitted sexually and can increase the risk of catching and spreading HIV, the disease that causes AIDS.
Little is known about any link between HSV-1 and HIV/AIDS, although it can lead to other serious complications such as encephalitis, a serious illness causing inflammation of the brain.