For decades, “protect your drink” has been one of the foundational unofficial rules of nightlife. The threat of unwittingly consuming a date-rape drug looms so large that steps to combat that risk have become a routine part of any night out. There are even new products designed specifically to defend against having a drink spiked.
That level of diligence is, unfortunately, necessary. While the nature of date-rape drugs makes it hard to track how frequently they are used, evidence suggests that millions of people are sexually assaulted every year after consuming drugs they took involuntarily.
Researchers in Korea have come up with a simple and effective idea that they hope will give people an easy new way to protect themselves. It’s a temporary tattoo that can instantly detect the presence of one of the most common date-rape drugs from a single drop of a suspect drink. The tattoo is made with a mix containing a chemical receptor that reacts to even tiny amounts of gamma-hydroxybutyric acid (GHB) — an odorless, tasteless drug that is often used in what authorities call drug-facilitated sexual assault.
When the tattoo comes in contact with GHB, it changes color from yellow to red, providing a clear indication within one second that a beverage has been tampered with.
There are other products on the market that can be used to test drinks for GHB, along with other date-rape drugs like Rohypnol and ketamine, but they are difficult to use discreetly and can take up to five minutes to provide results. Someone wearing one of the tattoos, on the other hand, could easily dip their finger into their beverage, touch the tattoo and know right away whether it has been tampered with. All this can be done in secret because the tattoos can be made in any shape, so their true purpose won’t be obvious to the people around you. The researchers behind the tattoos hope their innovation will one day provide a “proactive and accessible solution” that will allow people to easily and subtly protect themselves.
This tattoo-like sticker, which can be printed in a variety of designs, detects the presence of a drug often used to “spike” drinks — the letters turn red when exposed to it. (ACS Sensors 2025, DOI: 10.1021/acssensors.4c03737)
According to a study published in the scientific journal ACS Sensors, the tattoos were consistently able to detect small amounts of GHB — as little as 0.01 micrograms in 1 milliliter of liquid — in a variety of beverages, including whiskey, vodka, beer, coffee and soju (a popular Korean alcoholic drink).
The tattoos could also prove useful after an assault has occurred, the researchers say. Authorities often struggle to determine whether a victim consumed a “spiked” drink because common date-rape drugs stop being detectible in someone’s system within a few hours and often can only be verified by a professional lab. But the tattoos can display a positive result for up to 30 days, which the researchers say “could be important if it’s needed as a form of evidence of tampering.”
So far, the tattoos have only been tested with GHB, but the researchers say the same system could likely be used to detect other drugs if different chemical receptors are added.
It’s unclear when the tattoos might be available to the public, but the researchers said a commercial product could be on the market soon because the tattoos are inexpensive and easy to manufacture.
