People looking to get away from it all this holiday should be careful about what they pack in their carry-on luggage before boarding a plane.
In addition to shoes, books, and toothpaste, you probably also store any medications you take—and while you might not think twice about packing doctor-prescribed medications, those everyday pills may be illegal at your destination.
Prescription drug regulations vary by country, and some medications that are readily available in some countries may be illegal in others, from cannabis, which is legal in some U.S. states, to painkillers such as Vicodin.
Researchers found that the United States has the strictest prescription drug laws when it comes to traveling with medications. The US bans 562 medications for travelers visiting the country.
Germany had the second strictest legislation on prescription drugs, with a list of 464 drugs illegal in the country.
With 328 banned drugs, Japan had the third strictest medication regulations and Colombia came in fourth, with 324 banned drugs.
The drugs most likely to get travelers into trouble included amphetamines – such as Adderall – and painkillers containing hydrocodone.
The list above shows the countries with the most controlled drugs on their banned list. The list was compiled by researchers at Universal Drugstore
Gigi Hadid at a Miu Miu event in California in August, following her marijuana arrest in the Cayman Islands a month earlier
Many countries have stricter restrictions on some medications due to concerns about addiction and its health effects.
Pharmacists from Universal Drugstore, who conducted the survey, urged Americans to check regulations in their destination country before traveling.
Some countries – such as Japan – allow travelers to enter with a prescription drug from their home country if they have a note from their doctor and only a 30-day supply.
But in other countries, passengers can be arrested at the border, face fines of more than $30,000 and up to 25 years in prison.
For their study, the researchers counted the number of controlled drugs that were banned in 18 countries.
They collected the data from official lists of banned substances, published by the countries' drug authorities or ministries of health.
The results showed that the United States had the strictest regulations.
This is likely due to the country's war on drugs, although limited enforcement in some areas means drugs are widely available.
In fifth place was the United Arab Emirates (UAE), with 293 banned controlled drugs, while Qatar was sixth, with 231 banned, and seventh was Thailand, with 225 banned.
Several celebrities have recently broken regulations in countries for transporting cannabis outside the US.
Supermodel Gigi Hadid was arrested at a Cayman Islands airport this year after she was found with marijuana – which she claimed she bought in New York City with a medical license.
The above shows the drugs most likely to be banned in the eighteen countries on the list, based on the percentage that banned the drug (the percentage).
The United States, Germany and Japan had the most banned controlled drugs
Amphetamines such as Adderall are used in the US to treat conditions such as ADHD (Attention Deficit Hyperactive Disorder), where the drugs improve concentration.
But many other countries – including Japan, the UAE and South Korea – have banned them due to the risks of addiction and abuse.
Hydrocodone with acetaminophen – also called Vicodin, Lortab, or Lorcet – is an opioid medication prescribed in the US for relieving moderate to severe pain.
It is one of the most popular drugs in America, with more than 83 million doses sold annually, but hydrocodone has been banned in many countries due to concerns about addiction.
Marijuana is illegal in more than 160 countries around the world – including Britain, Germany and Japan – and remains illegal at the federal level in the US.
America is going through a period of relaxing regulations — with 24 of the 50 states legalizing recreational marijuana — saying the drug can help people manage chronic pain and nausea and help with other conditions.
But the cannabis available today is much stronger than that of fifty years ago, and there are now concerns about the impact this is having on people's health.
A growing body of research shows that regular marijuana use can hinder brain development in young adults, while the drug has also been linked to hallucinations and psychosis.
Most countries have not legalized marijuana because of the potential risks it poses to people's health and because authorities there are not convinced the drug is safe.
When people enter the US with illegal drugs, they are stopped at customs. Penalties include fines and possible prison sentences.
Jamie Winn PharmD, Medical Director of Universal Drugstore, said: 'Traveling with prescription medications requires a good level of research into the legal drug laws in your host country, and you must understand your destination's medication regulations.
“If your prescription contains controlled substances, use extra caution.
'Always keep a copy of your prescription with you, which clearly states your medical condition and the need for the prescribed medications.
'Also familiarize yourself with the generic names of your medications, as brand names can vary worldwide.
'Make sure you stay informed if regulations change; therefore, you should check for updates from reliable government sources.”