that it has become a crisis in North and Shoth America.

Simply touching it may cause you to overdose,

so: What exactly does it do to your brain and body?

Fentanyl is an opioid that can inhibit pain signals in multiple pathways along the brain and spinal cord.

This is why it was initially prescribed for pain relief.

It also causes your brain to make More dopamine, creating sensations of intense euphoria and relaxation.

Essentially, fentanyl hijacks your body's built in system of endorphins,

by binding to your opioid receptors, much in the same way your endorphins do,

but at a significantly stronger level.

This might sound fun, but activating these receptors can also suppress your brains ability to

detect CO₂ levels in the body, potentially causing a person to stop breathing.

On top of this, side effects include dizziness,

chills, vomiting, fainting, difficulty urinating, and extreme constipation.

In addition, fentanyl is much stronger than other opioids,

100 times stronger than morphine, and 50 times stronger than heroin.

For many drugs to work, they need to pass the blood-brain barrier,

this barrier allows small, fat soluble substances to pass, and water-loving molecules to be inhibited.

Both morphine and heroin are lipid soluble, but have polar, water loving groups

that make them pass the barrier much more slowly,

where as fentanyl is extremely non-polar and fat soluble, entering the brain within seconds.

This means you only need tiny amounts to get high. And that's where, in part, the danger lies.

A lethal dose of fentanyl can be around two milligrams. In test tubes, that looks like two grains of salt.

And since a high level of precision is needed to dose it effectively, it's very easy to overdose.

In fact, there are some reported incidents of first responders ODing from simply touching fentanyl powder,

or inhaling its dust.

Though, some toxicologists doubt the accuracy of these cases.

If it can be administered in time, an injection of naloxone can be given to a person

which works to stop an overdose by blocking opioid receptors.

But the science cannot keep up with rate of new fentanyl analogues being produced.

Like carfentanil, which is 10000,000 times more powerful than morphine,

and has been cited in its possible use in chemical warfare.

Today, drug overdose deaths in America are rising faster than ever,

with 110,000 deaths in 2017, compared to 65,000 deaths in 2016,

and opioid use is the crux of the problem.

For context, this is than the peak gun deaths,

peak HIV deaths, and peak car crash deaths.

All evidence points toward the problem worsening by the end of 2018.

The reason? Research points to widespread prescription of opioids for pain, which leads to addiction.

There's also an ease of access for non-prescribers, causing millions of tablets to fall into the wrong hands.

As the danger became more clear, doctors decreased prescriptions of opioids,

but this didn't change the fact that thousands of people were addicted, causing them to seek out illegal markets.

With an increase in demand, illicit drug markets turned to cheaper production solutions.

Unlike heroin, which is synthesised from poppies, fentanyl is entirely synthetic and can be made anywhere for cheap.

China has become a super heavyweight in manufacturing fentanyl, and North American law is working to seize supply.

However, the UK urges that solutions to the crisis will lie in persuading people not to use opioids,

as blocking China's market may simply cause production to move to another nation.

Several experts are calling for government for safe consumption sites

where people suffering addiction can be supervised, minimising risk of overdose,

and can be supported with counselling and anti-withdrawal drugs, that can help people stop using.

But can some drugs be good for you?

Check out our first video here, where we look through the surprising benefits of some illegal drugs,

and what new research is unrevealed.

Check it out by clicking the screen or using the link in the description.

And subscribe for more weekly science videos every Wednesday