The drugs are being sold as cough and cold medicines.
But in recent years, they have been used in a variety of other ways, from injecting them into patients to providing heroin as a substitute for morphine, which is more addictive.
Some of the biggest dangers are that they can make you drowsy, and the opioids can increase the risk of overdose.
In recent years the US has seen an explosion in overdoses involving opioids, which have caused about 6,300 deaths in 2016, according to the Centers for Disease Control and Prevention.
Some studies have shown that opioid use has a direct impact on how quickly someone is able to recover from a drug overdose, and some people do not recover at all.
While the US Centers for Medicare and Medicaid Services says that fentanyl is one of the most dangerous opioids, the risk for overdose is not as great.
Some people who overdose do not feel as well, and there is no clear way to prevent overdose.
But if you have a history of overdoses, there is some research suggesting that you may have a higher chance of dying from overdose than someone who did not use opioids.
The US Drug Enforcement Agency is also working to improve the safety of fentanyl.
The agency’s task force on fentanyl, which includes experts in pharmaceutical, biotechnology and medical devices, is set to publish its recommendations later this month.
There are several ways to reduce the risk.
If you are a medical professional who treats people with severe mental illness, or someone who is taking a prescription drug or is taking other medications that may interact with fentanyl, there are ways to minimize the risk, said Robert Kavcic, the DEA’s deputy administrator for the National Drug Control Strategy.
He added that you should talk to your doctor about how to manage the risks.
A good idea is to use the best mask and gloves, wear a mask if you use the cough or cold remedy, and avoid getting into the shower or hot tub.
The National Institute on Drug Abuse is advising people who are taking fentanyl to keep them out of direct sunlight, as well as in an enclosed area, and to avoid sitting on furniture or in a hot tub that might be heated or have a fan.
Some states have passed laws that make it harder to buy fentanyl from China or other suppliers, but some experts say there is a risk of people getting caught with fentanyl and potentially getting caught in a bigger crisis.
You can also buy it online, but there is more competition, and that is one reason why it is so hard to stop buying it, said Michael Pregent, a professor of pharmacy and an associate dean at the University of Southern California School of Pharmacy.
If someone is going to get caught and then be sentenced to prison, he said, they might try to get fentanyl from someone who already has it.
A US government study of fentanyl found that there was evidence of “significant overlap” between the two fentanyl strains, so it is likely that some people have been taking fentanyl together.
The problem is that fentanyl can be quite strong, and people have difficulty controlling how much they are taking.
In a few cases, fentanyl has caused death.
The FDA says that its task force has recommended that anyone taking fentanyl should have their blood pressure checked before they start taking it.
In some cases, people who do not have high blood pressure may be able to get around this by reducing their intake of alcohol, Pregents said.
Another way to reduce risk is to stop taking opioids.
Many people use them to treat conditions such as pain, anxiety and depression.
Some experts say that people who take opioids might not be at high risk for addiction.
But some experts also caution that opioid users may not be able or willing to cut back on the amount of opioids they are using.
Some opioid users say they have quit opioids, and have started to use more natural substances like tea.
There is evidence that people in their 20s, 30s and 40s are more likely to use opioids, so if you are in your 20s or 30s, and you are not at high levels, you may not need to take them as much, Pritchard said.
“I think we are probably getting close to the point where we can say, well, the best thing is to start to give up opioids,” Pregnant women, who are more prone to opioid use, are especially vulnerable to overdoses.
One of the things opioids do is increase the amount and severity of symptoms that can cause withdrawal symptoms.
Many opioids also can affect the nervous system.
So when someone takes opioids, they can have an effect on the nerves in the brain that can also affect how well they can function.
Pregented recommends that you talk to a doctor about the risks and benefits of opioids.
If opioids do not make you feel well, then you may need to stop.
That may mean talking to a friend, someone who understands you, or an addiction specialist, Prowse said.