Learn / What Is Carfentanil?

What Is Carfentanil?

Grace Ogren
 September 20th, 2023|   Clinically Reviewed by 
Dr. Malasri Chaudhery-Malgeri, Ph.D.

Key Points

  • Carfentanil is a synthetic opioid similar to fentanyl.
  • It's 100x more potent than fentanyl.
  • Addiction treatment can help you heal from carfentanil use.

Carfentanil is a fentanyl analog, or a synthetic opioid chemically similar to fentanyl. It’s 100 times more potent than fentanyl and 10,000 times more potent than morphine. Because of that, carfentanil is considered the strongest and most dangerous fentanyl derivative

People usually take carfentanil by accident. But since you need so little (about one grain of salt) to overdose, these accidental uses can quickly become life-threatening. 

What Is Carfentanil Used For?

Carfentanil has only one approved use: a large-animal tranquilizer. The veterinary field uses carfentanil on elephants and other similarly sized animals; it’s not approved for human use in any way.

But in illicit drug markets, dealers use carfentanil to increase the potency of their drugs and sell them for more money. Additives like carfentanil make drugs like heroin feel stronger, leading to faster dependency and continued profit for the dealer. 

Carfentanil easily blends into other substances, so you never truly know if you’re taking a clean or laced substance. Even fentanyl test strips often don’t pick up on carfentanil. To the naked eye, carfentanil doesn’t stand out against the substance you think you’re taking—which is why it poses such a risk.

What Does Carfentanil Look Like?

Carfentanil looks white and powdery, like powdered sugar. If it’s been dissolved into a liquid, it can look as innocent as water. It may also look grainy, like salt grains. Carfentanil has no smell or taste

Dealers manipulate carfentanil to create new ways of ingestion. For example, you could take carfentanil as a pill, inject it intravenously, snort it as a powder, or place a small piece of carfentanil-soaked blotter paper on your tongue for a few minutes.  

Explore Synthetic Drugs Treatment Centers

What Are The Potential Effects of Using Carfentanil?

As a synthetic opioid, carfentanil’s effects mirror those of heroin, including:


Carfentanil is a mu-opioid receptor agonist, which means it triggers mu-opioid receptors to send a cascade of chemical signals in your brain. This ultimately releases dopamine, and lots of it. The flood of dopamine causes both euphoria and the need to repeat the behavior

Pain Relief

When used as prescribed, opioids work as powerful pain relievers. Carfentanil is no different. It calms the neurons in certain areas of the brain, leading to pain relief. But because of its potency, no amount of carfentanil has been approved for pain relief. 


Carfentanil can calm the brain and nervous system to the point of total sedation. That’s why veterinarians use carfentanil to sedate large animals. 


Carfentanil overdoses continue to rise in the US. Just two milligrams of carfentanil could kill you. Anything below that tiny amount would likely cause a non-lethal overdose. 

What Are The Symptoms of Carfentanil Overdose?

Overdosing on carfentanil causes a host of side effects. Even accidental exposure to carfentanil, like getting some of it on your hand or having the powder blow on your face, could cause an overdose. Knowing the signs of an overdose can help save lives. 

Blue Lips And Nails

Look at the nail beds and lips for blue coloration. Carfentanil overdoses can cause low blood pressure and a dangerously slow heart rate, which can lower breathing and oxygen intake. Less oxygen in the blood makes it look blue in areas like the lips and fingertips.

Choking And Gurgling

Overdosing on carfentanil can slow your breathing and dangerously sedate you. Because of this, you may choke on your spit or be too disoriented to remember to swallow it. That can cause choking and gurgly breathing, almost like snoring.

Pin-Point Pupils

A carfentanil overdose often causes tiny pupils. Someone who’s overdosed may have strangely small pupils that don’t dilate in different lighting.

Slowed Breathing

Your breathing may slow to null if you overdose on carfentanil. This can then lead to black outs, blue fingers and lips, and death.

Losing Consciousness

Overdosing on carfentanil could cause you to black out. The reasons for losing consciousness can include sedation/sleepiness, slow breathing, slowed heart rate, and a combination of all 3. 


Someone who overdosed on carfentanil may feel cold to the touch, shiver, and have a bluish tint. 

Clammy Skin

Carfentanil overdoses also cause clammy skin, or like someone’s slightly sweaty and cold at the same time. 

Heart Failure

Too much carfentanil could cause total heart failure. An overdose can depress your central nervous system enough to stop your heart. Without immediate help, this symptom often leads to death.

Can You Reverse a Carfentanil Overdose?

You can save someone who’s overdosed on carfentanil by immediately using Naloxone. If you administer it fast enough, you can reverse the effects of carfentanil and save their life. Since carfentanil is so potent, you’ll likely need several strong doses of Naloxone. You can inject it intravenously or, if your kit includes a nasal spray, squirt it up their nose.

 If you’re injecting Naloxone (Narcan), be sure to fill the syringe with liquid and not air. Then poke the needle into a large muscle, like a shoulder or thigh muscle. To administer the nasal spray, stick the nozzle into their nose and push up on the plunger. You’ll likely need to spray into each nostril. Narcan takes 2-3 minutes to show effects. 

Once stabilized and physically safe, treatment begins. 

Get Treatment for Opioid Use

Treatment for synthetic drugs like carfentanil includes medical and emotional care. You’ll begin with detox, which safely removes carfentanil from your body. Once carfentanil is out of your system, you and your treatment team will address the thoughts and behaviors leading to your drug use. Then, you’ll work together to learn new coping skills and navigate difficult emotions, cravings, and triggers as they come. 

Your treatment journey may begin in a residential rehab, where you’ll have 24/7 care, 1:1 and group therapies, and a safe space to detox. After residential treatment, you can move into day treatment or an intensive outpatient program, which provides intensive but more independent care.
To start your journey, you can browse our list of rehabs for opioid use to see pricing, photos, reviews, and more.

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