What Are Opioids?

Medically Reviewed by Minesh Khatri, MD on May 10, 2021

If you’ve just had surgery or a severe injury, or if you have chronic pain, your doctor may prescribe you opioids to lessen your discomfort. Pain-numbing medicines made from the opium poppy plant are called opiates. Man-made versions of these drugs are opioids, but that word often refers to all forms of opiates. Opioids and opiates work the same way.

Opioids are narcotics, which block feelings of pain. Milder forms of opioids also can help suppress coughs or ease severe diarrhea.

How Do You Take Them?

It depends on your situation. But there are several ways to get opioids:

  • Pill or liquid by mouth
  • Nasal spray
  • Skin patch
  • Tablet dissolved under the tongue or between the gum and cheek
  • Suppository
  • Shot into a vein
  • Shot into a muscle
  • Shot into the space surrounding the spinal cord
  • Implanted pump

Opioids can be short-acting or long-acting. The short-acting kind often have an opioid as the only pain medicine or a combination of an opioid and another type of pain reliever, such as acetaminophen or ibuprofen. It can take 15 to 30 minutes for you to feel relief, which should last for 3 to 4 hours.

They help with pain from serious injury or surgery, and they're usually prescribed for pain that lasts only a few days.

If you’ve had moderate to severe pain for a long time, your doctor can give you something with a longer-lasting effect. These can give you steady relief for 8 to 12 hours and are taken on a regular schedule.

You can also use short-acting opioids with a long-acting treatment as “rescue medication” for times when the pain is very bad.

How Do Opioids Work?

Opioids attach to receptors -- a part of cells -- found in the brain, spinal cord, and other areas of the body. They reduce the sending of pain messages to the brain and reduce feelings of pain.

What Opioids Are Available?

Examples of opioids are:

What Are the Side Effects?

Opioids can slow your breathing, and lower your heart rate and blood pressure, so talk to your doctor and make sure these medications are safe for you, especially if you’re taking other medications.

There are other side effects. You can ease most of them by adjusting the dose. Or talk to your doctor about trying other medications. Taking up healthy habits, like exercise and eating better, can help, too.

Be aware that some can affect your ability to drive.

Common side effects include:

What About Dependence and Tolerance?

It’s common to develop a dependence on certain medications if you use them for a long time. If you physically depend on a medication, you’ll have withdrawal symptoms if you stop using it.

Symptoms of opioid withdrawal include:

  • Restlessness
  • Muscle and bone pain
  • Insomnia
  • Diarrhea
  • Vomiting
  • Chills with goosebumps
  • Involuntary leg movements

Dependence often goes hand-in-hand with tolerance, which is the need to take higher doses of a medication to get the same effect. But higher doses often lead to more or dangerous side effects. Your doctor can change the opioid you take or add another kind of pain reliever to combat problems of tolerance. They can also add other methods to cut pain.

Do I Need to Worry About Addiction?

Don’t confuse tolerance and physical dependence with addiction, which is a brain disease marked by compulsive behavior. If you are addicted, you:

  • Can’t stop taking the drug
  • Feel anxious, moody, depressed, or uninterested in things
  • Spend all your money on drugs
  • Lie, hide, or steal because of drugs
  • Slur your speech or feel agitated
  • Neglect work, family, and your appearance

Dependence and tolerance are common among people who take opioids, but a person taking opioids can become physically dependent without being addicted. Learn more about the signs and symptoms of opioid addiction.

Between 8% and 12% of people who take opioids develop an opioid use disorder.

Opioids can give you much-needed relief, but there are risks and side effects. If you’re prescribed an opioid, make sure you stay in touch with your doctor while you take it so that you use it safely.

Show Sources


The National Alliance of Advocates for Buprenorphine Treatment: “Opiates/Opioids.”

American Chronic Pain Association: “Prescription Medications for Chronic Pain,” “Opioids.”

MedlinePlus: “Opioids and Chronic Pain.”

National Institute on Drug Abuse: “What Are Opioids?” "Opioid Overdose Crisis."

ACPA Resource Guide To Chronic Pain Medication & Treatment 2015 Edition, American Chronic Pain Association, 2015.

National Institutes of Health: “Complete biosynthesis of opioids in yeast.”

Narconon: “Signs and Symptoms of Prescription Pain Reliever Abuse.”

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