Evidence based

Flexeril: Narcotic or Not?

Last updated: 
November 4, 2019
Abby Perry
Researcher and author
Dr. Juliana Bruner, DPT
Researcher and author, Physical Therapist

If you’re experienced severe musculoskeletal pain that hasn’t responded to physical therapy and over-the-counter medications, your doctor may consider prescribing stronger drugs. Muscle relaxants are one such class of second-line pain medications that are particularly useful for acute pain. Your doctor may choose to speak to you about Flexeril, a commonly used muscle relaxant in cases of persistent pain.

But how do you know if Flexeril is safe for you? Does it carry especially serious side effects? In this article, we’ll explain what Flexeril is and discuss when it’s effective. We’ll also share the potential risks and side effects of using Flexeril so that you can make an informed choice about how to manage your pain.

What is Flexeril?

Flexeril is the brand name for a muscle relaxant called cyclobenzaprine (1). Other brands of cyclobenzaprine include Fexmid, FusePaq Tabradol, and Amrix (an extended-release capsule). Cyclobenzaprine relaxes muscles by reducing muscle spasms.

Cyclobenzaprine shares chemical similarities to tricyclic antidepressants, which are also sometimes prescribed to address muscle pain (2). It works by inhibiting serotonin transmission at the spinal cord (3). Serotonin is a neurotransmitter chemical that helps carry pain signals to the brain (4). By preventing serotonin transmission, cyclobenzaprine alleviates pain by reducing the number of pain signals that reach the central nervous system.

Cyclobenzaprine is most useful for cases of acute musculoskeletal pain and muscle spasms. It can be used on occasion for chronic pain, though it’s less suited for this kind of pain (5). Cyclobenzaprine is effective for relieving lower back and neck pain (6, 7). Patients who suffer from fibromyalgia may find that cyclobenzaprine both relaxes their aching muscles and helps improve their sleep (8).


Cyclobenzaprine is a prescription drug commonly sold in the US as Flexeril. It is most useful in cases of acute musculoskeletal pain and muscle spasms. It’s also be effective in treating low back pain, neck pain, and fibromyalgia.

Is Cyclobenzaprine a Narcotic?

In a word, no. Cyclobenzaprine is not a narcotic or an opioid. Unlike a handful of other muscle relaxers such as carisoprodol (Soma), it’s not currently controlled under the Controlled Substances Act (9).


Cyclobenzaprine – including Flexeril and Amrixz – is not a narcotic drug or scheduled by the Drug Enforcement Agency.

What Are the Risks of Cyclobenzaprine – Could I Become Addicted?


The primary adverse side effects of cyclobenzaprine are related to the central nervous system (CNS), and include drowsiness, dizziness, and nervousness (10). Some patients also report gastrointestinal issues (stomach problems) like nausea, vomiting, constipation, and loss of appetite, as well as dry mouth (11, 12).

Cyclobenzaprine carries greater risks for elderly patients (13). This is possibly due to the absorption pattern of cyclobenzaprine, meaning that extended release cyclobenzaprine capsules may pose particular risks to the elderly (14).

Drug Abuse

Because it’s generally prescribed as a short-term response to acute pain, Flexeril abuse is rather unlikely. However, cyclobenzaprine and other muscle relaxants can be abused if they’re taken in excessive doses, so patients should be careful to adhere to their doctor’s instructions. Signs of Flexeril overdose include agitation, trouble speaking or moving, and hallucinations (15).

Cyclobenzaprine will amplify the effects of alcohol and other CNS depressants. The Mayo Clinic recommends that you speak to your doctor about the potential dangers of taking cyclobenzaprine if you’re currently taking any of the following central nervous system depressants (16):

  • Antihistamines
  • Medicine for hay fever, allergies, or colds
  • Sedatives
  • Tranquilizers
  • Sleeping medicine
  • Prescription pain medicine
  • Narcotics
  • Medicine for seizures
  • Barbiturates
  • Other muscle relaxants
  • Anesthetics (including dental anesthetics)

You should try to avoid cyclobenzaprine if you suffer from overactive thyroid, have had heart failure, irregular heartbeat, or have used monoamine oxidase inhibitors (MAO inhibitor) antidepressants like selegiline (Emsam) or phenelzine (Nardil) in the past two weeks. Overall, however, the literature shows that cyclobenzaprine is likely safer than other muscle relaxants such as carisoprodol, as well as some antidepressants (17).


Common side effects of cyclobenzaprine include drowsiness and dizziness. While drug interactions mean Flexeril should be avoided for some, and Flexeril abuse is possible, it’s generally safe when taken according to the United States Food and Drug Administration (FDA) dosage.

What Can I Do If Flexeril Doesn’t Help My Pain?

If cyclobenzaprine isn’t effectively treating your pain, don’t give up on finding relief. There are several other options you can try to address your pain.


For pain that becomes chronic and doesn’t respond to cyclobenzaprine, antidepressants may be useful (these can be used to treat musculoskeletal pain). The Mayo Clinic lists the following conditions that antidepressants can treat effectively (18):

  • Arthritis
  • Nerve damage from diabetes (diabetic neuropathy)
  • Nerve damage from shingles (postherpetic neuralgia)
  • Nerve pain from other causes (peripheral neuropathy, spinal cord injury, stroke, radiculopathy)
  • Tension headache
  • Migraine
  • Facial pain
  • Fibromyalgia
  • Low back pain
  • Pelvic pain
  • Pain due to multiple sclerosis

If your doctor prescribes an antidepressant for your pain, give it a try for several weeks. The drug will need to build up in your system in order to have maximum effect. If an antidepressant helps to some degree but you still have pain, talk to a healthcare provider about incorporating a medication from another drug class into your treatment plan.

A few types of antidepressants can be used for nerve pain, including tricyclic antidepressants, which include Amitriptyline (Elavil), Doxepin (Sinequan), and Nortriptyline (Pamelor). Serotonin-norepinephrine reuptake inhibitors (SNRIs) such as duloxetine (Cymbalta) and venlafaxine (Effexor) can also be used for pain, as can selective serotonin reuptake inhibitors (SSRIs) like fluoxetine (Prozac) (19).

Side effects of tricyclic antidepressants include drowsiness, blurred vision, and drop in blood pressure when standing up after sitting (20). Some patients taking SNRIs report nausea, dizziness, and dizziness (21). Many side effects of SSRIs stop after a few weeks of taking the medication, but if nausea, headache, insomnia, or agitation last for several weeks or becoming intolerable, talk to your healthcare provider about trying another medication (22). Both SSRIs and SNRIS may be linked to serotonin syndrome (23).

At-home Remedies

There are several pain relief remedies that you can purchase over-the-counter or online. While they may not provide the long-term relief you need, sometimes at-home can help you manage your pain as you find a long-term treatment option. Some helpful at-home remedies for musculoskeletal pain include:

  • Cold therapy (cryotherapy): Many people who suffer from muscle and joint pain, including athletes, find relief from applying cold materials to the affected area. When combined with rest, ice packs, cooling sprays, and even bags of frozen peas can numb the painful area and reduce swelling. If you’d like to try cold therapy, wrap the cold object in a towel to reduce the likelihood of irritating your skin. Then apply the wrapped object to the painful joint or muscle for 10 to 20 minutes (24).
  • Heat therapy: You may find that applied heat for 10 to 20 minutes reduces your pain. Heat therapy increases pain tolerance and relaxes muscles. Consider taking a hot bath or shower—dress warmth afterward to prolong the effect. Heating pads, heat patches, and paraffin wraps can also help with pain (25).
  • Over-the-counter medications: Non-steroidal anti-inflammatory drugs can effectively relieve many kinds of pain. Ibuprofen (Advil), Naproxen (Aleve), and Aspirin can all be purchased at your local pharmacy or on the internet. Acetaminophen (Tylenol) can also be purchased over-the-counter and reduces pain and fever but is not anti-inflammatory. Side effects of NSAIDs include gastrointestinal problems (stomach pain) and cardiovascular problems  (heart issues). Acetaminophen can cause liver damage when taken in large quantities or with alcohol. Talk to your doctor about any concerns you have regarding over-the-counter medications based on your personal clinical history or family health history. 

Manual Therapies 

Physical therapy can help with back pain, knee pain, and neck pain. Especially in the case of back pain, physical therapy is an effective first-line treatment. Physical therapists combine stretches and exercises to strengthen muscles and relieve pressure from joints.

Chiropractic care, another form of manual therapy, aligns the spine through spinal manipulation. It demonstrates similar therapeutic effects to physical therapy for neck pain (26). However, physical therapy tends to outperform chiropractic care in the cases of back pain and knee pain.

Both physical therapy and chiropractic care will achieve maximum positive results when patients attend appointments regularly for a period of time. It’s common in both cases for the practitioner to recommend three appointments per week for 4 - 6 weeks. Before you schedule an appointment with a physical therapist or chiropractor to design a treatment plan, look into the following factors:

  • How far away is the office from your home or workplace?
  • Do the office hours work with your schedule?
  • Does your insurance provider cover your preferred practitioner?
  • How comfortable are you with the practitioner—can you be honest about your pain level? Are you comfortable with them touching you? 

Asking questions like these can help you follow through on a treatment plan with a physical therapist or chiropractor so that you can achieve the best results possible for pain relief.

Injections and Surgery

Some cases of severe pain may require injections or surgery. Steroid injections may effectively treat nerve-related back pain temporarily. Cortisone shots may relieve pain resulting from inflamed joints or tissues, but they do not heal injuries or prevent future issues. If your healthcare provider determines that steroid injections could be an effective part of your treatment plan, they may recommend injections in one of the following target areas:

  • Epidural space near the nerve roots, which can be the source of sciatica and low back pain.
  • Tendons and bursae, which provide cushion between muscles and tensions in order to reduce friction during movement.
  • Joints that are inflamed, such has inflamed knee joints resulting from arthritis (27).

Anesthetic injections, such as cervical epidural injections, may be necessary in cases of disc herniation and associated neck issues (28). Heat-based injections called radiofrequency denervation (RFD), can offer short-term relief for chronic neck pain, but more research is needed to substantiate the effects of RFD injections (29). The most severe cases of pain may require surgery.

The side effects of injections include a temporary increase in pain in response to the injections and skin irritations (30). Surgery carries a risk of reaction to anesthesia and infection. If you are considering injections or surgery as responses to your pain, have a thorough conversation with your healthcare provider about the effects. Considering asking questions like:

  • What are the remaining conservative treatment options I can try? 
  • What are the specific side effects I may be likely to experience based on my personal clinical history and family medical history?
  • If I decide to try injections, how many appointments should I expect to have before I notice pain relief? 
  • If steroid injections don’t work for me, could I try anesthesia or RFD injections?
  • What are the interactions of the current medications I take with injections or medications that would be required during or after surgery? 
  • How long is the recovery time for the surgery most likely to help relieve my pain? 
  • What are the home remedies I can try in order to maximize the effects of injections or surgery? 

Take your time talking with your doctor about your options and listening to their medical advice. Make sure you feel comfortable with your doctor’s approach and treatment plan. In the case of nerve and muscular problems, anxiety and tension can often increase the pain you’re experiencing. So ask the questions you need to ask and collect the information that’s important to you so that you can feel as relaxed as possible in your doctor’s care.


Some antidepressants can effectively treat pain. At-home remedies like cold and heat therapy, and manual therapies like physical therapy and chiropractic care may have therapeutic effects for pain. Steroid, anesthetic, or radiofrequency denervation injections may be necessary to combat some forms of pain and inflammation. In the most severe cases, surgery may be required.

What Do I Need to Remember?

Cyclobenzaprine is not a narcotic or an opioid, and is not scheduled by the DEA. That being said, dependency can develop if directions and dosage aren’t followed, so be careful to use this drug only as directed by your doctor.

The information provided in this article is not a substitute for professional medical advice, diagnosis, or treatment. You should not rely upon the content provided in this article for specific medical advice. If you have any questions or concerns, please talk to your doctor.

Research Citations

Researched, written, and reviewed by:
Abby Perry
Researcher and author
Abby Perry is a freelance writer who brings over ten years of experience with work published in Entropy, Fathom Magazine, and Sojourners. She lives in the great state of Texas with her husband and two sons.
Read full bio
Dr. Juliana Bruner, DPT
Researcher and author, Physical Therapist
Dr. Bruner is a physical therapist who is highly trained and skilled in helping people overcome their physical ailments to live the best life they can. She is also a writer who enjoys spreading knowledge about various topics in the PT and healthcare industry.
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This article is based on scientific evidence, written by experts and fact checked by experts.

Our team of board-certified physical therapists, physicians, and surgeons strive to be objective, unbiased, honest and to present both sides of the argument.

This article contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.