Dealing with a sudden back injury or a stiff neck can be incredibly painful, often making it difficult to perform basic daily activities like sitting, standing or getting a good night’s rest. When pain reaches this level of intensity, healthcare providers may prescribe muscle relaxers to help manage the discomfort and restore your mobility. These medications work by calming the sharp, involuntary muscle spasms that cause intense pain and “locking” sensations. By easing this tension, muscle relaxers can provide significant relief relatively quickly, helping you get back to your normal routine and allowing your body to focus on healing.
Despite their benefits, it is very common for people to feel cautious or even a bit nervous about starting this type of prescription. Much of this hesitation stems from valid concerns regarding safety or the potential for dependency often associated with stronger medications. It is completely natural to want to take care of your health, and understanding the role of these medications (usually intended for short-term use) can help you feel more confident in your recovery plan.
Overview
Yes, certain muscle relaxers can be highly addictive and carry a significant risk of physical dependence and abuse. However, not all muscle relaxers are the same. Medications like carisoprodol (Soma) and diazepam (Valium) are classified as controlled substances by the government because they have a very high potential for addiction, according to the National Center for Biotechnology Information.
Other common muscle relaxers, like cyclobenzaprine (Flexeril) or methocarbamol (Robaxin), are not classified as controlled substances and are generally considered less addictive. However, they can still cause physical dependence if taken for a long time. Because of these risks, muscle relaxers are typically intended for use for only two to three weeks to treat sudden, acute pain.
How muscle relaxers work
To understand how you can become addicted to these medications, you first have to understand how they work inside your body. The name “muscle relaxer” is actually a bit misleading. These pills do not travel directly to your sore lower back and fix the torn muscle.
Instead, they are central nervous system depressants. This means they travel to your brain and spinal cord, slowing communication between your brain and body. According to the Cleveland Clinic, muscle relaxers work by blocking pain signals traveling along your nerves and by acting as a sedative.
PubMed Central explains that by quieting the entire nervous system, they force your entire body to relax, which inadvertently stops the painful muscle from spasming. Because they alter your brain chemistry and create a generalized feeling of heavy relaxation and sedation, they can trigger the brain’s reward system, which is what leads to addiction.
Common side effects
Because these medications work by slowing your entire central nervous system, they can cause a wide range of side effects that affect your whole body, not just your sore muscles.
Drowsiness and dizziness
When taking muscle relaxants, the most common and significant side effect you’re likely to experience is profound drowsiness. Because these medications function as central nervous system depressants, they don’t just relax your muscles; they effectively “dial down” your entire level of alertness. This often manifests as an overwhelming sense of lethargy, where your limbs feel physically heavy, almost like lead, and your cognitive processing feels sluggish or foggy.
In addition to this intense fatigue, dizziness and loss of equilibrium are extremely common. You may experience a spinning sensation or significant unsteadiness, particularly when moving from a seated to a standing position. This lack of coordination makes everyday tasks surprisingly hazardous. Specifically, the combination of delayed reaction times and impaired motor skills makes driving a vehicle or operating heavy machinery incredibly dangerous.
Dry mouth and confusion
When taking muscle relaxants, the discomfort often extends beyond simple tiredness into a range of anticholinergic side effects. These occur because many muscle relaxers work by blocking acetylcholine, a key chemical messenger in the nervous system that regulates involuntary body functions. The result is often a sensation of being “dried out.” Severe dry mouth (xerostomia) is a hallmark symptom, which can make swallowing or speaking feel physically scratchy and difficult. This “drying” effect also impacts the digestive system and the eyes, frequently leading to persistent constipation and blurred vision, making it hard to focus on a screen or read a book.
The impact on the brain is equally significant. As noted by the American Addiction Centers, these medications can induce a pervasive state of “brain fog.” This isn’t just minor forgetfulness; it is a cognitive clouding that makes it difficult to follow complex instructions, retain new information or maintain the thread of a conversation. You might find yourself mid-sentence and completely lose your train of thought.
Rare or serious side effects
While common side effects are mostly just annoying, there are serious risks associated with taking these drugs, especially if you take more than the healthcare provider prescribes.
The most serious risk is severe respiratory depression. If you take too high a dose, the medication can slow your nervous system down so much that your body actually forgets to breathe. This risk skyrockets to life-threatening levels if you mix muscle relaxers with alcohol or opioid painkillers, explains the Cleveland Clinic.
Long-term use or abuse can also lead to liver damage and severe withdrawal symptoms, including hallucinations, tremors and seizures, if you try to stop taking the medication abruptly.
What to do if you notice symptoms
If you find that you are taking your muscle relaxer more often than prescribed, taking larger doses to get the same effect, or feeling panicked when you run out of pills, these are massive red flags for addiction.
You must contact your healthcare provider immediately. Do not try to quit taking the medication “cold turkey” on your own. According to Healthline, sudden withdrawal from central nervous system depressants can cause dangerous medical emergencies.
Your healthcare provider will help you create a tapering schedule that slowly and safely lowers your daily dose over several weeks, so your brain can adjust without going into shock. If you experience extreme shortness of breath, a racing heart or complete confusion, seek emergency medical care immediately, as these are signs of an overdose.
Alternatives to muscle relaxers
Because muscle relaxers come with the risk of addiction and only mask the pain instead of healing the injury, you should look into safer, long-term ways to heal your muscles. Over-the-counter pain relievers called NSAIDs (like ibuprofen or naproxen) are highly effective at reducing the deep tissue swelling that causes muscle spasms, notes Medline
Physical therapy is an incredible alternative. A trained physical therapist can teach you gentle stretching and strengthening exercises to heal the current injury and prevent it from ever coming back. Using a heating pad for 20 minutes to increase blood flow, followed by an ice pack to numb the pain, is another safe, natural way to force a spasming muscle to let go, according to PubMed Central.
You should absolutely never, under any circumstances, drink alcohol while taking a muscle relaxer. Both alcohol and muscle relaxers are central nervous system depressants. When you combine them, their effects multiply rapidly. This combination can cause you to pass out, severely lower your blood pressure, and cause your breathing to stop completely while you are asleep.
How do muscle relaxers make you feel the next day?
“Because these medications are strong sedatives with a relatively long half-life, their effects often linger long after you wake up, reminds Dr. Justus Rabach, MD. “Many people experience what is known as a ‘muscle relaxer hangover’ the very next day. You might wake up feeling incredibly groggy, confused and as though your limbs are made of lead.”
Even after a full night of sleep, you may find it very hard to focus on your morning tasks or keep your eyes open at work. This lingering brain fog is a major reason why many people prefer only to take these medications right before they go to bed.
Why don’t healthcare providers like to prescribe muscle relaxers?
Many healthcare providers are very hesitant to write a prescription for these pills, and for good reason. First, the Centers for Disease Control and Prevention (CDC) guidelines emphasize that there is very little scientific evidence to support the claim that muscle relaxers heal injuries faster than simple rest and physical therapy.
Second, the risk of abuse, addiction and dangerous drug interactions is too high. Healthcare providers know that if a patient mixes a muscle relaxer with a prescribed opioid painkiller or an anxiety medication, the combination can easily be fatal. Because the risks often outweigh the temporary benefits, healthcare providers prefer to use safer treatments like NSAIDs and physical therapy as their first line of defense against back pain.
Who cannot take muscle relaxers?
Older adults (people over the age of 65) should generally avoid muscle relaxants because severe dizziness and drowsiness can dramatically increase their risk of falling and breaking a bone, according to Mayo Clinic. Furthermore, older kidneys and livers cannot clear the drug out of the system quickly, leading to an accidental overdose.
People with a history of substance abuse or addiction should also avoid them due to the high risk of relapse. Finally, pregnant women and people with severe liver disease must speak to a specialist before taking these drugs, as the chemicals can harm the developing baby or overwhelm a damaged liver.
“It’s vital to understand the potential links between opioid exposures and common symptoms or comorbidities of cerebral palsy, particularly respiratory disorders, psychiatric disorders, bowel disorders and fall-related fractures,” says University of Michigan Health professor of physical medicine and rehabilitation, Mark Peterson, Ph.D., M.S., FACSM.
Bottom line
While highly effective at stopping sudden, severe pain, muscle relaxers work by depressing the central nervous system, which carries a significant risk of sedation, physical dependence and addiction. They are generally only safe when used for less than two to three weeks under strict medical supervision. To heal your injury safely and avoid the risk of addiction, it is best to transition quickly to physical therapy, safe anti-inflammatory medications and natural heat/cold therapies.
Frequently Asked Questions
How long should it take for a muscle relaxer to kick in?
Most oral muscle relaxers begin to take effect and make you feel sleepy or relaxed within 30 to 60 minutes after swallowing the pill.
Is it bad to take a muscle relaxer every day?
Yes, taking them every single day for more than two or three weeks is dangerous because it rapidly increases your risk of building a physical tolerance and dangerous addiction.
How many hours does a muscle relaxer stay in your system?
Depending on the specific type of medication and your liver function, the sedating effects usually last between four and six hours. Still, traces of the drug can remain in your body for several days.
Citations
Conermann T, Christian D. Carisoprodol. PubMed. Published 2022. https://www.ncbi.nlm.nih.gov/books/NBK553077/
Cleveland Clinic. Muscle Relaxers. Cleveland Clinic. Published February 7, 2023. https://my.clevelandclinic.org/health/treatments/24686-muscle-relaxers
Grabarczyk Ł, Wen-Tau H, Rymsza M, Stankiewicz A, Dhaif MDA, Szewczyk M. Skeletal Muscle Relaxants and Their Impact on Intracranial Pressure in Neurosurgery. Medical Science Monitor. 2024;30. doi:https://doi.org/10.12659/msm.946569
Kaliszewski M, October 23 PU, 2019. Side Effects of Muscle Relaxers – Treatment Options. American Addiction Centers. Published 2024. https://americanaddictioncenters.org/prescription-drugs/side-effects-of-muscle-relaxers
Cleveland Clinic. Respiratory Depression (Hypoventilation). Cleveland Clinic. Published November 7, 2023. https://my.clevelandclinic.org/health/diseases/respiratory-depression
Holland K. The Dangers of Abruptly Stopping Antidepressants. Healthline. Published May 14, 2015. https://www.healthline.com/health/depression/dangers-of-stopping-antidepressants
Medline Plus. Over-the-counter pain relievers: MedlinePlus Medical Encyclopedia. medlineplus.gov. Published 2024. https://medlineplus.gov/ency/article/002123.htm
Freiwald J, Magni A, Fanlo-Mazas P, et al. A role for superficial heat therapy in the management of non-specific, mild-to-moderate low back pain in current clinical practice: A narrative review. Life. 2021;11(8):780. doi:https://doi.org/10.3390/life11080780
Dowell D, Ragan K, Jones C, Baldwin G, Chou R. CDC Clinical Practice Guideline for Prescribing Opioids for Pain. MMWR Recommendations and Reports. 2022;71(3):1-95. doi:https://doi.org/10.15585/mmwr.rr7103a1
Mayo Clinic. Medicines that increase fall risk in older adults. Mayo Clinic. Published 2024. https://www.mayoclinic.org/healthy-lifestyle/healthy-aging/in-depth/fall-risk/art-20572713