Muscle relaxant (medicine, natural): does it give you sleep? How does it work?

When that back pain hits after a long day or after training at the gym, many people turn to muscle relaxants to get rid of that discomfort.

The problem, however, is that there are risks associated with the continuous use of this medication, which can even have an addictive potential, that is, addictive.

Learn more about muscle relaxants in the text below!


What is muscle relaxant?

Muscle relaxants are drugs used to prevent and reduce spasms, muscle contractions and spasticity .

Spasms occur when there is an involuntary contraction of a group of muscles. At that point, the muscles usually contract suddenly, causing pain.

Spasticity, on the other hand, occurs when some muscles contract firmly, becoming rigid and more difficult to move.

These drugs can also be used for other conditions, such as treating anxiety or difficulty sleeping ( insomnia ).

They can also be used as a pre-medication before surgery, especially in operations that cause anxiety or discomfort.

In addition, they are useful for treating seizures , as they can come in presentations that are easy to administer and have a quick effect.

Most muscle relaxants are available in tablets, capsules or drops. Some drugs administered via injection during surgery are also known as muscle relaxants.

In this case, they may be called “neuromuscular blockers” and are used to relax muscles during a surgical procedure. However, these are completely different medications from the most common muscle relaxants.

Muscle spasms versus spasticity

The muscle spasms are nothing more than involuntary muscle contractions that cause pain and stiffness located.

They are a protective mechanism of the muscle and occur in response to injury, inflammation or stretching, and can last from seconds to several minutes.

Spasticity, in turn, is a disorder of muscle control that leaves the muscles tense or rigid, unable to be controlled. In addition, the reflexes can remain for a long time and be very strong, causing a lot of pain and discomfort.

It is usually the result of an imbalance of signals from the central nervous system to the muscles.

Some of the conditions that can cause spasticity are brain damage, stroke, multiple sclerosis, amyotrophic lateral sclerosis (ALS) and other diseases.

What is the difference between muscle relaxant and anti-inflammatory?

The difference between the two drugs lies in the purpose with which they are used and their effects on the body.

While muscle relaxants seek to combat the pain caused by injuries, sprains or diseases, such as multiple sclerosis, the anti-inflammatory serves, as the name already says, to fight tissue inflammation.

Anti-inflammatory drugs, in general, aim to reduce the swelling and pain that appear in an inflamed organ or tissue in the body.

In inflammation of the throat, for example, the swelling is not visible, but it is noticeable by changes in the voice (which may even disappear) and by discomfort.

Neither drug is intended to fight infections. These roles are protected against antibiotics and antivirals. They have in common the fact that they fight pain, but the mechanisms of action are quite different.

While most muscle relaxants act directly on the Central Nervous System (CNS), anti-inflammatory drugs act locally, in the body’s tissues, preventing inflammation from happening.

Even so, many muscle relaxants have anti-inflammatory drugs in their formulas , because the anti-inflammatory action potentiates the effect of the medication, bringing more relief to the patient.

What is the muscle relaxant for?

Muscle relaxant is a medication that aims to quickly relieve muscle pain caused by sprains or diseases, such as fibromyalgia . These medications make the muscles less tense or stiff, which reduces feelings of pain and discomfort.

They can be used to treat:

  • Low back pain (common pain in the lower spine, known as low back pain);
  • Torticollis (condition in which the neck muscles contract painfully);
  • Fibromyalgia (disease that causes pain and generalized weakness);
  • Scapuloumeral periarthritis (pain and limitation of shoulder movements);
  • Cervicobraquialgia (pain in the cervical region that radiates to the arm);
  • Chronic pain;
  • Multiple sclerosis (neurological disease in which the immune system destroys the protective covering of neurons);
  • Chronic myelopathy (nervous system disorder);
  • Cerebrovascular accidents;
  • Cerebral palsy;
  • Intractable hiccup.

How do they act in the organism?

There are, in general, 2 types of muscle relaxants. While some medications act on the brain and spinal cord, others act directly on the muscle.

The ones that work in the Central Nervous System (CNS) are the Muscular Relaxers of Central Action , while those that work directly in the musculature are called Neuromuscular Blockers . Understand:

Centrally acting muscle relaxants (antispasmodics)

Centrally acting muscle relaxants act mainly on the Central Nervous System, relieving painful muscle spasms and the spasticity that occurs in musculoskeletal or neuromuscular disorders, such as bursitis, arthritis and fibromyalgia.

Muscle spasms can be defined as involuntary contractions of the muscles and are a protective mechanism of the muscle after injury, inflammation or stretching in the muscle itself or in nearby tissues such as bones and ligaments.

The exact mechanism of action of these drugs is not yet fully understood, but the most accepted hypotheses point to the CNS depressant activity of these drugs as the main facilitator of muscle relaxing effects.

In general, we can say that these drugs work within the body, reducing muscle tension, reducing spasms and, consequently, pain.

Once these substances enter the body, especially those that contain the active ingredient carisoprodol, they produce another substance called meprobamate, which acts as a tranquilizer.

Despite being part of the functioning of these drugs, it is possible that precisely because of this mechanism, patients develop addiction (addiction) to these substances, as the drug makes them more relaxed.

Centrally acting relaxants are usually those most easily found in pharmacies and have a more popular use, without the need for a prescription to purchase them.

Some of the main drugs that are in this category are:

  • Dorflex;
  • Tandrilax;
  • Trilax;
  • Coltrax;
  • Mirtax;
  • Torsilax.

Neuromuscular blockers

Neuromuscular blockers are drugs that interrupt the transmission of nerve impulse at the neuromuscular junction .

They are mostly used in surgeries, when the patient needs general anesthesia.

They are also useful in electroconvulsive therapy (passing an electric current through the body to treat psychiatric conditions such as depression ) to prevent trauma and fractures, as the seizures caused on purpose in this treatment can lead to these problems.

Explaining the action of this medicine in a simpler way, what happens is that these substances prevent the nerves from communicating with the muscles, which, in turn, temporarily prevents the transmission of pain signals.

The preference of these drugs in surgical situations is mainly because they provide adequate relaxation of the muscles of the abdomen and diaphragm. In addition, they relax the vocal cords, which facilitates the work of doctors if the patient needs to be intubated.

For this reason, they are not easily found in pharmacies and have a more restricted use.

Names of remedies with muscle relaxing action

There are several muscle relaxant medications. We will divide them below from the active principle:

Carisoprodol + Phenylbutazone + Paracetamol

The medicine with this active ingredient receives the commercial name of mioflex and is indicated for pain relief, inflammation and for the relaxation of the skeletal muscles.

It is also useful in the treatment of ankylosing spondylitis , rheumatoid arthritis , osteoarthritis and acute forms of extra-articular rheumatism in adults.

Carisoprodol + Diclofenac sodium + Caffeine + Paracetamol

The combination Carisoprodol and diclofenac sodium is indicated for the treatment of rheumatism and associated problems, such as low back pain , osteoarthritis, acute crisis of rheumatoid arthritis etc.

It is also indicated for the treatment of severe inflammation, such as after accidents or after surgery.

The main trade names for this active ingredient are:

  • Tandrilax ;
  • Trilax ;
  • Beserol ;
  • Infralax ;
  • Torsilax .

Cyclobenzaprine hydrochloride

Cyclobenzaprine hydrochloride is indicated for the treatment of muscle spasms with acute pain, such as lumbago, torticollis, fibromyalgia, scapuloumeral periarthritis (shoulder movement changes and limitations) and in the treatment of cervicobraquialgias (pains in the cervical region that radiate to the upper limbs ).

It can also serve as an adjunct medication to other measures for symptom relief, such as physiotherapy and rest.

It can be found in pharmacies with the following trade names:

  • Miosan ;
  • Musculare ;
  • Benziflex ;
  • Cizax ;
  • Mirtax .

Dipyrone monohydrate + Orphenadrine citrate + Caffeine

This active ingredient is indicated for the relief of pain caused by muscular contractures and tension headaches in adults.

It can also be used in the form of an adhesive to treat pain and localized inflammation.

It can be found in pharmacies with the following trade names:

  • Bioflex ;
  • Dorflex ;
  • Ana-flex .


Diazepam is an active ingredient belonging to the benzodiazepine class and has anxiolytic (to reduce anxiety), sedative (relaxation and sleep), anticonvulsant, amnesic (temporary memory loss) and muscle relaxant properties.

Precisely for this reason, this medication is more used for the symptomatic relief of psychiatric disorders such as anxiety, in addition to serving as an adjunct to the treatment of other psychiatric disorders.

However, this medication is also very useful for the relief of muscle spasm, and it can be used very punctually in the treatment of spasticity due to injuries, such as cerebral palsy and paraplegia.

Diazepam-based drugs are controlled, that is, they can only be sold with a prescription, only being indicated only for the treatment of severe, disabling disorders or for cases of extreme pain .

The main trade names for this active ingredient are:

  • Repalax ;
  • Compaz ;
  • Valium ;
  • Somaplus;
  • Diazefast;
  • Dienzepax ;
  • Kiatrium ;
  • Santiazepam ;
  • Uni Diazepax ;
  • Calmocytene ;
  • Dienpax .


Cannabidiol is a medication used to relieve muscle stiffness associated with multiple sclerosis. In Brazil, it is possible to find this medicine by the name Metavyl .

Child muscle relaxant

There is no muscle relaxant specifically aimed at children.

Except in cases of rare exception, it does not make much sense for children to use this type of medication, as their muscles are still developing and they do not suffer as much muscle pain as adults.

In case the child needs to take a muscle relaxant, it will always be necessary to adjust the dose, as his body is smaller, as well as his body mass. So, giving a normal dose could have unwanted effects, in addition to being quite dangerous.

Therefore, never give your child muscle relaxants without first consulting a pediatrician and checking whether or not there is a need to use this type of medication.

How to take?

Muscle relaxants are remedies that can have several side effects and should only be taken when prescribed by a doctor.

Although many do not need a prescription, these drugs should not be taken without the knowledge of a health professional, as chronic use can bring risks.

Ideally, this class of drugs will only be prescribed when acute and non-chronic pain occurs.

They can be an option if pain is disturbing sleep, as some of them induce drowsiness and can help patients sleep.

In general, the recommendation for adults and children over 12 years of age is to take a maximum of 1 tablet, pill or capsule every 6 hours. If the symptoms persist for more than 5 days, it is necessary to consult a doctor.

In the case of medications in drops it is necessary to take 30 to 60 drops 3 to 4 times a day orally. Exceeding this maximum drop limit (60) is dangerous and should never be done.

However, there are many variables in this process and it is not possible to recommend a specific dose for everyone. Patients with higher body mass may need higher doses, as well as the other way around.

For this reason, never take this medicine without your doctor’s knowledge .

Side effects

The use of muscle relaxants can also have some side effects. Check out the main ones:


Since muscle relaxants have an effect on the entire body, they usually cause drowsiness. Thus, it is not safe to drive or make important decisions while taking muscle relaxants.

The ideal is to take these drugs at night precisely because of this sedative effect.

Dry mouth

Dry mouth occurs when the salivary glands do not produce enough saliva. The use of various medications has the side effect of this symptom, which usually disappears after the medication stops taking effect.


Because of the relaxing effect that these medications promote, many patients may experience dizziness and vertigo, which is a sensation of movement or rotation of the body or its surroundings.


It is not uncommon for the use of muscle relaxants to leave the patient feeling fatigued . The patient feels weakened, worn out and lacking in energy.

Liver changes

Many of the muscle relaxants contain small doses of acetaminophen. This anti-inflammatory, in particular, can cause damage to health and cause liver damage.

Colic, nausea and vomiting

A considerable part of the medications can have as a side effect the appearance of cramps, nausea and vomiting. This is especially true for those oral medications, which are absorbed by the stomach and intestine.

Upon entering the digestive system, the presence of the drug can cause irritation in these organs, leading to these symptoms.

Changes in heart rate and blood pressure

The heart is a muscular organ of involuntary movement. When taking a muscle relaxant, it can have effects on the functioning of that organ and the entire cardiovascular system.

If, due to the medication, the heart beats with more or less intensity, blood pressure may change, as well as the heart rate itself.

Read more: Cardiac Arrhythmia: what is it, symptoms, treatment, is it curable?

Therefore, it is important to emphasize again that before taking this type of medication it is necessary to talk to a doctor or specialist.

Side effects of diazepam

The most common side effects of using diazepam are tiredness , drowsiness and muscle relaxation. They are felt especially at the beginning of the treatment.

These symptoms usually disappear after a longer administration.

Still, diazepam can have other adverse reactions, leading to disorders of the nervous system, such as ataxia (imbalance), difficulty in speaking, slurred speech, headache , tremors and dizziness .

In addition, anterograde amnesia (forgetting facts from the beginning of taking the medication) and other amnesic effects (from memory loss) can occur.

It can also generate paradoxical reactions, such as restlessness, agitation, irritability, aggression, delusions, anger , nightmares, hallucinations, psychosis and abnormal behavior. When these effects occur, the use of the drug should be discontinued.

It is a medication whose chronic use can cause physical dependence even in therapeutic doses. Hence the need for revenue retention.

Other side effects of using diazepam can be:

  • Nausea;
  • Dry mouth or hypersalivation;
  • Cold;
  • Diplopia;
  • Blurred vision;
  • Hypotension (low blood pressure);
  • Circulatory depression;
  • Irregular heart rate;
  • Urinary incontinence or retention;
  • Vertigo;
  • Heart failure, including cardiac arrest;
  • Respiratory depression, including respiratory failure;
  • Jaundice (very rarely).

Cannabidiol side effects

Cannabidiol is an extract taken from the leaf of marijuana and its use can bring some side effects.

Among them are dizziness, drowsiness, excitement, loss of memory, difficulty concentrating, blurred vision, difficulty in speaking, increased or loss of appetite, dry mouth, constipation or diarrhea , nausea or vomiting, feeling of intoxication or hallucinations.

It can also cause the appearance of sores in the mouth accompanied by a burning sensation or pain.


There are some risks related to the use of muscle relaxants. They can cause allergic reactions and even addiction. Understand:


Unfortunately, the use of muscle relaxants has additive potential for some people, meaning it can be addictive.

Taking these drugs without the express recommendation of a doctor or taking more than the doctor has recommended can increase the chances of addiction to these substances, as well as using them for an extended period.

Almost all cases of addiction and abuse of this type of substance occur with the active ingredient carisoprodol, found in relaxants such as Infralax, Trilax, Torsilax and Tandrilax.

Addiction happens because this active ingredient, once inside the body, produces a substance called meprobamate, which acts as a tranquilizer. That way, people can become addicted to carisoprodol because this drug makes them more relaxed.

Still, other types of muscle relaxants are also at risk of leading to addiction. Cyclobenzaprine, found in medications like Benziflex and Cizax, has also been reported as a substance of abuse.

The big problem is that the prolonged use of these substances can leave the patient physically dependent on these drugs. This means that, without medication, the patient may experience withdrawal symptoms, such as insomnia, anxiety and vomiting.

In the United States, another class of drugs has been causing problems for public health: opioids.

With a function similar to that of muscle relaxants (to relieve pain), these drugs have been prescribed in an uncontrolled manner in the country, generating a gigantic population of people addicted to medicines such as codeine, which, in turn, took more than 50 years. thousand American citizens to death in 2016.

In the case of opioids, the problem is even greater because these drugs are all made using poppy, the same plant used to make morphine, opium and heroin.

This makes patients addicted to pills jump to cheaper and more affordable drugs, such as heroin, creating a real crisis of substance abuse and drug trafficking in the country.

In Brazil, the situation is not as complicated as that of the USA, but it can become. An article published in the American Journal of Public Health entitled “Trends in the sale of opioids under prescription in Contemporary Brazil” shows that there was a 495% increase in the sale of opioid drugs in the country between 2009 and 2015.

It is necessary to be careful and observe the trends of other countries so that the problems that affect those regions do not become part of the daily life of Brazil, too.

Allergic reactions

Unfortunately, some patients may be allergic to any of the compounds used in the most common drug formulas. For this reason, it is very important to talk to a doctor before taking any medication.

Diagnostic difficulty

If a person takes muscle relaxants with a certain frequency, whenever he feels the slightest pain, he may actually be masking a bigger problem.

She stops going to the doctor when necessary and takes the medication on her own, thus avoiding the visit to the office.

Especially the centrally acting muscle relaxants, those that act directly on the nervous system, can alter patients’ perception of pain, which hinders a person’s perception of themselves, in addition to leaving the doctor with less information.

It could be, for example, that if the patient was not under the effect of muscle relaxants, he could better describe the symptoms, giving the clues that the doctor needs to know the urgency and the seriousness of the situation.



Muscle relaxants are contraindicated for people:

  • Allergic to any of the components of the formulas;
  • Suffering from heart, liver or kidney failure;
  • Who have severe arterial hypertension;
  • Who are hypersensitive to anti-inflammatory drugs;
  • Pregnant women;
  • Lactating women (women who are breastfeeding);
  • Who will do or have just had some cardiac surgery;
  • Who have stomach ulcers.

Drug interaction

Mixing muscle relaxants with substances such as alcohol, for example, can be quite dangerous, as the sedative effect of this medication is intensified, making the combination potentially fatal.

In addition, the combination of muscle relaxants with antihistamines (antiallergics) should be avoided. A 2015 study, published in the journal BMC Geriatrics , demonstrated that the combination of these drugs causes an increase in hospitalization and mortality in the elderly.

Price and where to find

It is difficult to offer an accurate price estimate for muscle relaxants, as they vary widely depending on the composition and dose available in each package.

You will find these drugs in pharmacies and most of them do not require a prescription.

Taking all these factors into account (active ingredient + dose), we can say that the price variation is high, causing it to vary from R $ 2.50 to up to R $ 45.00.

To circumvent this huge price variation, you can use comparator sites, such as Consulta Remédios and choose the option that best suits your needs.

In the case of drugs based on cannabidiol and tetrahydrocannabinol, the purchase of the drug can be a little more complicated, as they are extracted from marijuana, a plant that remains illegal in Brazil, despite its medicinal potential.

For that reason, only people authorized by the courts can buy this medicine.

Natural muscle relaxant

There are several natural alternatives to obtain the muscle relaxing effect. It is important to remember that you should not make use of these alternatives without first consulting a health professional . Check out some:

Peppermint oil

Peppermint oil can be used both as a pain reliever and as a natural muscle relaxant. It has anti-inflammatory and anti-spasmodic properties that work to relieve pain and inflammation while calming spasms and cramps.

How to use?

To use peppermint oil, it is necessary to apply it directly to the affected region and wait for it to take effect.


Epsom salt, known chemically by the name magnesium sulfate, is supplied by a saline source located in Epsom, England. Technically, it is not a salt, but a natural compound of magnesium and sulfate that can be used as a natural remedy.

It is possible to obtain muscle relaxing effects through baths with Epsom salts. This is because this type of salt has high levels of magnesium, which provides the relaxing effect of the muscles.

In addition, magnesium also helps prevent pain and facilitates the treatment of inflammatory conditions such as fibromyalgia and arthritis.

How to use?

Add ½ (half) cup (100g) of Epsom salts to the water in a bowl and soak the inflamed area for 20 minutes. Always try to do this therapy before bed to ensure that your muscles rest.

Peppermint oil

Peppermint oil has anti-inflammatory and analgesic properties that work by reducing pain and facilitating circulation, providing quick relief to the affected region.

How to use?

First moisten your palms with a small amount of peppermint oil and rub over the muscles you want to relax. Massage the area for at least 5 minutes to obtain good results.


Valerian has calming and anti-inflammatory effects, making it possible to use both the oil and the infusion of this plant to reduce muscle stress .

The consumption and direct application of this product helps to reduce inflammation levels, increasing circulation and favoring the oxygenation process.

How to use?

Consume up to 2 cups (500mL) of valerian infusion per day or rub a little valerian oil over the painful area and rest.

Chamomile oil

Chamomile is known for its digestive and emollient properties, but it is also a natural solution that helps to reduce muscle swelling and pain.

As it has antispasmodic and anti-inflammatory properties, it can facilitate the relaxation of muscles, especially when they are tensioned due to stress.

How to use?

Apply chamomile oil to your hands and massage the painful areas.

Arnica oil

Arnica is a plant that contains a chemical compound known as thymol.

Thymol has an anti-inflammatory action, which makes this substance an ally in relieving muscle pain. Direct application of the oil creates a pleasant feeling of warmth and reduces muscle tension.

How to use?

Place several drops of arnica oil on the rigid muscles and massage for 5 minutes. If necessary, repeat 2 times a day.

Cayenne pepper

Cayenne pepper can help fight muscle pain due to an active substance called capsaicin, which gives anti-inflammatory and analgesic effects to this vegetable.

How to use?

Get cayenne pepper oil and massage tired muscles. You can also add small amounts of the pepper in the vitamins and infusions that you eventually use.


The Rosemary is a spice used in cooking as a seasoning in many dishes, but can also contribute their muscle relaxant effect.

How to use?

You can do an immersion bath, diluting a little rosemary to relieve menstrual cramps or muscle spasms. It is also possible to use rosemary essential oil to massage the joints.

Hot compresses on painful and inflamed areas are also an option, especially for those patients who suffer from the symptoms of arthritis.


Passionflower is a plant known to help control nerves, but the truth is that it can also act as an anti-inflammatory and muscle relaxant.

Because it contains phytosterols and flavonoids, two substances with an antioxidant effect that help reduce oxidative stress, this plant can be an ally when it comes to curing muscle pain.

In addition, the nutrients present in its composition can help to regulate the activity of the nervous system and to control problems such as anxiety and insomnia.

How to use?

You can prepare an infusion of passionflower and consume it before bed or, optionally, soak an absorbent cloth in the hot infusion and apply it as a compress to the painful areas.

Cannabis oil

Recent studies have shown that cannabinoids can be useful in fighting pain, inhibiting neuronal transmission related to this sensation.

Cannabis oil has the ability to relieve chronic pain and inflammation, which is why it is sometimes used as a natural treatment for fibromyalgia.

How to use?

In Brazil, the use (with rare exceptions) and the planting of cannabis is still prohibited, so the product is forbidden to Brazilians.

On the other hand, if you live in other Portuguese-speaking countries and have more flexible cannabis policies, such as Portugal, make sure that the oil you bought comes from a reputable company and sells pure oils and tested in the laboratory.

Muscle Relaxing Tea

In addition to the natural alternatives mentioned above, which have more topical use, it is possible to use teas to obtain the muscle relaxing effect. Here are a few:

Valerian tea

As we saw earlier, valerian is a plant that has several properties that can provide a relaxing effect on muscles.

One of the ways to enjoy the benefits of this plant is through the infusion, which has been used for centuries by communities that sought it for the relief or reduction of tension in the neck.

In addition, valerian has a sedative action, can help fight anxiety problems and sleep disorders, being highly recommended for those who need to relax in a natural way.

Chamomile Tea

It is not just chamomile oil that can help with muscle pain. Tea can also provide the effects of muscle relaxation, relieving muscle cramps, tension and pain.

Passion flower tea

The passion flower has a relaxing and analgesic action, helping to improve the symptoms of patients suffering from muscle tension. In addition, passion fruit tea can help fight insomnia, stress and anxiety.

Laurel Tea

Laurel, also known as laurel, is a plant that has an important relaxing action.

The consumption of laurel tea , therefore, is indicated for those who suffer from recurrent muscle pain, and it is possible to use this product to prevent problems and prevent new episodes of muscle tension and cramps.

In addition, the consumption of laurel can help those who suffer from poor digestion, inflammation, anxiety and headaches.

Common questions

Muscle relaxant gives you sleep?

Yes. The muscle relaxant, due to its effect, can cause drowsiness. For this reason, it is recommended that you only take these drugs at night and that the patient does not drive after taking the medicine.

Muscle relaxant hinders the effect of weight training?

Yes, the continuous use of muscle relaxants can disrupt the effects of weight training , more specifically in the process of muscle recovery and adaptation to exercise.

The pain is the result of an inflammatory process caused by the micro injuries in the muscle generated by the wear and tear of the training. It is these small traumas that lead to muscle regeneration and growth.

As muscle relaxants inhibit contraction, and with this, microlesions, the habit of taking these medications makes the results of a workout not so effective.

Feeling pain after a new or heavy workout is common and the best thing to do is to give your body time to overcome it naturally.

After all, that’s how bodybuilding king Arnold Schwarzenegger would say: “No pain, no gain”.