Many new mothers deal with back pain, neck tension, or headaches while caring for a newborn. If you are breastfeeding, reaching for a muscle relaxer might seem like a quick fix. The short answer is that some muscle relaxers are considered compatible with breastfeeding, but most are not well-studied, and none are completely risk-free. You should never take one without speaking to your doctor first, because the specific medication, your dose, and your baby’s age all matter.
What Are Muscle Relaxers and How Do They Work?
Muscle relaxers are prescription medications used to treat muscle spasms, spasticity, and certain types of pain. They work on the central nervous system to reduce the signals that cause muscles to tighten. Common examples include cyclobenzaprine (Flexeril), methocarbamol (Robaxin), baclofen, tizanidine, and carisoprodol (Soma).
These drugs are not all the same. They belong to different chemical classes and behave differently in the body. That difference matters a great deal when you are breastfeeding, because each drug transfers into breast milk at a different rate.
Can I Take A Muscle Relaxer While Breastfeeding?
The safest muscle relaxer options while breastfeeding are cyclobenzaprine and methocarbamol, based on limited data. Most other muscle relaxers either lack sufficient research or have known risks that make them less desirable choices. However, even for the “safer” options, the evidence base is thin. No large human trials have confirmed their safety in nursing mothers.
Cyclobenzaprine passes into breast milk in very low amounts. Most sources consider it compatible with breastfeeding when used at standard doses for a short time. Methocarbamol also appears to transfer minimally, though the data comes from older case reports rather than modern controlled studies.
Baclofen has some data showing low levels in breast milk, but reports of infant side effects exist. Tizanidine has almost no published data on breastfeeding. Carisoprodol is generally avoided because its active breakdown product passes more readily into breast milk and can cause sedation in infants.
Why the Evidence Is Limited
Researchers cannot ethically run large clinical trials on pregnant or nursing women. That means most safety information comes from case reports, small observational studies, and expert opinion. This is not the same as solid evidence, but it is often the best data available.
What this means for you: your doctor will likely make a recommendation based on the drug’s known properties, your specific situation, and your baby’s health. If a medication has been used widely for decades without reports of serious harm, that experience carries some weight even without formal trials.
Still, “widely used” is not the same as “proven safe.” You should always weigh the benefit of treating your pain against the unknown risk to your baby.
How Muscle Relaxers Transfer Into Breast Milk
When you take any medication, a portion enters your bloodstream. From there, some of it moves into your breast milk. The amount depends on several factors including the drug’s molecular size, how well it dissolves in fat, and how long it stays in your body.
Drugs with short half-lives leave your system faster. Drugs with longer half-lives build up in your blood and milk over time. Cyclobenzaprine has a relatively long half-life, which means it stays in your system longer than some other options. Even so, the measured levels in breast milk remain low.
Your baby’s age also matters. A newborn’s liver and kidneys are immature. They cannot clear medications as quickly as an older infant. A one-week-old baby is at higher risk of drug accumulation than a nine-month-old. If you take a muscle relaxer, your doctor may suggest timing your dose right after a feeding to reduce the amount your baby receives.
Risks to Watch For in Your Baby
If your baby receives any medication through breast milk, the most common concerns are drowsiness, poor feeding, and low muscle tone. These effects are more likely with muscle relaxers because the drugs work by calming the nervous system.
Watch for these signs in your baby:
- Sleeping more than usual or hard to wake
- Feeding less than normal
- Floppy or limp limbs
- Weak cry
- Breathing changes
If you notice any of these, stop the medication and contact your pediatrician immediately. Breathing problems are a medical emergency. Call 911 if your baby is struggling to breathe or has blue lips or skin.
What About Over-the-Counter Options?
No muscle relaxers are available over the counter in the United States. The products you see on pharmacy shelves for muscle pain are not true muscle relaxers. They are either pain relievers like acetaminophen or ibuprofen, or topical creams that numb the skin.
Acetaminophen and ibuprofen are generally considered safe while breastfeeding. They are often the first-line options for pain. Many doctors recommend trying these before considering a prescription muscle relaxer.
Some people try magnesium supplements or herbal remedies for muscle tension. The evidence for these is weak. No clinical evidence currently confirms that any supplement works as well as a prescription muscle relaxer, and supplements are not regulated for safety or purity. If you are considering one, talk to your doctor first.
Non-Medication Approaches for Muscle Pain
Before you take any medication, consider whether non-drug approaches might help. Heat therapy, gentle stretching, massage, and physical therapy can all relieve muscle tension without exposing your baby to anything.
Posture changes matter too. New mothers often strain their backs and necks from holding a baby, bending over a crib, or sitting in awkward nursing positions. A lactation consultant can help you find more comfortable breastfeeding positions. A physical therapist can teach you safe lifting and carrying techniques.
These approaches do not work as fast as a pill, but they address the root cause of the problem. Muscle relaxers treat the symptom, not the underlying strain.
Questions to Ask Your Doctor
If your pain is severe enough that you are considering a muscle relaxer, have a direct conversation with your doctor. Come prepared with questions.
Ask which specific muscle relaxer they recommend and why. Ask how long you should take it. Ask whether a short course of a few days is safer than long-term use. Ask if you can time your doses to minimize the amount in your milk.
Be honest about your baby’s age, your baby’s health, and any other medications you take. If your baby was born prematurely, that changes the risk calculation significantly. Premature infants clear drugs even more slowly than full-term newborns.
Frequently Asked Questions
Can I take Flexeril while breastfeeding?
Cyclobenzaprine (Flexeril) is generally considered one of the safer muscle relaxer options during breastfeeding because very low levels pass into breast milk. You should still talk to your doctor before taking it, especially if your baby is a newborn.
How long does a muscle relaxer stay in breast milk?
Most muscle relaxers reach their peak level in breast milk a few hours after you take the dose. The exact time depends on the specific drug, but taking your dose right after a feeding can help reduce your baby’s exposure.
Is it safe to take Tylenol or ibuprofen with a muscle relaxer?
Acetaminophen and ibuprofen are considered safe while breastfeeding and are often used alongside muscle relaxers for pain. Tell your doctor everything you are taking so they can check for interactions.
What muscle relaxers should I avoid while breastfeeding?
Carisoprodol (Soma) is generally avoided because its active breakdown product passes into breast milk more readily and can cause sedation in infants. Tizanidine has almost no published safety data, so most doctors avoid it when alternatives exist.
Muscle pain is miserable, especially when you are also caring for a newborn. The honest answer is that no muscle relaxer is proven 100 percent safe during breastfeeding, but some are used widely without reported problems. Your best move is to talk to your doctor about your specific situation, try non-drug approaches first, and only use medication if the benefit clearly outweighs the risk.
