Tonmya is a prescription medicine for fibromyalgia in adults. It is a low dose of cyclobenzaprine in a tablet that dissolves under your tongue at bedtime. The FDA approved it on August 15, 2025, making it the first new fibromyalgia medicine in more than 15 years.
If you are curious about Tonmya and fibromyalgia, this article covers what it is, how it is taken, who should not use it and what side effects to expect. Use it to get ready for a conversation with your own provider.
What Is Tonmya?
Tonmya is the brand name for cyclobenzaprine hydrochloride sublingual tablets. “Sublingual” means under the tongue. Each tablet is 2.8 mg.
You may already know cyclobenzaprine. It has been used for years as a muscle relaxant in a pill you swallow. Tonmya is different in a few ways:
- It is made to dissolve under the tongue, so the medicine is absorbed through the lining of your mouth.
- It is a lower dose than the usual muscle relaxant tablets.
- It is approved specifically to treat fibromyalgia, not short-term muscle spasms.
Tonmya is not an opioid. It is meant to be taken once a day at bedtime.
How Tonmya Is Taken
Your prescriber will give you exact directions. Based on the FDA label, here is the general plan.
The dose
- First two weeks: one tablet (2.8 mg) under the tongue at bedtime.
- From day 15 on: two tablets (5.6 mg) at bedtime, if your prescriber increases it.
- The maximum is 5.6 mg a day.
- Adults 65 and older, and people with mild liver problems, are usually kept at one tablet. It is not recommended for people with moderate or severe liver problems.
Step by step at bedtime
- Brush your teeth and finish your mouth care first.
- Take a few sips of water to moisten your mouth, especially under the tongue.
- Place the tablet (or tablets) under your tongue and let it dissolve. Do not swallow, chew, crush or cut it.
- Do not eat or drink for at least 15 minutes after it dissolves.
- Try not to talk for at least 5 minutes.
- If you can, skip hot, cold or acidic drinks until morning.
If you miss a dose, the label says to skip it and take your next dose the following night. Do not take it during the day, and do not take two doses to make up for one.
How Tonmya May Help Fibromyalgia
In clinical trials, people taking Tonmya had a greater drop in daily pain scores after 14 weeks than people taking a placebo. More people on Tonmya also had a meaningful (30 percent or more) improvement in pain.
Sleep is a big part of the story. Poor, unrefreshing sleep is one of the core problems in fibromyalgia, and Tonmya is taken at bedtime. In one large phase 3 trial, people on Tonmya reported better sleep quality and less fatigue than those on placebo. They also reported improvements in overall symptoms and daily function.
It is important to keep expectations realistic. Tonmya is not a cure, and not everyone will respond. It is usually one part of a wider plan that includes movement, sleep habits and other support.
Who Should Not Take Tonmya
The FDA label lists people who should not take Tonmya. Do not use it if you:
- Are allergic to cyclobenzaprine or any ingredient in the tablet.
- Take an MAO inhibitor (a type of antidepressant), or have stopped one within the last 14 days.
- Are in the recovery phase after a recent heart attack.
- Have heart rhythm problems, heart block or other problems with the heart’s electrical system.
- Have heart failure.
- Have an overactive thyroid (hyperthyroidism).
Pregnancy warning
Animal studies suggest Tonmya may harm an unborn baby, especially early in pregnancy. Because of this, the label says:
- People who could become pregnant should have a pregnancy test before starting.
- Use effective birth control while taking Tonmya and for two weeks after the last dose.
- Avoid Tonmya from two weeks before trying to conceive through the first trimester.
If you are pregnant, planning a pregnancy or breastfeeding, talk with your prescriber before starting.
Other Important Warnings
The label also describes some serious but less common risks.
- Serotonin syndrome. This can happen when Tonmya is combined with other medicines that raise serotonin. Examples include many antidepressants (SSRIs, SNRIs and tricyclics), tramadol and bupropion. Signs include agitation, fast heartbeat, fever, sweating, shaking, muscle twitching and diarrhea. Get emergency help if these happen.
- Heart and seizure effects. Because Tonmya is related to older tricyclic medicines, it may affect heart rhythm and may lower the seizure threshold.
- Drowsiness. It can affect your ability to drive or use machines. Alcohol and other sedating medicines can make this worse.
- Anticholinergic effects. Use caution if you have trouble emptying your bladder, a certain type of glaucoma (angle-closure) or take other medicines with similar effects.
Many people with fibromyalgia already take an antidepressant. Make sure your prescriber and pharmacist know every medicine and supplement you take.
Side Effects
The most common side effects in studies were in the mouth. The label reports that mouth reactions happened in 43 percent of people taking Tonmya, compared with 8 percent on placebo. Most began within minutes and went away within an hour.
Common side effects include:
- Numbness in the mouth (the most common, in about 23 percent)
- Mouth discomfort or pain
- A strange taste
- Tingling in the mouth
- Sleepiness
- Fatigue
- Dry mouth
- Mouth sores
Moistening your mouth with water before each dose can lower the chance of mouth reactions. If they are severe or do not settle, let your prescriber know.
Questions to Ask Your Doctor
Bring these questions to your appointment:
- Is Tonmya a good fit for my symptoms, especially my sleep?
- Do any of my current medicines interact with it? Do I take anything that raises serotonin?
- Does my heart history or thyroid make it unsafe for me?
- Do I need a pregnancy test or a birth control plan first?
- How long should I try it before we decide if it is working?
- What should I do if the mouth numbness bothers me?
- How does it fit with my other fibromyalgia treatments?
Never stop or change your current medicines on your own to make room for a new one. Your prescriber can help plan any changes safely.
Cost and Insurance
Tonmya is a new brand-name medicine, and new brand-name medicines often cost more than older generics. What you pay will depend on your insurance plan.
Some plans may need extra steps before they cover it, such as prior authorization or trying other medicines first. Ask your prescriber’s office and your pharmacy to check your coverage. You can also ask whether the manufacturer offers a savings program, and whether you qualify.
Frequently Asked Questions
Is Tonmya the same as regular cyclobenzaprine?
They contain the same active medicine, but they are not the same product. Tonmya is a lower-dose tablet made to dissolve under the tongue and is approved for fibromyalgia. Do not swap one for the other without your prescriber’s direction.
When did Tonmya become available?
The FDA approved Tonmya on August 15, 2025. It became available in U.S. pharmacies in late 2025.
Is Tonmya an opioid?
No. Tonmya is not an opioid. It is taken once a day at bedtime.
Why does Tonmya make my mouth numb?
Mouth numbness and tingling are the most common side effects, because the tablet dissolves against the lining of your mouth. For most people it fades within an hour. Wetting your mouth before each dose may help.
The Bottom Line
Tonmya is a bedtime tablet that dissolves under the tongue and is approved to treat fibromyalgia in adults. In studies, it eased pain and improved sleep quality for many people, but it is not right for everyone. People with certain heart problems, an overactive thyroid or recent MAO inhibitor use should not take it, and there are important pregnancy warnings. Talk with your prescriber about whether it fits into your treatment plan.
Sources
- TONMYA Prescribing Information (FDA)
- FDA approves Tonmya for fibromyalgia treatment (Healio)
- TNX-102 SL Significantly Reduces Daily Pain, Improves Fibromyalgia Symptoms (HCPLive)
- Fibromyalgia – Diagnosis and treatment (Mayo Clinic)
- Fibromyalgia (American College of Rheumatology)
New from Anna Curran, RN
Fibromyalgia: A Nurse’s Guide to Less Pain, Better Sleep and More Good Days
A plain-language guide to medicines, pacing, sleep, gentle movement, flares, work and family life, with trackers and planners. Paperback, hardcover and Kindle.
This article is for general education only and is not medical advice. Talk with your own doctor or licensed provider before you start, stop or change any treatment. In an emergency, call 911. In crisis, call or text 988. See our medical disclaimer.