A normal dose of cyclobenzaprine is 5 mg to 10 mg taken three times a day for the immediate-release tablet, or 15 mg once daily for the extended-release capsule. The maximum recommended amount is 30 mg per day for either form. Cyclobenzaprine is a muscle relaxant prescribed for short-term relief of muscle spasms, typically alongside rest and physical therapy.
Immediate-Release Tablets
The immediate-release version of cyclobenzaprine comes in 5 mg, 7.5 mg, and 10 mg tablets. Most adults start at 5 mg three times a day, with the option to increase to 7.5 mg or 10 mg three times daily depending on how well it works and how well it’s tolerated. The ceiling is 30 mg total per day, split across those three doses.
Many prescribers start at the lower 5 mg dose because it often provides meaningful relief with fewer side effects, particularly drowsiness. If 5 mg isn’t enough, the dose can be gradually increased.
Extended-Release Capsules
The extended-release form is designed for once-daily dosing. The standard starting dose is one 15 mg capsule per day. If that’s not sufficient, the dose can be increased to 30 mg once daily, either as a single 30 mg capsule or two 15 mg capsules taken together.
Take the capsule at roughly the same time each day. Food matters here: taking the extended-release capsule with a meal increases absorption by about 20% and raises peak blood levels by around 35% compared to taking it on an empty stomach. If you have trouble swallowing capsules, the contents can be sprinkled over applesauce and swallowed without chewing. Other foods haven’t been tested for this purpose.
Lower Doses for Older Adults and Liver Problems
Older adults and people with liver impairment need lower doses. Both groups should start at 5 mg and increase slowly, with less frequent dosing than the standard three-times-daily schedule. The drug is broken down by the liver, so reduced liver function means it stays in your system longer and its effects, including side effects, are amplified.
For people with moderate to severe liver impairment, cyclobenzaprine is generally not recommended at all due to a lack of safety data in that group.
How Long You Should Take It
Cyclobenzaprine is meant for short-term use, generally no more than two to three weeks. Muscle spasms from acute injuries typically improve within that window, and the drug hasn’t been shown to offer additional benefit beyond that period. It’s not intended for chronic muscle conditions or long-term pain management.
How It Works
Cyclobenzaprine reduces muscle spasms by acting in the brain rather than directly on the muscles themselves. It dampens the nerve signals that cause muscles to tighten and spasm. This is why drowsiness is such a common side effect: the drug’s activity in the brain produces sedation alongside the muscle-relaxing effect. Most people notice the sedation is strongest in the first few days and gradually becomes more manageable.
Serotonin Syndrome Risk
One serious concern with cyclobenzaprine is its potential to cause serotonin syndrome, a dangerous condition where too much serotonin builds up in the brain. Symptoms include agitation, rapid heartbeat, high body temperature, muscle twitching, and in severe cases, seizures.
This risk increases significantly when cyclobenzaprine is combined with other drugs that also raise serotonin levels. The FDA specifically flags common antidepressants (SSRIs and SNRIs), older tricyclic antidepressants, the pain medications tramadol and meperidine, bupropion, verapamil, and MAO inhibitors. If you take any of these medications, that’s important information to share before starting cyclobenzaprine.
Common Side Effects at Normal Doses
Even at standard doses, cyclobenzaprine reliably causes drowsiness. Dry mouth and dizziness are also very common. These effects tend to be more pronounced at 10 mg three times daily compared to 5 mg three times daily, which is one reason many people do well at the lower dose. The drowsiness can be useful if muscle spasms are disrupting your sleep, but it can impair your ability to drive or operate machinery during the day.