Comparing Armodafinil and Modafinil

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A pharmacist discusses the similarities and differences between these medications used for narcolepsy.

Medically reviewed by Alex Yampolsky, PharmD

Nuvigil (armodafinil) and Provigil (modafinil) are prescription medications. They belong to a drug class known as stimulants.

Healthcare providers prescribe these drugs to help keep individuals awake if they:

Keep reading to learn about both armodafinil and modafinil, when each medication may be prescribed, and the critical differences between the two medication options.

<p>PIKSEL / Getty Images</p> Older female checking prescription with cellphone

PIKSEL / Getty Images

Older female checking prescription with cellphone

What Is Modafinil?

Provigil (modafinil) is a stimulant drug, which means it activates the nervous system. Provigil was approved by U.S. the Food and Drug Administration (FDA) in 1998. The drug is approved to help promote wakefulness in adults with the following sleep disorders:

  • Narcolepsy, or excessive sleepiness throughout the day

  • Sleep apnea, a condition that frequently interrupts breathing during sleep

  • Shift-work sleep disorder, a sleep disorder that can affect individuals who work overnight shifts or rotating shifts, which impacts their sleep/wake schedule

The FDA has not approved modafinil for use in children. So, whether this medication would be safe or effective for people younger than 18 is unknown.

Modafinil comes as an oral tablet with two strengths: 100 milligrams (mg) and 200 mg. The recommended dose and frequency depend on the reason for use as follows:

  • Typical dosage for narcolepsy and sleep apnea: 200 mg once daily in the morning

  • Typical dosage for shift-work sleep disorder: 200 mg taken one hour prior to the start of the work shift

Healthcare professionals may prescribe a lower dose of 100 mg for older adults or individuals with liver problems.

Some healthcare professionals choose to prescribe modafinil for other conditions that the FDA does not explicitly approve, which is called off-label prescribing. In fact, one study from 2013 found that nearly 90% of individuals taking modafinil were prescribed the drug off-label. Examples of off-label uses for modafinil include the following:

What Is Armodafinil?

Nuvigil (armodafinil) is very similar to modafinil. The FDA approved Nuvigil in 2007 to prevent excessive sleepiness in adults with the following sleep-related disorders:

  • Narcolepsy

  • Sleep apnea

  • Shift-work disorder

Armodafinil is not approved for use in children. The drug comes as an oral tablet with four different strengths available: 50 mg, 150 mg, 200 mg, and 250 mg. The recommended dosage varies with the condition treated:

  • Typical dosage for narcolepsy and sleep apnea: 150 mg to 250 mg once daily in the morning.

  • Typical dosage for shift-work sleep disorder: 150 mg taken one hour prior to the start of the work shift

As with modafinil, lower doses (50 mg to 150 mg) are typically recommended for people with liver problems or older adults.

Armodafinil is utilized for many of the same off-label purposes as modafinil. Healthcare providers may prescribe armodafinil off-label for combating fatigue and sleepiness associated with the following:

How Are Armodafinil and Modafinil Different?

Armodafinil and modafinil are very similar medications.

Armodafinil was developed by making a slight change to the formulation of modafinil.

As a result, the main differences are related to their recommended dosages, relative potency (the strength required for a drug to produce an effect), and how long their effect lasts.

On a milligram-per-milligram basis, the stimulant effect of modafinil wears off more quickly than armodafinil.

Even though armodafinil and modafinil have similar half-lives of around 15 hours, the levels of armodafinil in the blood remain higher for a more extended period when both drugs are administered in the same amount.

This is a critical consideration for treating shift-work sleep disorder. If taken an hour before a night shift, the wakefulness-promoting effect of modafinil may wear off during the last third of the shift.

This means the drug's effectiveness in keeping individuals awake diminishes as the night shift progresses toward the early morning hours. This increases the risk of accidents if the individual becomes excessively sleepy while commuting home.

In one study comparing the two medications for shift-work sleep disorder, researchers found that taking 150 mg of armodafinil provides the same safe and effective reduction in sleepiness that 200 mg of modafinil does.

Is Armodafinil or Modafinil Safer?

For most individuals, armodafinil and modafinil are safe medication options for reducing excessive sleepiness due to narcolepsy, sleep apnea, or shift-work sleep disorder.

Given their similarity, both medications are associated with the same side effects discussed below.

One review of multiple studies found no significant safety or side effect differences between the two drugs.

Side Effects

Armodafinil and modafinil can cause similar side effects. Mild side effects commonly include the following:

These side effects may be more likely to occur at higher doses but may ease up or go away after your body adjusts to the medication.

Less commonly, armodafinil or modafinil may result in severe side effects, such as:

If side effects from either drug don’t go away, contact a healthcare provider for advice.

If your symptoms seem severe, call 911 or go to a hospital emergency department right away.


Armodafinil and modafinil have the same contraindications and precautions, as summarized in the table below.

Who should avoid armodafinil or modafinil?

Who should use armodafinil or modafinil cautiously?

Individuals with a history of allergic reactions to armodafinil or modafinil

Individuals with a history of psychosis, depression, or mania
Individuals with continued excessive sleepiness despite armodafinil or modafinil use
Individuals with a history of heart problems Lower doses recommended for individuals with liver problems and seniors (ages 65+)


Drug interactions can alter how a drug works, potentially increasing its side effects or making it less effective.

Armodafinil and modafinil work the same way, and their potential drug interactions are also the same.

The lists below are not complete but highlight some interactions to be aware of while taking armodafinil or modafinil.

Either drug may interact with the following medications, including:

Certain contraceptive (birth control) drugs, such as ethinyl estradiol. Armodafinil and modafinil both can make this type of birth control less effective.

To help prevent pregnancy, ask your provider about switching to a different contraceptive. They may recommend using a backup birth control method (such as condoms) during treatment with armodafinil or modafinil and for at least a month after stopping either drug.

Examples of contraceptives that contain ethinyl estradiol include the following:

Some medications that suppress (weaken) the immune system, like Gengraf (cyclosporine). When taken with cyclosporine, armodafinil and modafinil lower the levels of cyclosporine in the body, making this medication less effective.

Certain medications metabolized in the liver, such as Prilosec (omeprazole) and Dilantin (phenytoin). Armodafinil and modafinil increase the level of these drugs in the body, potentially leading to increased side effects.

Before taking armodafinil or modafinil, talk to a healthcare professional about all other medications you take to help avoid harmful interactions.

Nutrition Considerations

There are no foods known to interact with armodafinil or modafinil. Either drug may be taken with or without food.

However, the FDA warns against consuming alcohol while taking either armodafinil or modafinil because the combination may increase the risk of side effects.


Nuvigil (armodafinil) and Provigil (modafinil) are similar stimulant medications for reducing excessive sleepiness from the following:

  • Narcolepsy

  • Sleep apnea

  • Shift-work sleep disorder

These two medications have much in common, including how they work, potential side effects, precautions, and interactions.

The main differences are:

  • Dosages

  • Relative potency (the strength required for a drug to produce an effect)

  • How long their effect lasts compared on a milligram-per-milligram basis

Talk with a healthcare provider to determine if one of these medications may work for you.

Frequently Asked Questions

Can you take modafinil and armodafinil together?

Modafinil and armodafinil should not be taken together. They are very similar medications, so combining them isn’t going to provide much additional benefit. However, taking them together could increase the risk of severe side effects, such as heart problems.

What are the differences between armodafinil and modafinil?

Armodafinil is a newer, slightly altered version of modafinil. Though the medications are similarly safe and effective in helping individuals with sleeping disorders stay awake, armodafinil’s effect may last longer than modafinil’s.

Can someone experience addiction or drug dependence with modafinil or armodafinil?

Armodafinil and modafinil share some similarities with other stimulants such as Concerta (methylphenidate) and Adderall (amphetamine/dextroamphetamine). This suggests there is a possibility of drug dependence with armodafinil and modafinil, just like with the other stimulants. Both drugs are classified as Schedule IV (four) controlled substances. However, studies have not shown any withdrawal symptoms when stopping either of these drugs.

Read the original article on Verywell Health.