Armodafinil Vs. Modafinil: Differences, Interactions, and Side Effects

Armodafinil vs. Modafinil

Armodafinil and Modafinil are both wakefulness-promoting agents with many similarities but show differences in their brand names, efficacy, half-life, and chemical structure.

People who suffer from narcolepsy or excessive sleepiness often need medications to keep themselves from falling asleep at odd hours. These medications are called wakefulness-promoting agents that promote the concentration of certain natural substances in the brain responsible for wakefulness.

Two such drugs are Armodafinil and Modafinil. They are used to treat disorders such as narcolepsy, shift work disorder, obstructive sleep apnea/hypopnea syndrome, etc. While both of these drugs are closely related and used for the same purposes, they have some differences. This article will discuss the differences between Armodafinil and Modafinil and their interactions and side effects.

Differences Between Armodafinil and Modafinil

Armodafinil and Modafinil share a vast number of similarities. However, some factors set them apart. Let’s discuss some of these factors.

Brand Name

The brand names of both of these drugs are different. Armodafinil goes by the brand name Nuvigil and Modafinil has the brand name Provigil.

Standard Dosage

The standard dosage of Armodafinil is 150 mg once per day, and that of Modafinil is 200 mg once per day. Both of them are taken as oral tablets.

Chemical Structure

The significant difference between Armodafinil and Modafinil is their chemical structures. Armodafinil is a relatively newer drug and is derived from Modafinil. It is basically the R-enantiomer of Modafinil.


The half-life of a drug suggests how long that drug stays in your system or how long it takes for your body to eliminate it. In this regard, Armodafinil has a longer half-life as compared to Modafinil. Due to this reason, Armodafinil has often been considered the stronger drug among these two and is known to have better wakefulness effects.


When compared according to their potency, Armodafinil has longer-lasting effects than Modafinil. Both of these drugs are used for treating conditions such as narcolepsy, shift work disorder, obstructive apnea, etc. They are used off-label in multiple sclerosis, cancer-related fatigue, and psychiatric disorders such as ADHD and depression.

According to a study, Armodafinil is shown to have higher plasma concentrations later in the day. It is due to these higher concentrations that Armodafinil works better than Modafinil.


When prescribing medications, it is crucial to consider their cost and what the patient can afford. Armodafinil is relatively cheaper than Modafinil. The retail price of generic Armodafinil is $500. However, it can also be bought at a price as low as $277 in the form of Armodafinil.

On the other hand, Modafinil costs over $600.

Side Effects of Armodafinil and Modafinil

Like every medication, Armodafinil and Modafinil have a variety of side effects. These side effects can range from mild to severe.

Here are some of the most common side effects of these medications:

  • Headache
  • Nausea
  • Dizziness
  • insomnia

Modafinil can also cause additional symptoms such as:

  • Nervousness
  • Nasal congestion (rhinitis)
  • Diarrhea
  • Back pain

Other common side effects of both these medications include:

  • Dry mouth
  • Indigestion (dyspepsia)
  • Anxiety
  • Weight loss
  • Decreased appetite

Serious side effects of Armodafinil and Modafinil include:

  • Allergic reactions such as rash and shortness of breathe
  • Psychiatric side effects such as depression and psychosis

If you experience common side effects for extended periods or severe side effects, inform your doctor immediately and seek medical advice.

Read Other Blog Articles

Drug Interactions

Armodafinil and Modafinil share the same drug interactions, apart from their many differences. These drugs can impact how certain drugs are processed in the body mainly because they are the inducers of the CYP3A4 enzyme and inhibitors of the CYP2C19 enzyme.

Among the most popular interactions are contraceptives. Armodafinil and Modafinil can result in decreased effectiveness of steroidal contraceptives such as Ethinyl estradiol or norethindrone. They can lead to accidental pregnancies in women who are taking these medications and want contraception at the same time. So if you are taking either Armodafinil or Modafinil and want to prevent conception, opt for an alternate method of contraception. This caution should be performed both during the treatment with these medications and up till one month after discontinuing the drugs.

Moreover, Armodafinil and Modafinil may increase the clearance of cyclosporine, which is an immunosuppressant from the body. If you use any of these medications simultaneously with cyclosporine, it can reduce the effectiveness of cyclosporine.

Another interaction includes CYP2C19 substrates such as omeprazole, diazepam, phenytoin, etc. Armodafinil and Modafinil reduce the clearance of CYP2C19 substrates from the body, resulting in increased concentrations of these drugs. This may lead to adverse effects and toxicity of CYP2C19 substrates due to their accumulation.


Frequently Asked Questions (FAQs)

Which is more robust – Armodafinil or Modafinil?

Due to its longer-lasting effects and longer half-life, Armodafinil is a more potent drug. It causes increased plasma concentration later in the day, making it more powerful in treating daytime somnolence.

Does Modafinil interact with anything?

Yes, it does. Modafinil shares its drug interactions with Armodafinil. It reduces the effectiveness of steroidal contraceptives such as Ethinyl Estradiol, reduces the concentration of Cyclosporine in the body, and increases the concentration of CYP2C19 substrates such as Omeprazole, Diazepam, and Phenytoin.

Who should not take Armodafinil?

You should not take Armodafinil if you have a history of allergies to its active ingredients. Suppose you are prone to driving or taking part in risky activities while on these medications; you should avoid either of these tasks. People should not take armodafinil with a history of psychiatric illnesses such as psychosis or depression. Those with high blood pressure or heart disease should be monitored when on this medication.

Is Armodafinil bad for your heart?

Yes. Armodafinil is contraindicated in people with heart disease or hypertension. It can cause palpitations or other aggravated symptoms in the mentioned conditions.

Posted by

Qwark writing staff is a team of pharmacists, nurse practitioners, and doctors.

Leave a Reply