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Modafinil Dosage and Administration: A Comprehensive Guide

Last updated on 11 Sep, 2023

Modafinil is available in the dosage strengths of 100 mg and 200 mg, and the standard dosage of this drug is 200 mg which can be taken for various on-label and off-label purposes.

Modafinil is a popular wakefulness-promoting drug that is used for various on-label and off-label purposes. 

As with any medicine, it is crucial to follow the dosage guidelines to ensure safety and effectiveness therefore, in this context, we will explore the topic of Modafinil dosage and administration in detail.

This dosage guide can help you achieve the desired outcome while reducing the risk of side effects.

What is Modafinil?

Modafinil is a eugeroic drug available under various brand names such as Modalert and Modvigil, among others. It is a  Schedule IV controlled substance and is approved by the FDA to treat various sleep disorders such as narcolepsy, obstructive sleep apnea, and shift work sleep disorder. 

Modafinil's Mechanism of Action

The mechanism of action of Modafinil includes its weak dopamine reuptake inhibitor. The effect of the medication results in stimulating the human brain and helping individuals not to fall asleep quickly. It also helps increase your alertness as well as your focus level [1].

Absorption, Metabolism, and Excretion of Modafinil

Modafinil Absorption -

Modafinil is absorbed readily after administration orally. It is insoluble(incapable of dissolving) in an aqueous solution; therefore, it cannot be taken intravenously. 

It reaches maximum plasma concentration in 2-4 hours after administration.

Modafinil Metabolism -

Modafinil is metabolized in the liver through various pathways, such as CYP3A4.

Modafinil Elimination -

The elimination half-life of this popular nootropic in healthy people is approximately 15 hours, and 80% Of the dose is recovered in the form of metabolites in urine [2]. 

Dosing Information of Modafinil

Modafinil tablets are available exclusively in the dosage strength of 100mg and 200mg. The dosage of Modafinil capsules will be different from patient to patient, depending on the severity of the disease.

In most cases, Modafinil starting dose is 200 mg, but with time, your doctor may need to make a dosage adjustment of the nootropic.

Modafinil dosage for narcolepsy

For narcolepsy, people over 17 years of age are recommended a dose of 200mg/day with food or without food. You should consult your health experts before consuming this medicine. However, your health professionals might increase your dose depending on your needs.

Modafinil for Shift Work Disorder

The recommended dose of Modafinil for shift work sleep disorder for people above 17 years of age is 200mg/day. This should be consumed 1 hour prior to starting your work.

Modafinil dosage for sleep apnea

Modafinil should be taken at a dosage of 200 mg to treat sleepiness associated with sleep apnea [3]. 

Modafinil dosage for off-label indications

Modafinil dosage for ADHD-

The Modafinil dosage for ADHD for adults ranges between 100 mg to 200 mg per day, and it is important to keep in mind that the FDA does not approve the use of Modafinil in children. Thus, even a low amount of this drug is not recommended for use in children [4]. 

Modafinil Dosage for Depression -

People who are suffering from depression can take Modafinil at a dose of 200 mg in the morning without exceeding the daily limit of 400 mg.

Modafinil dosage for cognitive enhancement -

Modafinil is known as a smart drug for its numerous benefits and is frequently used by people for cognitive enhancement.

If you want to enhance your cognition, then you can take Modafinil at a dosage of 100-200 mg [5]. 

Modafinil dosage for weight loss -

There is no dosage of Modafinil for weight loss, and the drug is not approved for this purpose. Although this nootropic can cause weight loss, this could be due to loss of appetite, a possible side effect of Modafinil [6]. 

How should Modafinil be taken?

Below are a few tips on how to take the potent nootropic Modafinil -

  • Before taking Modafinil, always read the leaflet from inside the pack because it will give you the necessary information about the nootropic.

  • Modafinil should be taken orally and should be swallowed whole with a glass of water.

  • Do not crush or chew the nootropic.

  • Take the medicine with or without food.

  • Modafinil should be taken at the same time each day and as prescribed by your doctor.

Factors that Affect Modafinil Dosage

Some of the factors that affect the Modafinil Dosage are -


Age is a common factor that may affect Modafinil dosage because, with age, your metabolism slows down, affecting the way your medicines are absorbed.

Liver and kidney function:

Modafinil dosage might also depend on your liver function and renal function. The doctors decrease the dosage if your liver or kidney is not functioning well [7]. 

Modafinil Overdose

Modafinil Overdose is harmful to your health. Some of the common symptoms of Modafinil Overdose are Headache, Dizziness, Anxiety, Trouble sleeping, and a fast heartbeat. If anyone suffers any of the symptoms after ingesting Modafinil, they should immediately consult their health experts. 

There are certain risk factors associated with Overdosing. Some of them are listed below.

  1. Hypertension

  2. Agitation

  3. Hallucination

  4. Delusion [8].

What happens if I miss a dose?

If you miss a dose of Modafinil, there is no need to worry about the missed dose. You can skip the missed dose and return to your regular dosing schedule. 

Modafinil Half-Life and Duration of Action

The half-life of Modafinil for most people ranges between 10-12 hours. It can also last up to 15 hours for some patients. 

The duration of action of Modafinil and its metabolites is present in the Urine for up to 30 hours following ingestion [9]. 

Modafinil Storage

Modafinil should be kept out of the reach of children and should be stored at room temperature, away from heat and moisture. They should be kept in a safe place because they have a high chance of being misused.

Modafinil Precautions And Warning - What You Should Know

  • You should inform your doctor if you are allergic to this medication or any other medicine of the same composition. 

  • You should completely discuss your medical history with your consultant or experts. 

  • Do not combine Modafinil ad Alcohol because it can worsen the side effects.

  • Pregnant and breastfeeding women should not take this nootropic without consulting a doctor.

  • People with kidney, liver, and heart problems should take this medicine with caution.

  • Modafinil has no clearance by the FDA for pediatric use; therefore, this medicine should be kept away from children.

  • The geriatric population should be closely monitored while they’re on this nootropic.

Modafinil Side Effects

Some common Modafinil side effects are listed below [10]. 


Less common 




Rapid heartbeat

Upset stomach


Swelling of lips, tongue, or face 

Loss of appetite


Trouble breathing

Back pain





Severe rash 







Runny nose




Dry mouth


Modafinil Drug Interactions 

Modafinil may decrease the serum concentration of several drugs such as cyclosporine, clozapine, clarithromycin, antiretroviral and antihepaciviral combination products, guanfacine, lurasidone, ranolazine, opioids (e.g., fentanyl, hydrocodone, codeine), zolpidem and estrogen derivatives.

The serum concentration of Modafinil may be reduced in the presence of drugs that induce CYP3A4, including St. John’s Wort, efavirenz, rifampin, and phenytoin and conversely, serum concentration of this nootropic may be increased in the presence of a drug that inhibits CYP3A4 (azole antifungals, ritonavir, and clarithromycin [2].

Modafinil Dosage and Administration - Conclusion 

Modafinil is a very powerful nootropic with multiple benefits. When you’re taking this Central Nervous System stimulant, be sure to monitor your correct dosage and use. 

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Modafinil is generally safe to take daily with the proper consultation of your health experts. If your body can tolerate it well, it is safe.

Modafinil generally takes 30–60 minutes to function after its consumption.

The best time to take Modafinil is in the morning time of day or as advised by your doctor.

Alcohol should be completely avoided while consuming Modafinil.

The reaches its maximum peak concentration in 2-4 hours.


  1. Modafinil Mechanism of Action, How long does Provigil last, addiction resource
  2. Modafinil, NCBI

  3. Modafinil Oral Route, Mayo Clinic.

  4. Modafinil Dosage Guide: 50mg, 100mg, 200mg or 400mg dose.

  5. Modafinil Dosage Guide: Finding your perfect dose

  6. Dosage details for Provigil, Healthline

  7. As you age: You and Your medicines, FDA
  8. Modafinil Overdose, modafiniladhd

  9. How long does Modafinil Stay In your System, the recovery village.

  10. Provigil,(modafinil), medicalnewstoday


Disclaimer: We do not provide any medical advice.

The contents of Healthma are for informational purpose only and is taken by a thorough evaluation of research papers and Journals. We do not provide professional medical advice, treatment, or diagnosis. We advise all readers to consult a physician before consuming any medication mentioned on the website.