So you’re interested in trying some modafinil for yourself but aren’t sure how long the medication lasts.
Compared to other medications, modafinil is very long lasting. It can last between 16 and 22 hours, but varies a lot depending on your genetic factors, and what else was taken along with the modafinil.
Understanding how long modafinil lasts will depend on some important considerations. It’s also necessary to remember that everyone is different.
Here we go over how long the effects of modafinil last, what factors can affect this, and what you can do to make it last shorter or longer.
The Benefits of Modafinil
Modafinil has a long list of benefits, primarily involving its ability to promote wakefulness.
Doctors prescribe the medication for conditions involving “excessive sleepiness”. This includes conditions like narcolepsy and sleep disturbances involved with shift work.
Off-label use of the medication stretch into other areas.
One of the most common uses of modafinil is as a tool for boosting productivity at work or university.
Its ability to delay the onset of fatigue for several hours makes it useful for stretching the amount of time you can work on a project before becoming too tired to keep going.
It’s not uncommon to hear of people spending as many as 20 hours straight on a project before finally calling it quits.
Modafinil offers profound improvement in overall productivity, making it especially popular among people with heavy workloads or time-sensitive projects.
Business executives, university students, entrepreneurs, and creatives are among the majority of people using modafinil to enhance their productivity. It helps them earn more money at work, move up the ranks, and get through tough university degrees.
modafinil is also used to alleviate the symptoms of ADHD by boosting dopamine concentrations in the brain. This works to increase one’s ability to concentrate on a single task for long periods of time.
Where to Buy Modafinil
Modafinil is offered for sale by a number of online vendors.
These vendors operate in a legal grey area in terms of modafinil regulation. This is because the laws around the sale of this prescription-only medication only specifically mention the SALE of modafinil, rather than its purchase.
In most countries, modafinil can be bought online without a prescription.
We primarily use a vendor called AfinilExpress.com. If you use the coupon code MODAFINILORG at checkout you can save an additional 10% on your order.
How Long do the Effects of Modafinil Last?
Measuring how long modafinil lasts means looking at a few different metrics.
We need to know how long it takes for modafinil to start producing effects when it reaches its peak, and how long it takes for enough of the compound to be eliminated from the bloodstream so that it no longer produces any of its effects.
Step 1. Modafinil Absorption
Roughly 40–65% of the modafinil you take is absorbed into the bloodstream .
This can vary depending on the health of your gastrointestinal tract.
It’s very common for people to have chronic inflammatory states in the gastrointestinal tract, which can reduce the amount of modafinil that’s absorbed into the bloodstream.
People suffering from even mild inflammation, but especially from more severe inflammatory states like Celiac disease, IBD, or IBS may have a significantly lower absorption rate through the intestinal tract.
In most people, modafinil is absorbed relatively quickly over the course of 45 minutes. If taken with food, or you have a slow digestive function, this can take as long as 2 hours.
2. The Onset of Effects
Once the drug is absorbed through the digestive tract, 45-60 minutes later, it quickly reaches peak concentrations.
Around the 4–6 hour mark, you will feel the strongest effects of the modafinil. This usually lasts another two hours.
3. The Half-Life of Modafinil
The half-life of modafinil is about 12 to 15 hours.
A lot of websites discuss half-life, but don’t actually tell you what this means or why it’s important.
Drug half-life is a measurement of the time it takes for exactly half the drug to be eliminated from the bloodstream.
This means the compound was either destroyed in the bloodstream or eliminated from the body through the kidneys or digestive tract, or both.
Half-life doesn’t work like you probably think it does.
If the half-life says 10 hours, it doesn’t mean the drug is completely gone in 20 hours. Instead, the dose is cut in half every 10 hours.
For example: If you take 500 mg of a drug and the half-life is 10 hours, it means that there will be 250 mg left at the 10-hour mark—makes sense right?— 10 hours later, there will be 125 mg left, 10 more hours and there will be 62.5 mg left…
You get the picture.
Modafinil Has a Long Half-Life
Modafinil has a very long half-life compared to other drugs, such as Tylenol with a half-life of 2–3 hours, and caffeine with a half-life of 5–6 hours.
Some drugs, like Warfarin (a blood thinning medication), has a much longer half-life, which can range from 20–60 hours.
The Importance of Half-Life
We use information about the half-life of drugs to determine the dose of a medication, and how often it should be taken.
Tylenol, for example, needs to be taken every 3 or 4 hours for best results, while modafinil should only be taken once per day because its effects last much longer.
Adding Up Modafinil’s Half-Life to Figure Out How Long it Lasts:
A normal modafinil dose is about 200 mg.
We absorb only 40–65% of the modafinil into our bloodstream.
This means that we have about 80–130 mg in our bloodstream once it’s all absorbed.
Let’s go in the middle of this range and say that we absorb about 100 mg modafinil from the average 200 mg dose.
Since we know the half-life of modafinil is about 14 hours, this means that at the 14-hour mark we’ll have about 50 mg left in our system. We would still be feeling the effects at this dose, but they would be much weaker.
After 28 hours, we would then have 25 mg modafinil in our system, which we would likely no longer be feeling the effects of.
After 42 hours, we would still have about 12 mg of modafinil coursing around our bloodstream.
This would continue until there was nothing left. After 56 hours, 6 mg, 70 hours, 3 mg, 84 hours, 1.5 mg, 98 hours, less than 1 mg.
The takeaway from this is that with a 200 mg dose, based on the 14-hour half-life and 40-65% absorption rate of modafinil, the drug will produce effects for about 16-22 hours.
Piecing It All Together
Onset: 45 minutes to 2 hours
Time Until Peak Effects: 1–2 hours
Peak Effects: 2–4 Hours
Tapering Off Effects: 12–16 hours.
Total Duration Of Effects: 16–22 hours.
How Long Does Modafinil Stay in Your System?
Although the effects of modafinil usually disappear after about 16–22 hours, it can remain in the body for up to 4 days.
As mentioned, the body will still have about 1.5mg in the bloodstream 84 hours after taking it.
That’s 3 days later!
Therefore, it’s likely that the medication can be detected in the blood and urine for about 4 days after being taken
Changing How Long Modafinil Lasts
Some people look at the 16– 22-hour timeframe for modafinil and are either thinking that the 22-hour mark is too long, or the 16-hour mark is too short.
Although we can’t do too much to change the half-life of the drug, what we can do is push the duration to either side of this spectrum with a few tips and tricks.
To understand how this works, we need to first talk about how modafinil is metabolized in the body.
Consider How Modafinil is Metabolized
The liver is responsible for metabolizing modafinil.
Only about 10% of the modafinil can be found intact in the urine. This means that 90% of it is metabolized by the liver into an inactive compound, mainly modafinilic acid.
The liver is the ultimate filter for our bloodstream. It’s tasked with filtering and metabolizing compounds from our blood to make them either more water soluble so the kidneys can remove them, and change their chemical structure to make them less active.
The liver uses a complex system of enzymes in two separate phases to achieve this.
Modafinil is metabolized by a process called amide hydrolysis, and the cytochrome P450 isoenzymes (CYP450).
Modafinil is metabolized specifically by the CYP3A4 & CYP2C19 isoenzyme substrates, which is the main enzymes used for most drug metabolism.
Why is This Important?
Understanding which CYP450 enzymes is used by the liver to metabolize a particular medication is useful for identifying how a drug will respond in your body and gives us clues as to how to either increase or decrease the time a drug remains active in the body.
By taking other supplements that increase (induce) the activity of these CYP450 enzymes we can promote a faster metabolism of modafinil. This will, therefore, encourage a shorter duration of effects.
If we instead take supplements that inhibit these enzymes, we can slow the metabolism and therefore lengthen the duration of effects.
There are a lot of herbal supplements we can use for this.
How to Make Modafinil Last Less Time
Using CYP450 Inducers (Makes Modafinil Clear The System Quicker):
Inducing the CYP450 enzymes responsible for metabolizing modafinil will speed up the metabolism, helping it clear faster from the bloodstream.
This would make the duration of the effects shorter.
If your goal is to make modafinil last as long as possible you should avoid CYP450 inducers, especially pertaining to the 2C19 or 3A4 species.
Examples of CYP450 Inducers (3A4 & 2C19):
- Andrographis 
- Damiana 
- Dandelion root 
Bitter tasting foods also tend to increase the activity of the liver and therefore may increase the metabolic pathways through the CYP450 enzyme system.
How to Make Modafinil Last Longer
CYP450 Inhibitors (Makes Modafinil Last Longer)
Compounds that inhibit CYP450 enzymes will slow the metabolism of the drug, causing its effects to last longer.
Most substances that inhibit these enzymes do so by competitive metabolism.
Modafinil, for example, would be considered a CYP450 inhibitor because it is metabolized by the same enzymes.
If you want to make the effects of modafinil last longer, then you can use CYP450 inhibitors.
If you want the effects to be shorter in duration, be sure to avoid them.
Examples of CYP450 Inhibitors (3A4 & 2C19):
- Grapefruit juice (The real stuff, not grapefruit flavor) 
- Bacopa 
- Berberine-containing plants (like barberry, mahonia, or goldenseal) 
- Astragalus 
- California poppy 
- Cinnamon 
The effects of modafinil usually take about 45 minutes to an hour before they kick in, followed by about two hours of gradually increasing effects. By the 2nd or 3rd hour, the drug will be in full effect.
Over the next 12 to 16 hours the drug will start to wear off gradually. By hour 20, the drug is pretty much no longer active. However, it’s not uncommon for it to last about 22 hours total.
Modafinil can remain traceable in your system for the next 3 or 4 days.
There are ways to shorten or lengthen the effects of modafinil, mainly involving the use of herbs or supplements that either increase the rate of metabolism or slow it down.
- Wong, Y. N., King, S. P., Simcoe, D., Gorman, S., Laughton, W., McCormick, G. C., & Grebow, P. (1999). Open‐label, single‐dose pharmacokinetic study of modafinil tablets: influence of age and gender in normal subjects. The Journal of Clinical Pharmacology, 39(3), 281-288.
- Guo Y, Chen Y, Tan Z, Klaassen C. & Zhou H. (2012). Repeated Administration of Berberine Inhibits Cytochromes P450 in Humans.European Journal of Clinical Pharmacology, vol.68(2),p.213-217.
- Tassaneeyakul, W., Guo, L. Q., Fukuda, K., Ohta, T., & Yamazoe, Y. (2000). Inhibition selectivity of grapefruit juice components on human cytochromes P450. Archives of biochemistry and Biophysics, 378(2), 356-363.
- Ramasamy S, Kiew L. & Chung L. (2014). Inhibition of Human Cytochrome P450 Enzymes by Bacopa monnieri Standardized Extract and Constituents.Molecules, vol.19(2),p.2588-2601.
- Guo Y, Pope C, Cheng X, Zhou H. & Klaassen C. (2011). Dose-response of berberine on hepatic cytochromes P450 mRNA expression and activities in mice.Journal of Ethnopharmacology, vol.138(1),p.111-118.
- Lau C, Mooiman K, Maas-Bakker R, Beijnen J, Schellens J. & Meijerman I. (2013). Effect of Chinese Herbs on CYP3A4 Activity and Expression in vitro.Journal of Ethnopharmacology, vol, 49(2),p.543-549.
- Manda V, Ibrahim M, Dale O, Kumarihamy M, Cutler S, Khan I, Walker L, Muhammad I. & Khan S. (2016). Modulation of CYPs, P-gp, and PXR by Eschscholzia californica (California Poppy) and Its Alkaloids.Planta Medica, vol.82(6),p.551-558.
- Mamindla S, Koganti V, Ravouru N. & Koganti B. (2017). Effect of Cinnamomum cassia on the Pharmacokinetics and Pharmacodynamics of Pioglitazone.Current Clinical Pharmacology, vol.12(1),p.41-49.
- Hui H, Tang G. Go V. (2008). Hypoglycaemic Herbs and their Action Mechanisms: Review.Chinese Medicine, vol.4(11),p.1-11.
- Awortwe C, Bouic P, Masimirembwa C. & Rosenkranz B. (2014). Inhibition of Major Drug Metabolizing CYPs by Common Herbal Medicines used by HIV/AIDS Patients in Africa– Implications for Herb-Drug Interactions.Drug Metabolism Letters, vol.7(2),p.83-95.