How? How much? When? For how long?
As with any drug, the correct dose for you depends on factors such as weight,
gender, metabolism, whether you have taken the drug recently or not, amongst
Please read our secion on dosing and tolerance in ME for
Modafinil has two sibling drugs that work in exactly the same way;
Armodafinil and Adrafinil. Their chemical differences are explained below.
In terms of usage, there are a number of subtle differences between these
three forms. For most purposes modafinil, as the most studied form, is the
best option. However armodafinil is essentially a more potent form of the
same active chemical, and so can be considered as equivalent.. Adrafinil on
the other hand is tougher on the body and has not been studied anywhere near
as much. As such, there may be undiscovered risks. The main reason behind its
popularity is that in most countries where is is illegal to obtain modafinil
without a prescription, adrafinil is not a controlled substance and can be
Modafinil: The classic drug.
Because of how modafinil works in the body, only half of the drug will be in
the correct chemical structure to produce an effect on your body. Armodafinil
is the purified form of this correct “R” structure, and so is slightly
stronger than modafinil. It is also processed by the body a little bit less
slowly than modafinil, though not by much.
Once ingested this drug is processed by the liver to produce modafinil. Since
it needs to be broken down to become active, it takes slightly longer for
adrafinil to take effect and the effects will also last for longer. Adrafinil
is also less potent than modafinil.
How you take it matters...
However you take modafinil, the main thing to consider is the duration of
effects (up to 20 hours!). Make sure you dose as early as possible; as soon
as you wake up, and never after midday. Unless you are planning on staying
up all night, which we don’t recommend as it will affect your sleep cycle and
have knock-on effects on your health.
To reduce the duration of action, most people take modafinil sublingually
(by placing it under the tongue), or by swallowing the pill on an empty
stomach. This allows quick absorption.
Which is best is mainly down to personal preference; modafinil tastes
extremely bitter and can be difficult to keep under the tongue, but taking
modafinil on an empty stomach can worsen the stomach upset and nausea.
N.B. When dosing by splitting up a standard pill, there is a chance that the
active drug is not evenly spread throughout the pill (the majority of a pill
is made up of harmless filler substances). To better control dosage, some
people like to crush up the pill and dissolve it in water, and then drinking
their desired dose.
There are reports of users
crushing modafinil pills and snorting them. There
are no real benefits to this; modafinil is already absorbed quickly if placed
under the tongue, while the filler in a pill of modafinil will produce enough
powder to block your nose, which would be a somewhat unpleasant experience.
How much? When? And how long?
With the modafinil family, we recommend you start low and work your way up (see
titration dosing for advice)
but be very wary of the long duration and remember your sleep debt will return
once the drug wears off. Typically, higher doses are required by people who
typically are experienced with stimulants, and people with higher body mass.
Half-life: This is the time taken for your body to breakdown
half of the drug. It can be used as an indicator of how long the effects will
last for; however it is not the duration of action as half of the active drug
will remain in your body.
How much?: If you are trying to get rid of fatigue,
then as little as 25-50 mg can be effective. If you are seeking the
stimulant effects of modafinil, then it is more common to use a dose
How long?: Your body is able to break down half of the
drug in about 16 hours; this is another reason why we recommend starting
low. A 200 mg dose will wear off after about 20 hours.
- How much?: A 200 mg dose of Modafinil corresponds to between 100-150 mg of Armodafinil
- How long?: Slightly shorter than modafinil; half the drug is cleared in 13-14 hours compared to 16.
- How much?: A standard dose is between 600-1000 mg.
- How long?: 22-24 hours. It takes an hour for half of the adrafinil taken to be converted into modafinil, which in turn has effects lasting at least 20 hours.
When do the effects kick in and for how long?
Studies looking at the long-term safety of modafinil in people with narcolepsy have shown the drug to be safe in daily use. However we recommend at least alternating days, and rather using the drug rarely when you really require extra stimulation. After consecutive days of dosing, the enhancing effects seem to be reduced. This could due to poorly understood effects on sleep as modafinil builds up in the system. Tolerance also develops over time, leading to a number of "cycling" regimens where people take breaks to restore their sensitivity to the drug.
Also worth considering for long-term use is the potential effects on relying on a drug to be productive. There are a number of sites which discuss this , and just as some people are hesitant, others have had great experiences with modafinil and liken its use to that of caffeine. We recommend you read more and make up your own mind.