Armodafinil vs Modafinil: Which Is Stronger?

Science · 9 min read · Feb 18, 2026

Armodafinil and modafinil are closely related — armodafinil is literally derived from modafinil. But they behave differently in practice, and "stronger" depends on what you mean. Here is a thorough comparison to help you choose.

The Chemistry: What Is the Difference?

Modafinil is a racemic compound — it contains two mirror-image molecules (enantiomers) in equal parts: R-modafinil and S-modafinil. Armodafinil contains only the R-enantiomer, which is the pharmacologically more active form.

Think of it like this: modafinil is a 50/50 mix of active and less-active molecules. Armodafinil is a purified version containing only the more active molecule. This is why armodafinil is effective at a lower milligram dose — there is no inactive filler diluting it.

Dosing: Milligram for Milligram Comparison

Due to the enantiomer difference, dose equivalence is approximately:

This means armodafinil is more potent by weight, but not necessarily "stronger" in terms of peak effect — it is more efficient.

Duration and Plasma Levels

This is where armodafinil meaningfully differs from modafinil. Clinical pharmacokinetic studies show:

In practice this means armodafinil tends to feel more consistent throughout the day, without the mid-afternoon dip some people notice with modafinil. The flip side: armodafinil's later-day presence makes evening insomnia more likely if dosed too late.

Subjective Effects: How They Feel Differently

User reports consistently describe some differences in the quality of effects:

Modafinil (Modalert, Modvigil)

Armodafinil (Waklert, Artvigil)

Side Effect Profile

Both compounds share the same side effect profile — headache, nausea, dry mouth, insomnia, reduced appetite. The differences are subtle:

Brand Names and Generic Options

Both are available as branded pharmaceuticals and as Indian generics:

Among generics, Modalert and Waklert are considered the premium options from Sun Pharma, while Modvigil and Artvigil from HAB Pharma are solid budget alternatives.

Which Should You Choose?

There is no universal right answer — it depends on your use case:

Disclaimer: Both modafinil and armodafinil are prescription medications. This article is for educational purposes only. Consult a healthcare professional before using either compound.

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