Neuroscience Research Compound · For laboratory research use only
Also known as Fladrafinil, Fluorafinil, Bisfluoroadrafinil
CRL-40,941, also named fladrafinil, is 2-[bis(4-fluorophenyl)methylsulfinyl]-N-hydroxyacetamide: a bis(4-fluorophenyl) analogue of adrafinil and a structural analogue of modafinil1,2. Its non-hydroxylated counterpart is CRL-40,940 (flmodafinil)2.
Published research on fladrafinil is very limited. The peer-reviewed studies indexed on PubMed are analytical: one characterised its thermal degradation during gas chromatography, and one examined its metabolism and elimination for sports drug testing1,2. No primary pharmacology studies in cell or animal models were found.
As described in the research literature
The mechanism of fladrafinil has not been characterised in published primary studies. A 2026 analytical study described it as a prodrug of flmodafinil: in samples collected after fladrafinil, flmodafinil and its acid and sulfone metabolites were detected in urine and dried blood spot samples, with a delay in the flmodafinil peak attributed to conversion of the prodrug2.
The same study notes that flmodafinil and fladrafinil are listed by the World Anti-Doping Agency under class S6 stimulants, prohibited in competition2.
What published studies have examined
Thermal degradation in the heated inlet of a gas chromatograph was examined for modafinil, modafinic acid, adrafinil, CRL-40,940 and CRL-40,941 dissolved in a range of solvents. The fluorinated compounds formed a fluorinated analogue of 1,1,2,2-tetraphenylethane, and the parent compounds were characterised by 1H and 13C NMR1.
Sources [1]
An anti-doping study used LC-HRMS to characterise the elimination profiles of flmodafinil, fladrafinil and their metabolites (flmodafinil acid and flmodafinil sulfone) in urine and dried blood spots, and to establish detection limits2.
Sources [2]
Outsmarted by nootropics? An investigation into the thermal degradation of modafinil, modafinic acid, adrafinil, CRL-40,940 and CRL-40,941 in the GC injector: formation of 1,1,2,2-tetraphenylethane and its tetra fluoro analog.
Dowling G, Kavanagh PV, Talbot B, et al. Drug Testing and Analysis, 2017.
Investigations Into the Metabolism and Elimination of Flmodafinil and Fladrafinil for Sports Drug Testing Purposes.
Krug O, Guddat S, Görgens C, et al. Drug Testing and Analysis, 2026.
This page is provided for research and educational reference only. It does not constitute medical advice, dosing guidance, or a recommendation for use. All compounds are strictly for laboratory and in-vitro research purposes.