Fladrafinil (CRL-40,941)
NootropicsPreclinicalAlso known as: CRL-40,941, CRL 40941, Fluorafinil, Bisfluoroadrafinil, 2-[bis(4-fluorophenyl)methylsulfinyl]-N-hydroxyacetamide
Fladrafinil, coded CRL-40,941, is the N-hydroxy analog of flmodafinil and the difluorinated counterpart of adrafinil. Flmodafinil was conceived at Laboratoire L.
Overview
At A Glance
Fladrafinil is the N-hydroxy analog of flmodafinil and behaves as a prodrug: after oral administration to humans it is converted to flmodafinil, which is then oxidized to the inactive derivatives flmodafinil acid and flmodafinil sulfone, mirroring the way adrafinil is converted t…
Overview
Fladrafinil, coded CRL-40,941, is the N-hydroxy analog of flmodafinil and the difluorinated counterpart of adrafinil. Flmodafinil was conceived at Laboratoire L. Lafon, the French company behind adrafinil and modafinil, and was never developed as a medicine (PMID: 30158846); the CRL-40,941 code of fladrafinil places it in the same series. Fladrafinil is sold today only as a research chemical or as an ingredient in unapproved supplements marketed for wakefulness and focus, and interest in it grew alongside the off-label use of modafinil as a cognitive enhancer (PMID: 27928893). Its pharmacology is best understood as prodrug chemistry. In a human administration study published in 2026, six volunteers each took a single 20 mg dose and gave urine and dried blood spot samples; fladrafinil was converted to flmodafinil, which was then oxidized to flmodafinil acid and flmodafinil sulfone, the same pattern adrafinil follows toward modafinil (PMID: 42210629). The activity therefore belongs mostly to flmodafinil rather than to the parent compound. For flmodafinil there is one useful animal study, published under the compound names lauflumide and NLS-4. In male C57BL/6J mice with EEG and EMG recording, an intraperitoneal dose of 64 mg/kg produced longer wakefulness than modafinil at 150 mg/kg, without hyperlocomotion and without rebound hypersomnia, and recovery sleep afterwards involved less non-REM sleep and less delta activity than after modafinil (PMID: 30158846). No comparable study exists for fladrafinil itself. Nothing about efficacy in people has been tested. The single human study measured concentrations and detection windows, not attention, wakefulness or performance (PMID: 42210629). For the class parent, positron emission tomography in ten healthy men showed that modafinil occupied dopamine transporters in caudate, putamen and nucleus accumbens and raised extracellular dopamine, a finding the authors linked to abuse potential (PMID: 19293415). Whether the fluorinated analogs behave the same way at the same exposures has not been measured in humans. Two practical points come out of the doping-control work. Product labels are unreliable: one supplement bought for that study was labeled at 50 mg/mL of flmodafinil and assayed at 95.7 mg/mL, close to double the stated content (PMID: 42210629). And anyone tested in sport should know that fladrafinil and flmodafinil were added to the 2026 World Anti-Doping Agency Prohibited List under class S6 stimulants and are prohibited in competition, with detection windows of up to a week for the parent compounds and about two weeks for the metabolites (PMID: 42210629). A retrospective screen of about 2000 in-competition samples collected in 2023 and 2024 found none of these compounds, so current use among tested athletes appears low. There is no FDA or EMA authorization for fladrafinil, no published safety trial, and no pregnancy, cardiac or hepatic data. It is a research-use-only compound in the US market, and the gap between what is claimed for it online and what has actually been measured is wide.
Potential Research Fields
Chemical Information
IUPAC Name
Not yet available
CAS Number
90212-80-9
Molecular Formula
C15H13F2NO3S
Molecular Mass
325.3 g/mol
Dosing & Protocols
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Interactions
Contraindications
Mechanism-based: fladrafinil is converted to a compound of the modafinil class, and modafinil occupies dopamine transporters and raises brain dopamine in humans, an effect the investigators linked to abuse potential in vulnerable people (PMID: 19293415). Athletes subject to anti-doping testing should treat it as prohibited in competition (PMID: 42210629). No pregnancy, hepatic or cardiac safety data exist for fladrafinil in any species.
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This interaction data is compiled from published research and community reports. It may not be exhaustive. Always consult a healthcare professional before combining compounds.
$74.99
$0.0250
1
1
liquid
| Vendor | Product | Form | Qty | Price | $/mg | Coupon | |
|---|---|---|---|---|---|---|---|
 |
Fladrafinil 100 mg/mL, 30 mL | liquid | 30 mL (100 mg/mL)● In Stock | $74.99BEST | $0.025 | — |
Tracking since Sep 7, 2026 · 1 data point
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Related Compounds
View All9-Me-BC (9-Methyl-β-carboline)
NootropicsPreclinical9-Methyl--carboline (9-Me-BC) is a synthetic -carboline alkaloid that has drawn nootropic-community interest for a preclinical property that is genuinely unusual among -carbolines: in rodent and cell-culture studies it appears to stimulate the dopaminergic phenotype - raising tyrosine hydroxylase, the number of differentiated dopamine neurons and dopamine content - while also showing neuroprotective, neurorestorative and anti-inflammatory effects, plus in-vitro MAO-A/MAO-B inhibition [PMID:17913302, PMID:20374418, PMID:32285253].
Aniracetam
NootropicsApproved (Italy)Aniracetam is a pyrrolidinone in the racetam family, developed by Hoffmann-La Roche under the code Ro 13-5057.
Bemethyl (bemitil)
NootropicsApproved (Russia)Bemethyl, known in the Russian literature as bemitil and sold in the region under names including Metaprot, Bemactor and Antihot, is 2-ethylthiobenzimidazole, normally handled as the hydrobromide salt.
Bromantane
NootropicsRussia ApprovedBromantane is an atypical psychostimulant and anxiolytic developed in the 1980s at the Zakusov Institute of Pharmacology of the Russian Academy of Medical Sciences, originally created as an adaptogen for Soviet military and elite athletic use and later approved in Russia for the treatment of neurasthenic and asthenic disorders under the trade name Ladasten.
Cyclazodone
NootropicsPreclinicalCyclazodone is the N-cyclopropyl derivative of pemoline, a 4-oxazolidinone stimulant.
Dihexa
NootropicsPreclinicalDihexa is a synthetic peptide analogue of the angiotensin IV metabolite LVV-hemorphin-7, developed at Washington State University.
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Protocols, calculator & safety for Fladrafinil (CRL-40,941)
Research Score
0 PubMed studies
Quality Indicators
Data Completeness
63%Quick Facts
Half-Life
Not established in humans; after a single 20 mg oral dose in six volunteers, urinary fladrafinil peaked at 2 to 4 h and stayed detectable for up to 12 h, while the metabolite flmodafinil was detectable for about 8 days and the acid and sulfone metabolites for about two weeks (PMID: 42210629)
Molecular Weight
325.3 g/mol
Administration
Oral
CAS Number
90212-80-9
Trial Phase
Preclinical
Research Disclaimer
This information is for educational and research purposes only. Not intended as medical advice. Consult a healthcare professional before use.
Frequently Asked Questions
What is Fladrafinil (CRL-40,941) used for in research?
Fladrafinil, coded CRL-40,941, is the N-hydroxy analog of flmodafinil and the difluorinated counterpart of adrafinil. Flmodafinil was conceived at Laboratoire L. Lafon, the French company behind adrafinil and modafinil, and was never developed as a medicine (PMID: 30158846); the CRL-40,941 code of fladrafinil places it in the same series. Fladrafinil is sold today only as a research chemical or as an ingredient in unapproved supplements marketed for wakefulness and focus, and interest in it grew alongside the off-label use of modafinil as a cognitive enhancer (PMID: 27928893).
Its pharmacology is best understood as prodrug chemistry. In a human administration study published in 2026, six volunteers each took a single 20 mg dose and gave urine and dried blood spot samples; fladrafinil was converted to flmodafinil, which was then oxidized to flmodafinil acid and flmodafinil sulfone, the same pattern adrafinil follows toward modafinil (PMID: 42210629). The activity therefore belongs mostly to flmodafinil rather than to the parent compound.
For flmodafinil there is one useful animal study, published under the compound names lauflumide and NLS-4. In male C57BL/6J mice with EEG and EMG recording, an intraperitoneal dose of 64 mg/kg produced longer wakefulness than modafinil at 150 mg/kg, without hyperlocomotion and without rebound hypersomnia, and recovery sleep afterwards involved less non-REM sleep and less delta activity than after modafinil (PMID: 30158846). No comparable study exists for fladrafinil itself.
Nothing about efficacy in people has been tested. The single human study measured concentrations and detection windows, not attention, wakefulness or performance (PMID: 42210629). For the class parent, positron emission tomography in ten healthy men showed that modafinil occupied dopamine transporters in caudate, putamen and nucleus accumbens and raised extracellular dopamine, a finding the authors linked to abuse potential (PMID: 19293415). Whether the fluorinated analogs behave the same way at the same exposures has not been measured in humans.
Two practical points come out of the doping-control work. Product labels are unreliable: one supplement bought for that study was labeled at 50 mg/mL of flmodafinil and assayed at 95.7 mg/mL, close to double the stated content (PMID: 42210629). And anyone tested in sport should know that fladrafinil and flmodafinil were added to the 2026 World Anti-Doping Agency Prohibited List under class S6 stimulants and are prohibited in competition, with detection windows of up to a week for the parent compounds and about two weeks for the metabolites (PMID: 42210629). A retrospective screen of about 2000 in-competition samples collected in 2023 and 2024 found none of these compounds, so current use among tested athletes appears low.
There is no FDA or EMA authorization for fladrafinil, no published safety trial, and no pregnancy, cardiac or hepatic data. It is a research-use-only compound in the US market, and the gap between what is claimed for it online and what has actually been measured is wide.
What forms does Fladrafinil (CRL-40,941) come in?
Fladrafinil (CRL-40,941) is available in liquid form.
How much does Fladrafinil (CRL-40,941) cost?
Prices start at $74.99 across 1 verified vendor.
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Research Tools
Related Compounds
View All9-Me-BC (9-Methyl-β-carboline)
NootropicsPreclinical9-Methyl--carboline (9-Me-BC) is a synthetic -carboline alkaloid that has drawn nootropic-community interest for a preclinical property that is genuinely unusual among -carbolines: in rodent and cell-culture studies it appears to stimulate the dopaminergic phenotype - raising tyrosine hydroxylase, the number of differentiated dopamine neurons and dopamine content - while also showing neuroprotective, neurorestorative and anti-inflammatory effects, plus in-vitro MAO-A/MAO-B inhibition [PMID:17913302, PMID:20374418, PMID:32285253].
Aniracetam
NootropicsApproved (Italy)Aniracetam is a pyrrolidinone in the racetam family, developed by Hoffmann-La Roche under the code Ro 13-5057.
Bemethyl (bemitil)
NootropicsApproved (Russia)Bemethyl, known in the Russian literature as bemitil and sold in the region under names including Metaprot, Bemactor and Antihot, is 2-ethylthiobenzimidazole, normally handled as the hydrobromide salt.
Bromantane
NootropicsRussia ApprovedBromantane is an atypical psychostimulant and anxiolytic developed in the 1980s at the Zakusov Institute of Pharmacology of the Russian Academy of Medical Sciences, originally created as an adaptogen for Soviet military and elite athletic use and later approved in Russia for the treatment of neurasthenic and asthenic disorders under the trade name Ladasten.
Cyclazodone
NootropicsPreclinicalCyclazodone is the N-cyclopropyl derivative of pemoline, a 4-oxazolidinone stimulant.
Dihexa
NootropicsPreclinicalDihexa is a synthetic peptide analogue of the angiotensin IV metabolite LVV-hemorphin-7, developed at Washington State University.
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