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Synthetic nootropics & research compounds

Fluoromodafinil

Fluoromodafinil (flmodafinil; CRL-40,940)

Fluoromodafinil, also called flmodafinil or CRL-40,940, is a modafinil analogue with very limited direct human research. It is not an established treatment or a validated cognitive enhancer, and its safety, interactions, and long-term effects are not established.

SyntheticClinical ResearchInsufficient EvidenceHigh Risk ProfileLong Term Safety UnknownLegal Caution
Updated August 2026/4 min read/3 citations
Reviewed by the NootropicsIndex editorial team.Method: prioritize cited human research and official safety or regulatory sources; compare retailer-listed prices without endorsing products.Affiliate disclosure
Extra caution

Who should avoid this or get expert review first

This is not a recommendation to use. These groups should treat the profile as a reason to slow down and verify safety, rules, and personal context.

  • Avoid self-directed use1Because clinical efficacy, safety, interactions, and product quality are not established, do not self-direct fluoromodafinil use for studying, fatigue, shift work, sport, or a health condition. Seek care for persistent sleepiness, fatigue, or concentration problems rather than self-directing use of an unvalidated analogue.
01

What is it?

What fluoromodafinil refers to

1

Fluoromodafinil commonly refers to flmodafinil (CRL-40,940), a structural analogue of modafinil. The cited human study identifies it as 2-[bis(4-fluorophenyl)methylsulfinyl]acetamide.

Research compound, not a validated nootropic1
This page does not present fluoromodafinil as a dietary supplement, medicine, or validated cognitive enhancer. The direct human study did not assess therapeutic benefit or establish a safe regimen; analogies to modafinil do not establish comparable benefits, safety, or quality.

What the direct human study measured

1

A 2026 sports-testing study gave six volunteers a single 20 mg research exposure to flmodafinil or fladrafinil and measured drugs and metabolites in urine and blood. It was designed for metabolism and detection research, not to test clinical benefit or establish a safe regimen.

02

Names, aliases and forms

Research CodeCRL-40,940
Common NameFlmodafinil
Chemical NameBisfluoromodafinil
03

Mechanisms of action

Mechanism and benefit remain unestablished

1

The reviewed direct human source characterises chemical identity and metabolism, not a clinical mechanism of benefit. Claims about focus, wakefulness, or productivity should not be inferred from modafinil or from anti-doping classification.

04

Potential effects and evidence map

A 2026 study examined metabolism and elimination after a single research exposure in six volunteers; it did not establish clinical efficacy, a therapeutic regimen, or long-term safety. Wakefulness and cognitive claims should not be extrapolated from modafinil or this analytical study.

Effect domainMagnitudeGrade
Mental energy / wakefulness1
UnknownConfidence: Low

No direct clinical efficacy evidence establishes fluoromodafinil for wakefulness, attention, fatigue, or cognitive enhancement.

Note The cited six-volunteer study measured metabolism and elimination, not an efficacy outcome.

0/5
E
05

Typical dosages and timing

Clinical regimen1Not established

The 20 mg amount in the cited study was an analytical research protocol, not a recommended dose. No clinical regimen, titration plan, or self-use schedule is provided here.

06

Timing & effect horizon

Effect horizonUnknown
Unknown
No user-facing timing profile1

The metabolism study supports anti-doping detection research, but it does not establish onset, duration, washout, or timing for personal use. Detection findings should not be used to plan use or evade testing.

07

Safety, side effects and risk profile

Evidence uncertainty1
Confidence: High

Direct data are too limited to characterize a safe use pattern, long-term effects, or an individual adverse-effect profile.

Note The available human study was an analytical metabolism protocol in six volunteers, not a safety trial.

4/5
E
Legal / regulatory risk2
Confidence: High

Sports and legal rules are jurisdiction- and context-specific; WADA prohibits flmodafinil in competition in 2026.

Note Anti-doping status is distinct from product approval, scheduling, import, or possession law.

4/5
E
Safety data are insufficient1

The limited direct human data do not define an individual adverse-effect profile, interaction pattern, contraindications, pregnancy safety, or long-term safety. Modafinil safety information cannot be assumed to apply to fluoromodafinil.

08

Interactions and cautions

Interaction compatibility is unknown1

No direct evidence reviewed here establishes compatible combinations with prescription medicines, alcohol, stimulants, supplements, or other substances. Do not infer interaction safety from modafinil or from a seller description.

09

Legal and regulatory status

Anti-doping status in 20262

As of 2026, under the World Anti-Doping Agency rules for WADA-governed sport, flmodafinil is an S6.A non-specified stimulant prohibited in competition. In the United States, this sports rule is distinct from FDA product approval and is not a statement of general product legality or medical approval.

United States regulatory context3

As of the FDA's 2023 analytical-method poster, bisfluoromodafinil (CRL-40,940) was included among unscheduled modafinil analogues studied by the agency. Product approval, scheduling, import, possession, and food-supplement rules can change and are jurisdiction-specific; this dated source is not current legal advice.

10

Practical buying and quality notes

  • No fluoromodafinil offers are currently mapped on NootropicsIndex. This page does not recommend sellers or suggest that labels, purity documents, or online availability establish identity, safety, or lawful use.3
11

FAQ

Is fluoromodafinil the same as modafinil?

1

No. It is a fluorinated structural analogue. Evidence or prescribing information for modafinil does not validate fluoromodafinil for the same uses or establish comparable safety.

Can an athlete use fluoromodafinil in competition?

2

No. The 2026 WADA Prohibited List names flmodafinil in S6.A, the stimulant category prohibited in competition. Athletes should use their sport body's current rules and medical process rather than this page to assess compliance.

12

References

  1. Krug O, Guddat S, Gorgens C, et al. Investigations Into the Metabolism and Elimination of Flmodafinil and Fladrafinil for Sports Drug Testing Purposes. Drug Testing and Analysis. 2026.
  2. World Anti-Doping Agency. 2026 Prohibited List and explanatory note.
  3. U.S. Food and Drug Administration. Development and Validation of an Analytical Method to Identify and Quantitate Novel Modafinil Analogs in Dietary Supplements.
Note

This page is informational and summarizes available evidence. It is not medical advice, a recommendation, or a substitute for guidance from a qualified clinician.