Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of (S)-CE-123 and Fladrafinil — mechanism, side effects, legal status, and pricing.
(S)-CE-123 is a non-peptide small molecule belonging to the diphenylmethyl-sulfinyl-thiazole chemotype, structurally related to modafinil. It acts as an atypical, non-releasing dopamine transporter (DAT) inhibitor—blocking dopamine reuptake without triggering amphetamine-like transporter-mediated release. No human clinical data exist; all pharmacology, behavioral, and pharmacokinetic findings are preclinical (rodent in vivo and human-liver-microsome/HEK293-cell in vitro). The compound is not individually named on WADA's current Prohibited List, though modafinil (the parent compound) is a named S6 stimulant; no authoritative WADA ruling specific to CE-123 was found.
Fladrafinil (CRL-40,941) is a non-peptide synthetic eugeroic and the bis(4-fluorophenyl)-substituted analog of adrafinil, retaining adrafinil's N-hydroxyacetamide group. Never approved or marketed as a pharmaceutical in any jurisdiction, it is sold exclusively as an unregulated research chemical. Added to WADA's S6 (Stimulants, non-specified) category on the 2026 Prohibited List, effective 1 January 2026.
(S)-CE-123
Fladrafinil
Category
Legal Status
Mechanism
Side Effects
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
(S)-CE-123
No pricing data yet.
Check (S)-CE-123 prices →Fladrafinil
No pricing data yet.
Check Fladrafinil prices →COA corpus from Disclosed Labs — independently tested batches only.
(S)-CE-123
2
COAs
99.9%
Avg purity
2
Labs
Fladrafinil
2
COAs
99.6%
Avg purity
1
Labs
No human data exist for (S)-CE-123. No registered ClinicalTrials.gov trials or DrugBank entries were found, and the primary source explicitly states that no human data are available. All pharmacology and behavioral data are preclinical. In rats, (S)-CE-123 at 24.0 mg/kg i.p. partially reversed tetrabenazine-induced deficits in effort-based lever pressing, increased progressive-ratio responding, and raised extracellular dopamine in the nucleus accumbens core. At 0.3–1.0 mg/kg i.p., CE-123 improved extra-dimensional set-shifting in an attentional task without the impulsivity-increasing effects observed with R-modafinil at 10 mg/kg. Daily dosing improved spatial memory acquisition and retrieval in a hole-board task and ameliorated maternal-separation-induced spatial learning deficits in adolescent rats, with sex-dependent effects. Pharmacokinetic studies in rats and human liver microsomes show that S-CE-123 achieves ~5-fold greater unbound brain penetration (Kp,uu,brain = 0.5) than R-modafinil but is metabolized 9.3-fold faster in human liver microsomes (t₁/₂ 39 min vs. 364 min).
Key references
No clinical trials for any therapeutic indication exist; no FDA approval has been granted. The only identified human data are: (1) a 2026 peer-reviewed pharmacokinetics/metabolism study for anti-doping purposes (Krug et al., Drug Testing and Analysis), which administered fladrafinil orally to healthy volunteers and confirmed metabolism to flmodafinil, flmodafinil acid, and flmodafinil sulfone; and (2) unverified patent-holder claims from 1984 describing oral 50 mg capsules for hypersomnia/psychasthenia with reported 'excellent results' over 2–8 weeks—this is not an independently published or peer-reviewed trial. Animal studies (mice/rats, intraperitoneal, 16–256 mg/kg) from the 1984 Lafon patent reported reduced barbiturate-induced sleep duration, increased spontaneous motor activity, reduced inter-group aggression, improved motor recovery following hypoxic stress, and prolonged amphetamine-induced stereotypy.
(S)-CE-123 and Fladrafinil are both in the Cognitive category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Contraindications
Lab Testing
Disclosed Labs