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 Adrafinil and Hydrafinil (9-Fluorenol) — mechanism, side effects, legal status, and pricing.
Adrafinil is a non-peptide synthetic eugeroic (wakefulness-promoting agent) and diphenylmethylsulfinyl-acetohydroxamic acid derivative that functions as a prodrug of modafinil. It was approved in France (marketed as Olmifon) from 1984 to 2011 for narcolepsy but was voluntarily withdrawn due to hepatotoxicity concerns and an unfavorable risk-benefit ratio. Adrafinil is not currently approved in any jurisdiction; the FDA classifies it as an unapproved new drug when sold as a dietary supplement. It is prohibited in competitive sport under WADA’s S6.a Non-Specified Stimulants category.
Hydrafinil (9-fluorenol) is a non-peptide fluorene derivative and secondary benzylic alcohol (C₁₃H₁₀O, MW 182.22) investigated as a potential wakefulness-promoting agent structurally distinct from modafinil's diphenylmethyl-sulfinyl scaffold. It has no approved human indication and is not FDA-approved or approved by any regulatory body for human or veterinary use. Hydrafinil is listed as an S6.A Non-Specified Stimulant on the WADA Prohibited List; Section S6.A stimulants are prohibited in-competition only, so it is banned in-competition and athletes are subject to strict liability. It is sold online by research-chemical vendors for laboratory use only, not for human consumption.
Adrafinil
Hydrafinil (9-Fluorenol)
Category
Legal Status
Mechanism
Side Effects
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Adrafinil
No pricing data yet.
Check Adrafinil prices →Hydrafinil (9-Fluorenol)
No pricing data yet.
Check Hydrafinil (9-Fluorenol) prices →COA corpus from Disclosed Labs — independently tested batches only.
Adrafinil
3
COAs
99.8%
Avg purity
2
Labs
Hydrafinil (9-Fluorenol)
2
COAs
99.0%
Avg purity
1
Labs
Adrafinil was approved in France for narcolepsy (1985) after initial human testing in 1977–1978, but was voluntarily withdrawn in September 2011 due to hepatotoxicity concerns and an unfavorable risk-benefit ratio. No current registered interventional clinical trials exist; the only registered study is an observational survey listing adrafinil as a queried substance. One published forensic study (n=1) detected adrafinil (0.8 ng/mg) and modafinil (0.5 ng/mg) in beard hair 10 days after a single 200 mg oral dose in one adult volunteer. Preclinical studies in aged beagle dogs found oral 20 mg/kg adrafinil improved discrimination learning but impaired working memory in a delayed nonmatching-to-position task over 8 days. Rat studies of the metabolite modafinil showed dose-dependent increases in locomotor activity and extracellular dopamine.
Key references
No human efficacy or safety trials have been conducted. The only human data is a 2021 pilot pharmacokinetic/analytical study (Knoop et al., PMID 34378339) in which three healthy male volunteers received a single 50 mg oral dose of hydrafinil, with urine collected up to 72 hours post-dose to characterize Phase I/II metabolites (hydroxylated, glucuronidated, sulfo-conjugated) for anti-doping detection purposes; this study was designed solely for metabolite identification and does not establish safety, efficacy, or a validated dose. In rats, a Cephalon Inc. drug-discovery program screened fluorene-derived compounds as candidate next-generation modafinil agents; one analog ('compound 15') showed wake-promoting activity attributed to an active metabolite ('compound 3'), though the published abstract does not confirm compound 3's identity as fluorenol or provide potency data.
Adrafinil and Hydrafinil (9-Fluorenol) 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