Methylnaphthidate

Methylnaphthidate is expressly listed in Schedule III item 2(7) with its exact methyl 2-(naphthalen-2-yl)-2-(piperidin-2-yl)acetate identity. Unauthorized possession, trafficking, import, export, and production are prohibited, subject to regulatory authorization and statutory exemptions.

Making or importing it with the intent of putting it on the market, administering it to someone else, and trading it are punishable. Possession remains unlawful, but is not penalized.

Methylnaphthidate (HDMP-28; methyl 2-(naphthalen-2-yl)-2-(piperidin-2-yl)acetate) is structurally covered by List IA Group 1 and is not an exact-name List I listing. PubChem identifies the substance as a 2-naphthyl compound bearing a piperidin-2-yl group and methyl ester. Group 1 expressly permits naphthyl as structural element A, permits piperidinyl where nitrogen is integral to a ring system in structural element B, and permits alkoxycarbonyl substitution at C1/C2; the specified structure therefore matches the group definition. Current Article 2a(1) prohibits import/export, preparation, processing, sale, supply, transport, possession, and manufacture of a List IA-group substance or its preparation. Article 2a(2) excludes specified authorised medicinal products and regulated operators, listed precursor substances, and List I/II means; Article 6(3) provides a limited exemption route.

Act 14 of 2022 substituted the current Schedule 2. Part II is headed ‘DANGEROUS DEPENDENCE-PRODUCING SUBSTANCES’ and expressly lists ‘Methylphenidate and the derivatives thereof.’ Part II paragraph 2(e) additionally includes, unless expressly excluded or separately listed in Schedule 2, ‘all homologues’, defined as chemically related substances that incorporate a structural fragment similar to a listed substance or exhibit similar pharmacodynamic properties. PubChem identifies methylnaphthidate/HDMP-28 as methyl (2R)-2-naphthalen-2-yl-2-[(2R)-piperidin-2-yl]acetate and methylphenidate as methyl 2-phenyl-2-piperidin-2-ylacetate; their published connectivity SMILES show the shared methyl 2-(piperidin-2-yl)acetate scaffold, with methylnaphthidate differing by a naphthalen-2-yl rather than phenyl substituent. Under the statute's structural-fragment definition, methylnaphthidate is a Part II homologue. Sections 4(b) and 5(b) prohibit use/possession and dealing, respectively, in a dangerous dependence-producing substance, subject to the Act's statutory medical/acquisition and authorization exceptions. Methylnaphthidate is not separately named, but the Part II homologue provision covers it.

The current consolidated regulation (amended through SFS 2026:1109) expressly lists metyl-naftalen-2-yl(piperidin-2-yl)acetat (metylnaftidat, HDMP-28) in Bilaga 1, rather than relying on methylphenidate or an inferred phenidate analogue. Under regulation 2 §, Bilaga 1 substances are narcotics under the Narcotic Drugs Penal Act. Unauthorized transfer; manufacture intended for misuse; acquisition for transfer; non-personal procurement, processing, packaging, transport, storage or similar handling; and possession, use or other handling are offences under Penal Act 1 §; unauthorized import/export is addressed by the Smuggling Act. The Control of Narcotics Act confines import/export, manufacture, offering for sale, transfer and possession to medical, scientific, specially important societal, or specified/excepted industrial purposes, with permits and enumerated exceptions/authorizations (including a narrow traveller rule for narcotic medicines for personal medical use).

Decision No. 2016/8548 expressly lists HDMP-28 as methyl (2R)-2-naphthyl [(2R)-piperidin-2-yl]acetate and subjects it to Law No. 2313 on the Control of Narcotic Drugs. The decision entered into force upon publication on 8 March 2016. Law No. 2313 regulates import, export, and domestic sale, and article 20 requires seizure when covered substances are imported or sold without authorization or held by a person lacking legal authority.

Methylnaphthidate is expressly listed by the synonym HDMP-28 (метилнафтидат), with the chemical name methyl 2-(2-naphthyl)-2-(2-piperidyl)acetate. It is a direct exact-structure listing, not a methylphenidate or analogue inference, in Table I List No. 2 of Ukraine's current controlled-substances schedule.

Under United States federal law, the DEA alphabetical controlled-substances list dated August 27, 2026 does not separately name methylnaphthidate or HDMP-28, although DEA states that the list is not comprehensive and that an unlisted substance may still be treated as scheduled or regulated as a controlled substance analogue. Potential analogue treatment is case- and conduct-specific: 21 U.S.C. § 802(32) requires proof of substantial structural similarity to a Schedule I or II controlled substance and either a substantially similar or greater central-nervous-system effect or the relevant person's representation or intent concerning such an effect, subject to statutory exclusions for controlled substances, approved drugs, qualifying investigational use, and substances not intended for human consumption as specified by the statute. A substance satisfying that definition is treated as Schedule I under § 813 only to the extent intended for human consumption; in that circumstance, §§ 841(a)(1) and 844(a) prohibit the specified knowing or intentional unauthorized manufacture, distribution, dispensing, possession with intent, and possession. Under McFadden v. United States, a § 841(a)(1) analogue prosecution also requires proof that the defendant knew the substance was controlled under the Controlled Substances Act or Analogue Act, or knew the specific features that made it an analogue; Methylnaphthidate is subject to analogue treatment only if these conditions are established in a particular case.

The Danish Medicines Agency's current comprehensive list (updated 31 March 2026) identifies the exact entry as Methylnaphthidat (HDMP-28), B325, with the chemical name Methyl-(naphthalen-2-yl)(piperidin-2-yl)acetat.