On October 27 Japan’s Ministry of Health, Labour and Welfare promulgated a ministerial ordinance adding three compounds to its list of designated substances: N-desethyl protonitazene, a benzimidazole opioid; 5-MeO-MET, a methoxy tryptamine; and 2-F-tropacaine, an ester of tropine related to cocaine. The ordinance, No. 150 of 2026, was published in the Official Gazette that day and takes effect on November 6.
The same day, at least five prefectures designated the same three compounds under their own ordinances, effective October 28: Tokyo, Osaka, Chiba, Aichi and Gunma. A sixth, Fukuoka, applied a separate category of its own, one that triggers when another local government regulates a substance. Its notice cites Tokyo’s and Osaka’s action, not evidence of its own.
So the local prohibition bites nine days before the national one.
That gap is the mechanism, and it is more interesting than the ban.
Two systems, two speeds
The national instrument is the Pharmaceuticals and Medical Devices Act, not the Narcotics and Psychotropics Control Act. Article 2, paragraph 15 defines a designated substance as one highly likely to have psychotoxicity, meaning excitation or depression of the central nervous system or a hallucinogenic effect, and which risks harm to health when used on the body. Both limbs are prospective. The statute asks for high probability of the first and risk of the second, not demonstrated harm from either. It also excludes anything already controlled as a stimulant, a narcotic or opium.
The route is a ministerial ordinance rather than a statutory amendment, and the minister designates after hearing the Pharmaceutical Affairs Council. MHLW says that where the Council’s designated-substances subcommittee has found a substance appropriate for control, the public comment procedure is omitted so designation can be made promptly, to prevent harm from use. The subcommittee met on October 26. The ordinance was promulgated the next day.
The penalties sit in two tiers. Article 83-9 carries five years’ imprisonment or a ¥5 million fine, or both, where manufacture, import, sale, supply, or storage or display for sale is carried out as a business. Article 84 carries three years or ¥3 million, or both, for every other violation, including possession and use. A company whose employee commits the aggravated offence faces a fine of up to ¥100 million.
The prefectural instrument is faster and narrower. Tokyo says 25 prefectures, itself included, maintain ordinances creating a category of governor-designated substance. Tokyo’s standard, under Article 12 of its 2005 ordinance, covers substances that act on the mind through stimulation, hallucination, intoxication or similar effects, whose abuse is recognised as harming health, and that are being abused in Tokyo or are at risk of being abused there. The Tokyo Drug Information Evaluation Committee analyses the hazard information and reports to the governor, though in an emergency the governor may designate without it. Designation takes effect by public notice; here, in every prefecture that acted, that was the following day.
What a prefecture cannot do is control imports. None of the ordinances examined reaches importation, and border measures attach to the national designation. Nor are the prefectural penalties uniform. Tokyo’s heaviest provision is two years’ imprisonment or ¥1 million, for defying a metropolitan order; manufacture, cultivation, sale and possession for sale carry one year or ¥500,000; advertising, possession, purchase, acquisition and use carry six months or ¥300,000. Chiba’s principal penalties are one year or ¥500,000 and six months or ¥300,000 across the same two tiers. Tokyo’s ordinance carves out research, testing and industrial use.
What the lapse data show
Aichi publishes the clearest record. Between October 16, 2012 and August 18, 2026 it designated 250 substances. All 250 have lapsed, because each was subsequently covered both by the national designated-substance provision and by the ministerial ordinance governing medical and similar uses. Aichi’s current count of governor-designated substances is three, and they are these three.
Gunma shows the same pattern at a different scale. It has designated 187 substances, all of which have lapsed, 31 of them having gone further and been designated as narcotics. Its current count is also three.
Tokyo’s own total has the same shape. It has designated 261 substances since 2005 and says every one has since become a minister-designated substance or a narcotic. Its live count is three.
The prefectural designation is not a parallel ban. It is a bridge, built to cover the interval between a compound being identified and the national ordinance taking effect, and it dissolves when the national list catches up. That the three prefectures publishing running totals are all now holding exactly three substances, the ones designated this week, is the pattern in its clearest form.
Tokyo publishes one further figure, and it needs care. Of the 261, it records 160 as substances whose domestic circulation was unconfirmed at the time of designation, a category it labels pre-emptive domestic regulation; in the current fiscal year the figure is six of ten so far. But Tokyo’s stated programme is aimed at unregulated substances whose circulation has been confirmed at home or abroad. The 160 therefore means Tokyo moved before the Japanese market was confirmed, not that the substances had been seen nowhere. Tokyo publishes no definition of what confirmation requires.
Why these three, as far as the record shows
One of the three has a documented presence inside Japan. Chiba’s notice records, under a heading on circulation status, that domestic circulation has been confirmed for 2-F-tropacaine. No prefectural notice asserts domestic circulation of the other two, and none asserts its absence either.
The other two are not equally obscure, and the difference is worth having. 5-MeO-MET was notified to the European Union’s early warning system by Sweden on June 21, 2012, and has been on Norway’s narcotics list since 2013. Its pharmacology has been measured: a 2024 paper in Molecular Psychiatry characterised it as one of ten methoxytryptamines, reporting receptor binding, transporter effects and mouse behavioural data. The compound is named nowhere in that paper’s title or abstract, which is why searching a bibliographic database for it returns nothing.
2-F-tropacaine is the one with almost no record at all. It returns nothing in PubMed, nothing in the Federal Register, nothing in the published monograph series of the Center for Forensic Science Research and Education, and nothing in J-STAGE, which indexes most Japanese journals, searched in English and in Japanese. Whether either compound has reached the European or United Nations early warning systems since 2015 cannot be established from outside them. Substance-level records in both are restricted to national authorities, and the European agency stopped publishing per-substance annexes that year.
The opioid is the exception. DEA placed N-desethyl protonitazene in Schedule I on October 15, 2025, by a temporary order covering seven benzimidazole opioids and running to October 15, 2027. DEA recorded nine law-enforcement encounters across six states, said the substances are often mixed with other illicit drugs and commonly co-detected with designer benzodiazepines, and wrote that “the benzimidazole-opioids have a similar pharmacological profile to fentanyl, morphine, and other mu-opioid receptor agonists.” The compound is both a designer opioid seized in its own right and a confirmed metabolite of protonitazene, identified as a metabolite in eleven cases and as a parent compound in seven. The class has a body count where anyone has looked for it: the Office for National Statistics registered 195 deaths involving nitazenes in England and Wales in 2024, against 52 the year before. None of that attaches to this compound in particular, and every such figure is a floor, because nitazenes sit outside routine toxicology panels and degrade in stored blood.
Japan’s notices describe it differently. Chiba’s says the compound is considered highly likely to have excitatory action accompanied by euphoria. Tokyo groups all three under stimulation, hallucination and intoxication. No prefecture calls it an opioid, and the words opioid, fentanyl and nitazene appear in none of the six notices. The two records are doing different jobs. DEA was characterising an established pharmacological class after seizures and toxicology; the Japanese notices are prospective findings made under a probability standard, before that evidence would be required. Nothing in the public record reconciles them, and neither side explains the other.
MHLW’s release gives no compound-specific trigger, no seizure count and no case report. It says the three also circulate overseas and that it will strengthen border measures and enforcement against internet sales of unapproved drugs. Neither Tokyo nor Chiba supplies more.
One boundary is worth stating plainly, because the naming invites confusion. 5-MeO-MET is 5-methoxy-N-methyl-N-ethyltryptamine. It is not 5-MeO-DMT, which differs by a single carbon and carries the international nonproprietary name mebufotenin. This action does not touch mebufotenin or any clinical program using it.
What the mix says
An opioid, a tryptamine and a tropane, listed in one batch, share no drug class, no common source and no reported harm. What they share is the statutory test. Each was found highly likely to act on the central nervous system and to risk harm if used, and under this Act that is the whole of what designation requires.
The prefectural layer is built to be temporary, and three prefectures have now published what that looks like across more than a decade. Aichi designated 250 substances and has none of them left. Gunma designated 187 and has none left. Tokyo designated 261 and has none left. Each is holding exactly three today, and on November 6 those three go the same way.