Japan’s Historic Cannabis Law Reform: Criminalizing Use While Opening the Door to Medicine

How can Japan criminalize cannabis use and legalize medical access at the same time?

How can a country criminalize the use of cannabis and legalize medical access at the same time? That is precisely what Japan did on December 12, 2024, when the amended Cannabis Control Act (CCA) took effect — a contradiction that has left regulators, investors, and patient advocates scrambling to understand what it means in practice. Japan cannabis law 2024 is arguably the most paradoxical reform in the global cannabis story: tighter criminal penalties for recreational consumers combined with a newly opened door for pharmaceutical-grade cannabis products. For operators and investors eyeing Asia’s rapidly expanding cannabis market, understanding this dual-track approach is now non-negotiable.

Japan Cannabis Law 2024: What the Amended Cannabis Control Act Changes

Japan’s relationship with cannabis has always been complicated by history. Hemp cultivation (taima) has deep roots in Shinto ritual and traditional farming, yet post-WWII occupation-era legislation — shaped heavily by U.S. drug policy — imposed some of the world’s strictest cannabis prohibitions. For decades, the Cannabis Control Act banned cultivation, possession, and transfer of cannabis but contained a notable gap: it did not explicitly criminalize use. That gap closed on December 12, 2024.

The 2024 amendment to the Cannabis Control Act represents a dual-tracked overhaul:

Track 1 — Tighter Criminal Restrictions: The revised law explicitly adds cannabis use as a criminal offence, closing the loophole that allowed law enforcement to pursue users only indirectly through possession charges. Maximum penalties across the board — for possession, transfer, and now use — were raised from 5 years to 7 years imprisonment.

Track 2 — Medical Regulatory Pathway: The amendment removes the blanket prohibition on cannabis-derived pharmaceuticals that had long blocked clinical drug development. Cannabis-derived medicines are now brought under the same regulatory framework as opioid analgesics, allowing sponsors to submit marketing approval applications to the MHLW. This is the first time Japan has created a formal route for physicians to legally prescribe cannabis-derived products.

The backdrop to this reform is Japan’s worsening youth cannabis problem. The Ministry of Health, Labour and Welfare (MHLW) reported approximately 6,000 cannabis-related arrests per year, with the sharpest increases among individuals under 30. The government concluded that the absence of a use-specific penalty undermined deterrence — particularly among young people who understood the legal distinction between “use” and “possession.”

The reform also modifies rules around industrial hemp. The longstanding restriction that limited industrial use to mature stalks and seeds has been lifted, but this has been offset by the introduction of strict THC concentration thresholds to ensure hemp remains clearly distinguished from drug-type cannabis.

Criminalizing Use — The New Penalties and Why It’s Paradoxical

Prior to December 2024, Japan was unusual among developed nations in that it could prosecute cannabis consumers only if police could prove possession — the act of using cannabis was not itself illegal under the Cannabis Control Act. Prosecutors worked around this through creative charging, but the legal gap was real and widely known.

The 2024 amendment closes this gap decisively. Under the new law:

• Cannabis use carries a penalty of up to 7 years imprisonment.
• Possession and transfer penalties were also raised from 5 years to 7 years maximum.
• Commercial offences (cultivation for profit, international trafficking) carry enhanced penalties.

The paradox emerges when you place these penalties alongside the medical provisions in the same legislation. Under the amended act, a licensed physician in Japan can now prescribe a cannabis-derived pharmaceutical to a patient — yet a recreational consumer who uses the identical compound without a prescription faces up to 7 years in prison. The law creates an explicit legal category for “permitted medical cannabis” while simultaneously casting the broadest possible criminal net over all non-medical use.

This mirrors the policy logic of several other conservative Asian jurisdictions — notably South Korea, which opened a narrow medical cannabis window in 2019 while maintaining severe penalties for recreational use — but Japan’s version is particularly stark given how recently the use-specific prohibition was absent altogether.

Critics argue the approach is contradictory and unlikely to reduce youth cannabis use given the explosive growth of unregulated online markets. Supporters contend it is pragmatic: creating pharmaceutical infrastructure without signalling any tolerance for recreational use. The government’s position, as articulated by MHLW officials, is that the two tracks are complementary — criminalizing misuse actually provides the political cover necessary to permit medical development.

Medical Cannabis in Japan: What Patients Can Now Access

Before the 2024 reform, cannabis-derived pharmaceuticals — including cannabidiol (CBD) drugs that had received regulatory approval in the United States and Europe — could not be legally prescribed or imported for medical use in Japan. Epidiolex (GW Pharmaceuticals’ CBD drug for childhood epilepsy) was one prominent example: approved by the FDA in 2018 and by the EMA in 2019, it remained completely unavailable to Japanese patients because the Cannabis Control Act categorically banned all cannabis-derived products regardless of medical merit.

The 2024 amendment changes this framework structurally:

Regulatory Pathway: Cannabis-derived medicinal products are now classified under the same framework as controlled medicines including opioid analgesics. Pharmaceutical companies can submit New Drug Applications (NDAs) to the MHLW for cannabis-derived drugs, and physicians with appropriate licensing can prescribe them.

Conditions Likely to Benefit: Regulatory observers expect initial applications to focus on treatment-resistant epilepsy (particularly in paediatric patients), nausea and vomiting associated with chemotherapy, chronic pain management, and multiple sclerosis-related spasticity.

Clinical Trials: Japan has permitted limited cannabis-related clinical research since 2022, when a Phase 3 trial of a CBD-based paediatric epilepsy medication commenced. The 2024 reform accelerates this pathway significantly.

Import and Domestic Manufacture: Licensed entities can now import cannabis-derived pharmaceutical ingredients and, subject to MHLW approval, establish domestic manufacturing. This opens a supply chain conversation for international cannabis-pharmaceutical companies exploring Japan market entry.

The MHLW has indicated it will take a conservative, case-by-case approach to approvals. Japan’s pharmaceutical regulatory process is deliberate and thorough — observers do not expect rapid approvals. But the existence of a legal pathway where none existed before represents a fundamental structural shift that will define Japan’s pharmaceutical cannabis landscape for the next decade.

The CBD Market: Japan’s Grey Area Gets More Complex

Japan’s CBD market had already been growing rapidly before the 2024 reform, driven by consumer interest in wellness products and a regulatory environment that technically permitted CBD derived from hemp stalks and seeds. By 2024, the Japanese CBD retail market had reached substantial scale, with products including oils, capsules, and topicals widely available in pharmacies and online.

The 2024 amendment introduces new complexity for this market. The revised law imposes explicit THC concentration thresholds on hemp and hemp-derived products — effectively tightening scrutiny of existing CBD supply chains. Products that previously existed in a comfortable grey zone now face more clearly defined compliance requirements.

Key CBD market realities post-reform:

• Still Permitted: CBD products extracted from hemp stalks or seeds, verified to be free of detectable THC, remain legal for general retail sale.
• Under Stricter Scrutiny: The new THC thresholds require supply chain verification at a level many existing importers have not previously maintained.
• Leaf and Flower Extracts: CBD extracts from hemp leaves or flowers remain prohibited under the Cannabis Control Act, regardless of THC content.
• Pharmaceutical-Grade CBD: For the first time, CBD-based medicines (as distinct from wellness products) have a formal regulatory pathway through the MHLW drug approval process.

The net effect is a market that is simultaneously expanding at the pharmaceutical end and becoming more rigorously regulated at the retail end. For existing CBD market participants, the 2024 reform signals that the era of regulatory ambiguity is ending — compliance infrastructure is now an operational necessity, not an optional investment.

What Operators and Investors Need to Know

Japan represents one of the most significant emerging opportunities in the Asia-Pacific cannabis sector — but it is also one of the most challenging markets to enter. The 2024 reform does not liberalize Japan’s market in any conventional sense; it creates a narrow, highly regulated pharmaceutical channel while hardening restrictions everywhere else.

Asia-Pacific Market Context: The Asia-Pacific medical cannabis market was valued at USD 4.69 billion in 2024 and is projected to reach USD 35.28 billion by 2033, growing at a CAGR of 25.13%. Japan alone is projected to grow at 35.5% CAGR — one of the fastest growth trajectories in any regulated cannabis market globally.

For Pharmaceutical Companies: The primary near-term opportunity is the MHLW regulatory pathway for cannabis-derived drugs. Companies with existing clinical data packages — particularly those with approved CBD products in North America or Europe — are best positioned to initiate Japanese NDA filings. Local regulatory expertise and a Japanese co-development or commercialisation partner are widely recommended.

For CBD Product Companies: The post-2024 environment demands documented supply chain compliance: verified THC-free testing, appropriate extraction methodologies, and product category clarity (pharmaceutical vs. wellness). Companies that built their Japan operations on ambiguous regulatory tolerances should conduct immediate compliance reviews.

For Cannabis Technology and Compliance Platforms: As Japan’s regulated cannabis sector develops, demand for cannabis compliance software adapted to MHLW requirements will grow. Track-and-trace systems, quality management documentation, and regulatory reporting infrastructure are standard requirements in every market that has opened a pharmaceutical cannabis pathway.

Operational Cautions:

• Japan has zero tolerance for recreational cannabis. Foreign nationals — including employees at licensed pharmaceutical entities — face the same criminal penalties as Japanese citizens.
• The regulatory timeline for MHLW pharmaceutical approvals is measured in years, not months.
• Local partnership with established Japanese pharmaceutical or healthcare companies is the most practical market entry strategy.
• Watch for MHLW guidance documents clarifying THC thresholds and CBD product classification — these will shape compliance requirements for years ahead.

Japan’s dual-track reform is a signal, not a green light. The signal is clear: cannabis-derived pharmaceuticals are coming to Japan, and the regulatory infrastructure to receive them is being built. For operators who approach the market with the right compliance foundation, the long-term potential is substantial.

Frequently Asked Questions

What does Japan cannabis law 2024 mean for the medical sector?

The 2024 amendment to Japan’s Cannabis Control Act creates the country’s first formal regulatory pathway for cannabis-derived pharmaceutical products. Licensed pharmaceutical companies can now submit New Drug Applications to the MHLW, and licensed physicians can prescribe approved cannabis-derived medicines. The focus is expected to be on conditions like treatment-resistant epilepsy, chemotherapy-related nausea, and chronic pain. Approvals will follow Japan’s rigorous pharmaceutical review process, making significant market penetration a multi-year process. Sources: Japan Times, DIA Global Forum.

Is CBD legal in Japan?

CBD is in a legal grey area in Japan. Products containing CBD derived from hemp stalks or seeds that are verified to contain no detectable THC are permitted for retail sale. CBD extracted from hemp leaves or flowers remains prohibited. The 2024 Cannabis Control Act amendment introduced explicit THC concentration thresholds that tighten compliance requirements for existing CBD products. The new law also creates a separate pharmaceutical pathway for CBD-based medicines, distinct from retail wellness products. Source: Mori & Partners.

Can foreign companies operate in Japan’s cannabis market?

Foreign companies can pursue Japan market entry, but the environment requires careful navigation. On the pharmaceutical side, companies with clinical data packages for cannabis-derived drugs can initiate MHLW regulatory filings, though local regulatory expertise and typically a Japanese co-development or commercialisation partner are essential. On the CBD retail side, foreign companies supplying products to Japan must ensure full supply chain compliance with THC-free verification requirements. Direct recreational cannabis operations are not possible — Japan’s zero-tolerance stance applies equally to foreign nationals. Source: Japan Today.

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