The Use of Amicus Curiae Briefs to Advance Plant Medicine Law

As cannabis and psychedelic plant medicines gain wider acceptance for medical and therapeutic use, legal battles over regulation and federal status are increasing. One important but often overlooked tool is the amicus curiae brief. It is Latin for “friend of the court.” These briefs let outside groups or experts, who are not direct parties, provide extra information, scientific evidence, and legal perspectives for the court to consider. In plant medicine law, amicus briefs are becoming a key strategy to guide legal interpretation and speed up reform.

What Is an Amicus Curiae Brief?

Amicus curiae literally means friend of the court. It is a legal document submitted to a court by someone who is not directly involved in a lawsuit but has a strong interest in the outcome. Amicus briefs provide insight, expertise, or context beyond what the actual parties might present. Their primary purpose is to help judges understand the broader implications of legal questions before them.

How Amicus Briefs Work?

In the U.S., anyone with relevant expertise or interest, such as advocacy groups, medical professionals, researchers, or industry organizations, can request to file an amicus brief. The court decides whether to accept it. These briefs can back one party’s argument or introduce new legal or factual points that may influence the court’s final decision.

Why Amicus Briefs Matter in Plant Medicine Law?

Plant medicine law covers cannabis, psychedelics, and related substances. It touches on complex science, public health considerations, and rapidly evolving policy. These factors make it an area where amici (friends of the court) can provide valuable insight and context.

1.   Bringing Scientific and Medical Evidence to the Court

Scientific evidence on medical efficacy and safety is central in many cannabis and psychedelic cases. Amicus briefs allow experts to present this research directly to judges. For instance, in psilocybin rescheduling litigation, researchers and clinicians have filed briefs summarizing studies showing therapeutic benefits for conditions such as anxiety and depression.

2.   Highlighting Public Policy and Human Impact

Beyond pure science, amicus briefs can describe policy implications and human consequences of decisions. Clinicians advocating for patients with terminal illness have filed briefs arguing that restricting access to psilocybin therapy deprives vulnerable people of relief at the end of life. These arguments give courts a fuller picture of the stakes beyond legal technicalities.

3.   Bridging Gaps in Legal Arguments

While the parties in a case may focus on narrow procedural issues, amicus briefs can provide a broader context. They may include historical background, federalism concerns, or wider interpretations of constitutional and statutory law. This perspective is especially important in cases with potential national implications for cannabis or psychedelic policy.

Key Examples in Plant Medicine Law

Amicus briefs have played a growing role in major plant-medicine cases. These filings have helped shape court decisions and influence the direction of cannabis and psychedelic law reform.

(I) Psilocybin Rescheduling Cases

One of the clearest modern examples is the legal debate over whether psilocybin should be rescheduled under the U.S. Controlled Substances Act (CSA). Right now, psilocybin is listed as a Schedule I substance. This classification means the federal government considers it to have no accepted medical use and a high risk of abuse, despite growing scientific evidence that challenges this view. 

To support efforts to change this status, nearly 30 clinicians and advocacy groups filed amicus briefs with the U.S. Court of Appeals for the Ninth Circuit. These briefs urged the court to require the Drug Enforcement Administration to begin formal rescheduling proceedings. They argued that current clinical evidence and public health needs no longer support keeping psilocybin in Schedule I.

Similarly, prominent researchers and organizations such as Johns Hopkins Medicine and international scientific experts have backed amicus briefs by arguing that compelling evidence supports moving psilocybin to a less restrictive schedule to promote research and therapeutic use. 

(II) Cannabis Scheduling and Regulation

While they receive less attention than psychedelic cases, amicus briefs have also shaped cannabis law. In cases challenging cannabis’s status under the Controlled Substances Act, advocacy groups such as NORML have filed amicus briefs that document the federal government’s long-standing resistance to recognizing medical cannabis. These filings highlight growing scientific evidence and widespread state-level reforms, helping courts see the gap between federal policy and modern medical and legal realities.

Past efforts in cannabis law also include challenges based on conflicts between federal scheduling and state legalization, where amici have sought to explain how federal interpretations can undermine state‑level regulatory systems.

(III) Hemp Regulation and the Farm Bill

In Hemp Industries Association vs DEA, members of the U.S. Congress filed an amicus brief supporting hemp industry groups that were challenging Drug Enforcement Administration rules. Those rules conflicted with the intent of the 2014 Farm Bill, which allowed legal hemp products such as CBD oil.

While the brief did not settle the broader question of hemp legality, it played an important role. It helped clarify congressional intent and highlighted the tension between federal legislation and agency regulation.

Challenges and Limitations

Although amicus briefs can be influential, they do not guarantee an impact on a court’s decision. Judges choose whether to accept them, and even accepted briefs may carry little weight if they do not speak directly to the legal questions before the court.

There is also a practical barrier. Preparing an amicus brief requires legal skill and often formal representation. This makes participation harder for small advocacy groups or grassroots movements. As a result, well-funded organizations and established institutions tend to dominate amicus filings.

Why Amicus Briefs Are Likely to Grow in Importance?

As plant medicine policy continues to change, courts will face harder and more complex questions. These include how federal scheduling should work, who can access medical research, how religious freedom applies, and how state laws interact with federal rules. As these issues grow, courts will play a bigger role in shaping how plant medicines are regulated and understood. 

In this environment:

• Scientific evidence will matter more and more, and amicus briefs can help present that evidence in a clear, useful way that judges can easily understand.

• Public and patient voices will seek platforms to influence judicial perspectives.

• Interdisciplinary perspectives will be essential. Legal, medical, and ethical viewpoints can help courts understand cases that affect many areas of public policy.

These trends show that amicus briefs will continue to be a useful tool for advocates. They are especially important when laws move more slowly than science or public opinion on plant medicine.

Conclusion

Amicus curiae briefs provide a critical link between the courts and broader public interests in plant medicine law. By bringing scientific evidence, policy analysis, and real‑world concerns to legal disputes over cannabis and psychedelics, amici help ensure that judicial decisions consider more than the narrow arguments of the parties involved. For advocates working on the frontier of plant medicine reform, understanding and using amicus briefs effectively is essential to shaping how laws adapt to new medicines and evolving public health priorities.