The Re-emergence of Botanical Medicine

Somewhere between 50 and 70 CE, a Greek physician named Pedanius Dioscorides compiled De Materia Medica , a five-volume catalogue of roughly 600 plants and their observed uses. It stayed in active clinical circulation for over 1,500 years. Let that sink in. No pharmaceutical patent has ever come close.

I keep that fact in mind whenever I hear the phrase "plant-based medicine is making a comeback." It never really went away. What changed was the language we used to describe it, the institutions that controlled it, and , honestly , the money behind it.

How botanical knowledge was systematised (and then sidelined)

For most of recorded history, medicine and botany were the same discipline. Herbalists, apothecaries, indigenous healers across every continent; they were all, at root, doing the same thing: observing how plant-derived compounds interacted with the human body over time. The results were written into pharmacopoeias, passed down through apprenticeship, encoded in country-specific healing traditions.

The divergence came fast. The late 19th and early 20th centuries brought the isolation of active compounds, morphine from opium poppy in 1804, quinine from cinchona bark, salicin from willow that eventually became aspirin. Once chemists could extract, purify, and eventually synthesise a single molecule, the whole-plant preparation started to look crude by comparison. Imprecise. Unprofessional.

The pharmaceutical industry that emerged from this period was built on a reductionist premise: find the one active molecule, patent it, scale it. Whole plants, with their hundreds of co-occurring compounds, didn't fit that model cleanly. You can't patent a plant.

By mid-20th century, the regulatory architecture that now governs medicines had largely crystallised around the single-entity drug. In Australia, the Therapeutic Goods Administration's Australian Register of Therapeutic Goods (the ARTG) reflects this: a listed or registered medicine needs a defined, characterised product. That's not impossible for botanical medicines, but it takes real effort, which brings us to standardised extracts, the contemporary attempt to give plant medicines the kind of batch-to-batch consistency that regulators and researchers need.

The "crude" plant problem; and why it's more complicated than it sounds

The standard critique of botanical medicine in the 20th century was essentially: "You don't know what's in it." And to be fair, that criticism had real teeth. A dried herb purchased in one decade from one supplier was often chemically quite different from the same herb from a different source or season. Research conducted on that basis was nearly impossible to replicate, which made it nearly impossible to build an evidence base.

But the inverse assumption, that a purified single compound is always superior, has its own problems. This is something I'd argue the industry underestimated for decades. Many plant compounds work differently in isolation than they do in combination. Cannabis research has explored this extensively under the concept of the entourage effect, the hypothesis that cannabinoids, terpenes, and other constituents interact in ways that alter the pharmacological profile of the whole preparation compared to any single extracted component. The science here is still genuinely unsettled; I want to be clear about that, but the question itself is legitimate and not fringe.

Similar complexity appears in studies of other botanical preparations. The active fraction of a plant extract and the "inert" fraction are often harder to separate than the original model assumed.

Cannabis: a case study in regulatory history

Few plants illustrate the 20th-century arc of botanical medicine as starkly as Cannabis sativa. Used medicinally across Asia, the Middle East, and Europe for centuries, it was listed in the United States Pharmacopoeia until 1942. In Australia, it was progressively restricted across state and federal legislation, eventually classified as a prohibited substance.

The chemistry that drove renewed scientific interest came later. Raphael Mechoulam's laboratory in Israel isolated tetrahydrocannabinol (THC) in 1964. The subsequent discovery of the endocannabinoid system in the late 1980s and early 1990s, including the identification of CB1 and CB2 receptors, and endogenous ligands like anandamide; reframed the question entirely. Cannabis wasn't just a plant with psychoactive properties. It was interacting with a receptor system that humans (and most vertebrates) already have.

In Australia, the regulatory response took decades. Medicinal cannabis was legalised at the federal level in 2016 through amendments to the Narcotic Drugs Act 1967, and access pathways including the Special Access Scheme and Authorised Prescriber framework were progressively developed by the TGA. Prescriptions involving THC-containing products are subject to Schedule 8 (Controlled Drug) requirements under the Poisons Standard; CBD products below certain concentrations were down-scheduled to Schedule 4 (Prescription Only) in 2020, with a low-dose OTC pathway opened in 2021. The regulatory picture is still evolving.

Ethnobotany, traditional knowledge, and the evidence question

One thing that gets lost in the pharmaceutical-versus-botanical framing is how much of our current drug discovery pipeline traces directly back to traditional plant knowledge. Ethnobotany, the study of how cultures have historically used plants, has functioned as an informal research database for formal pharmacology for over a century. Quinine, artemisinin (the antimalarial compound derived from Artemisia annua, a plant used in Chinese medicine for roughly 2,000 years), tubocurarine from South American curare; the list is long.

This creates an uncomfortable tension. The traditional knowledge that pointed researchers toward a plant rarely gets acknowledged in the patent that follows. That's an ongoing and legitimate ethical argument in international law, including under the Convention on Biological Diversity's Nagoya Protocol, which Australia ratified in 2022. I'm not going to pretend that tension doesn't exist, because it does.

On the evidence question specifically: traditional use is not clinical evidence of efficacy, but it is a reasonable signal for directing research attention. The two things are not the same, and conflating them, in either direction, is a mistake. Traditional use doesn't validate a therapeutic claim. But dismissing traditional use as superstition has also caused researchers to overlook genuinely interesting biochemistry for years at a time.

The modern re-emergence: what's actually driving it

A few threads converged in the early 21st century to push botanical medicine back into mainstream discourse. One was a genuine growth in mechanistic research; the identification of specific molecular targets (receptor systems, enzyme pathways) gave researchers better tools for understanding why a plant compound might have an observable biological effect. Another was growing public scepticism, fair or not, toward some corners of pharmaceutical medicine, particularly around long-term prescribing of certain drug classes. And a third, I'd argue, was the internet making traditional knowledge more widely available at exactly the moment that people were looking for it.

The result is a genuine mix. Some re-emerging botanical interest is backed by increasingly serious research infrastructure. Some of it is frankly marketing dressed in scientific-sounding language. Knowing how to tell the difference, checking whether a claimed mechanism has peer-reviewed support, whether a product meets Good Manufacturing Practice standards, whether the extract is characterised and standardised; matters more than ever.

I spent a Saturday last winter at Salamanca Market in Hobart watching a vendor spruik a herbal product with a diagram of receptors on the packaging. The diagram was real chemistry. Whether the product in the bottle did anything to those receptors was a separate question entirely, and one the packaging didn't answer. That gap, between plausible mechanism and demonstrated effect in a characterised preparation, is where a lot of the hard yards in botanical medicine still need to be done.

Where the research sits now

The honest answer is: unevenly. Some plant-derived compounds have strong evidence bases behind them and have completed the process of becoming approved medicines. Others have preliminary in-vitro or animal data that is genuinely interesting but hasn't yet translated to well-designed human trials. A third category has almost nothing behind it except historical use and enthusiastic marketing.

The re-emergence of botanical medicine as a serious research field is real. The funding is increasing, the methodological tools are improving, and the molecular targets are better understood than they were even fifteen years ago. But "re-emerging" doesn't mean "arrived." The work is ongoing, and the evidence base; like the plants themselves, takes time to grow.

Sources

• Medicinal Cannabis Guidance Documents, Therapeutic Goods Administration (TGA)
• The Endocannabinoid System as an Emerging Target of Pharmacotherapy; NCBI / Pharmacological Reviews
• WHO Traditional Medicine Strategy 2014–2023, World Health Organization
• Ethnobotany and the Role of Plant Natural Products in Antibiotic Drug Discovery, NCBI / Chemical Biology & Drug Design

, Hannah Bui, Evidence & research-literacy writer