Why medicinal plants matter more than ever in a changing climate

Medicinal plants have shaped healthcare throughout history and continue to underpin modern medicine today. Examples of some of the most important drugs originate from plants, including:

• Pacific yew (Taxus brevifolia), the source of the anticancer drug taxol
• Sweet Annie (Artemisia annua), which yielded artemisinin for malaria treatment
• Opium poppy (Papaver somniferum), the origin of morphine
• Autumn crocus (Colchicum autumnale), used to treat gout and inflammatory conditions

Beyond these well-known examples, many other medicinal plant species remain underexplored, representing valuable potential for future therapeutic discoveries.

Medicinal plants also play a vital ecological and social role. They support biodiversity, pollinators, and soil health (1-3), and form the backbone of traditional healthcare systems and local economies—particularly in rural and Indigenous communities (4). Knowledge passed down through generations has guided the use of plants, such as snowdrop species (Galanthus spp.), inspiring neurological treatments, and Chinese angelica (Angelica sinensis), which remains central to traditional Chinese medicine (5,6). Protecting medicinal plants, therefore, means protecting health, culture, and livelihoods — now and for generations to come.

Despite their importance, medicinal plants are increasingly at risk. Specifically, our analysis reveals clear and consistent patterns in how medicinal plants are responding to climate change. Drawing on a scoping review of 367 medicinal plant species, we found that the most common predicted impact is the loss of suitable habitat, affecting 131 species, largely driven by changes in precipitation patterns and elevation.

Range shifts were observed in 97 species, with many plants moving toward higher altitudes and latitudes. In comparison, 73 species showed an increase in suitable habitat—suggesting that climate change may create new opportunities for a limited number of plants (Figure 1) (7).

These distributional changes have direct implications for the pharmaceutical and cosmetic industries, with knock-on effects throughout herbal value chains. Many of the most studied medicinal plants — whether cultivated or wild-harvested — are susceptible to climate-driven changes in temperature and rainfall. This includes species such as jatamansi (Nardostachys jatamansi), chonglou (Paris polyphylla), chuan bei mu (Fritillaria cirrhosa), and ma huang (Ephedra sinica). As a result, regions once considered reliable sources may become less productive or unsuitable, leading to reduced yields, supply disruptions, and increased uncertainty in sourcing raw plant materials. At the same time, the loss of vulnerable species limits opportunities to discover new therapeutic agents, narrowing the future potential of plant-based innovation.

Climate-driven shifts also pose significant challenges for geographical indications (GIs), including traditional concepts such as Daodi and European notions of provenance and terroir, which link product quality to specific ecological and cultural conditions. As climates change, the environmental foundations that give these regions their distinctive phytochemical profiles may no longer hold. Established GI zones may therefore need to adapt, relocate, or be redefined — raising important questions about quality standards, authenticity, and regulation (8).

Global warming may significantly alter the production of bioactive metabolites and marker compounds in medicinal and aromatic plants by increasing potential evapotranspiration due to elevated temperatures, which in turn accelerates soil drying (9). The resulting changes in phytochemical profiles are highly variable and depend on the plant species, the specific type of compounds, as well as the intensity and duration of drought stress (10).

Moderate drought often enhances the accumulation of various secondary metabolites, especially those with antioxidant properties. This is attributed to the induction of mild oxidative stress, which triggers the biosynthesis of protective compounds such as phenolics and flavonoids to scavenge reactive oxygen species (ROS) (11). When drought becomes prolonged and severe, plant metabolic processes are significantly disrupted (12). This contrasting pattern was evident in several species reviewed. For example, under water deficit conditions, both balangu (Lallemantia royleana) and Persian lilac (Melia azedarach) exhibited increased phenolic and flavonoid content (13,14).

However, in broadleaved lavender (Lavandula latifolia), drought conditions resulted in decreased levels of specific metabolites such as coumaric and salvianic acids (15).

As a major contributor to climate change, elevated CO₂ and temperature exhibit mixed results; in certain cases, they can enhance the production of some compounds while suppressing others, due to complex carbon allocation and temperature sensitivities (81). High temperatures alone reduce the levels of several secondary metabolites, likely due to metabolic shifts that favour survival over defence (16).

Changes in precipitation also influence metabolite levels, with reduced rainfall often linked to a decline in compound diversity, particularly in drought-sensitive species (17). In addition, temperature stress elevates volatile organic compounds, suggesting an upregulation of stress signaling or defense responses (18). 

These fluctuations in secondary bioactive metabolite and marker compound profiles could impact the potential risks and benefits of medicinal plants. Increased levels of certain compounds could enhance antioxidant, anti-inflammatory, or antimicrobial activity, while a decline in key bioactive may compromise the potential effectiveness of traditional and plant-derived preparations (19,20).

Similarly, the pharmaceutical and cosmetic industries face significant challenges. Drought, for instance, alters the synthesis of essential oils, phenolic compounds, and flavonoids, key compounds in skincare, personal, and healthcare products. Changes in the levels of bioactive metabolites or marker compounds, such as linalool, linalyl acetate, α-pinene, and borneol in lavender (21) or camphor and linalool in basil (Ocimum basilicum), as well as various compounds in rosemary (Salvia rosmarinus), due to drought, and/or heat stress, could explain these biochemical shifts (22,23).

These phytochemical shifts (including changes in the levels of bioactive metabolites or marker compounds) can affect the quality (including the safety and efficacy of plant-derived medical products) and sensory properties of cosmetic and healthcare products (21).

Overall, climate-driven changes in bioactive metabolites raise important questions about quality, safety, and consistency. While some plants may benefit from moderate stress, others may lose critical properties. At present, simple predictions are not possible, highlighting the need for longer-term and comparative research.

Climate change is increasingly undermining both biodiversity and the traditional healthcare systems that depend on medicinal plants. For instance, in the Central Himalayas, rising temperatures and shifting rainfall have advanced flowering and fruiting times by several weeks, disrupting culturally rooted harvesting practices and reducing the availability and effectiveness of key medicinal species. Traditional healers report growing reliance on substitute plants, which are often significantly less effective (24).

Similar patterns are emerging in northern Thailand, where medicinal plants used by Karen communities — particularly in women’s reproductive healthcare — are projected to lose much of their suitable habitat in the coming decades (25). Comparable challenges are faced by the Shan people and forest-dependent communities near the Chunati Wildlife Sanctuary, where limited access to formal healthcare increases reliance on traditional medicine (26).

As climate change alters the distribution, timing, and potency of medicinal plants, the resilience of these community-based healthcare systems is coming under increasing strain.

Safeguarding medicinal plants in a changing climate requires coordinated action across policy, conservation, industry, and communities: 

• Climate-resilient cultivation and agroforestry: Diversified cultivation systems and agroforestry can reduce pressure on wild populations while strengthening ecosystem resilience, but wider adoption will require investment and integration into land-use planning.
• Genetic conservation and species management: Seed banks, tissue culture, and germplasm conservation offer critical insurance against loss, but must be paired with fair benefit-sharing and livelihood support.
• Community-led and participatory conservation: Recognising Traditional Ecological Knowledge and supporting local stewardship has proven more effective than top-down approaches.
• Stronger policy frameworks and incentives: Clear regulation and economic incentives — such as Payments for Ecosystem Services — can reduce illegal harvesting while supporting sustainable trade.
• Research, training, and capacity building: Knowledge gaps remain across many medicinal-plant-producing regions. Long-term monitoring, targeted funding, and specialist training are essential to translate research into meaningful action.

Medicinal plants are a shared global resource, but their future depends on the choices we make today. Climate change has transformed sustainability from an environmental concern into a health, cultural, and economic imperative. By supporting responsible sourcing, sustainable cultivation, and informed policy, we can help ensure that medicinal plants continue to support the well-being and health of people and planet.  

Protecting medicinal plants today safeguards healing possibilities that cannot be recovered once lost.”

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