Did Neanderthals Use Medicinal Plants?

Around 50,000 years ago, a Neanderthal living in what is now northern Spain accumulated plaque that later hardened on the teeth. When researchers analysed that deposit, they found chemical traces associated with yarrow and chamomile, plants with long histories of medicinal use. The hardened plaque recorded contact with plants that seldom survive as archaeological remains. What the evidence cannot immediately explain is whether the person had selected those plants to relieve an ailment.

A later DNA study detected poplar material in calculus from an El Sidrón Neanderthal with a dental abscess. Poplar contains chemicals related to compounds used in pain relief. Yet contact with a potentially useful plant does not by itself establish a remedy, its preparation or its effect. Food, flavouring, accidental exposure and deliberate treatment can all leave material in the mouth.

Microscopy, chemical analysis, ancient DNA and the study of injured bones now allow archaeologists to investigate these possibilities in greater detail. They have revealed plant use and complex behaviour that sit poorly with the old idea of Neanderthals eating almost nothing but meat. Each method also has limits: a mineralised tooth deposit can record exposure while keeping the individual’s reasons for that exposure beyond recovery. Claims about treatment therefore depend on distinguishing recovered traces from inferences about the actions that produced them.

What the teeth at El Sidrón revealed

Several Neanderthals were recovered from El Sidrón, a cave system in Asturias in northern Spain. They lived in the Middle Palaeolithic, tens of thousands of years before farming, writing or any surviving medical texts. Their communities hunted, gathered and made implements from stone and other materials, acquiring practical familiarity with their environment. Prepared plant material, wooden equipment and other organic objects mostly disappear after burial, leaving only scattered evidence of such activities.

Karen Hardy and colleagues investigated dental calculus from five El Sidrón individuals in research published in 2012. Calculus is plaque, a mixture of oral microorganisms and food debris, that has mineralised and can retain small particles and chemical substances. The team examined microscopic plant material and used thermal desorption and pyrolysis gas chromatography-mass spectrometry. These techniques heat samples, separate released chemicals and identify their molecular fragments. The published study in Naturwissenschaften identified plant-food residues, evidence associated with smoke and bitumen exposure, and compounds interpreted as possible signs of medicinal plant use.

Much attention centred on yarrow (Achillea millefolium) and chamomile (Matricaria). In one young adult’s calculus, the team identified substances related to azulene and coumarin, which they associated with these plants. Their bitter taste and history in herbal preparations led the researchers to suggest that the person might have selected them for treatment. If correctly identified, such traces can reveal plant contact where no preserved leaf or recognisable tool survives.

A residue can establish contact more readily than intention. Researchers first have to establish which chemicals survived and which plants could have produced them. Similar compounds can occur in several species, while burial and chemical alteration complicate identification. Even a secure plant identification would not reveal why it was chewed or eaten. Hardy and her colleagues proposed a medicinal explanation, but the directly observed evidence consisted of substances trapped in calculus.

The 2012 investigation also recovered starch granules and other plant material, including starch altered in ways compatible with processing or heating. That finding strengthened the case for consumption of plant foods. Amanda Henry, Alison Brooks and Dolores Piperno had reported comparable evidence in a 2011 study of dental calculus from Shanidar in Iraq and Spy in Belgium. They documented starch grains and phytoliths, the silica particles formed in plant tissues, with indications of grasses, legumes and other edible plants. Some grains appeared changed by cooking. These small deposits suggest food preparation and plant consumption without supplying a complete account of diet.

Why hardened plaque is useful, and what it cannot prove

Dental calculus is valuable because it can keep starch, phytoliths and microbial DNA after surrounding plant tissues have decayed. DNA may belong to organisms living in the mouth or introduced through food and the environment, while chemistry can detect substances even where no identifiable plant fragment survives. Those forms of evidence complement one another. None yields a complete, unbiased account of everything a person ate or handled during life.

Calculus can acquire contaminants during burial, excavation, storage or laboratory handling, even after the plaque has mineralised. Very small traces of chemicals or DNA are especially difficult to attribute confidently. Ancient-DNA researchers examine extraction controls, environmental comparisons and molecular damage consistent with age; chemical laboratories use blanks and reference samples. Unexpected findings from tiny samples require these checks before they can support strong claims.

A few plant particles cannot indicate the proportion of plants in someone’s diet. Meat may leave few recognisable inclusions even when eaten regularly. Hardy’s 2018 review of Pleistocene dental calculus warned that microscopic remains cannot straightforwardly be converted into food quantities; altered starch also needs cautious interpretation before being called proof of cooking. Calculus has to be read alongside butchered animal bones, dental wear, isotopic studies and environmental archaeology.

The term medicine does not identify why a plant entered the mouth. People might put plants in their mouths while eating, chewing, flavouring a meal, manipulating fibres with their teeth or trying to relieve a symptom. Any one of those actions could leave a similar residue. Neanderthals’ familiarity with plants is better established than the motivation behind a particular individual’s exposure, even when deliberate remedy use remains a reasonable possibility.

Were yarrow and chamomile taken for pain or illness?

People have used yarrow traditionally on wounds and for digestive trouble, and chamomile preparations have long been associated with inflammation and stomach discomfort. Laboratory and pharmacological research has investigated their constituents. Effects depend, however, on which species and plant part was used, how it was prepared and in what quantity. Modern experiments cannot tell us the dose an individual at El Sidrón received, or whether it was sufficient to help. No infusion, poultice or other preparation has survived from that cave.

The original interpretation placed weight on the plants’ bitterness. In 2009, Carles Lalueza-Fox and colleagues investigated variants of the bitter-taste receptor gene TAS2R38 in an El Sidrón Neanderthal. The genetic combination suggested that this individual could probably detect bitterness in the test substance phenylthiocarbamide. Their genetic study in Biology Letters established variation in this taste pathway among Neanderthals. It does not show that all of them perceived yarrow and chamomile identically, or that this receptor determines the taste of every bitter plant chemical.

People exposed to local plants over many years might observe whether certain roots, bark or leaves affected pain, appetite or digestion without understanding infection or inflammation as modern medicine does. Demonstrating that this informed a particular prehistoric choice is much harder. Hardy, Stephen Buckley and Michael Huffman, in their 2013 discussion of Neanderthal self-medication, proposed bitter, non-nutritive plants as possible remedies and compared the idea with self-medication documented in other animals. The comparison makes the behaviour plausible without identifying an individual act.

The calculus traces have several possible explanations beyond direct plant gathering. Laura Buck and Chris Stringer suggested that material could have arrived in the stomach contents of herbivores eaten by Neanderthals, citing ethnographic examples of people consuming partly digested food from prey. This has not been demonstrated for the person at El Sidrón. Their paper in Quaternary Science Reviews showed why plant remains in teeth need not mean the plants were collected directly. Sabrina Krief and colleagues considered flavouring and other possibilities while leaving treatment open. Advocates of the medicinal interpretation replied in a 2016 Antiquity debate.

The decisive details have not survived: the action that placed the plant in the mouth, the person’s condition at the time and any response to the substance. Bitterness and little nutritional value may favour the idea of a remedy, but they cannot eliminate the competing explanations. What can be investigated is the chemical evidence and the strength of each proposed route into the calculus.

Ancient DNA revealed poplar and an infected tooth

Laura Weyrich and colleagues later examined dental calculus from El Sidrón and Spy using shotgun sequencing, which reads many DNA fragments rather than searching for only a few predetermined molecules. Fragments are compared with reference genomes to identify organisms associated with the mouth, diet, environment or disease. Five years after the chemical study, the researchers could investigate genetic traces as well as chemical ones. Reliable identification still depends on contamination checks and the limits of the reference comparisons.

The 2017 study in Nature identified differences between individuals from the two sites. Calculus from Spy in Belgium yielded sequences assigned to wild sheep and woolly rhinoceros, consistent with meat consumption in a steppe setting. El Sidrón samples contained signals from pine nuts, mushrooms and moss, without detectable meat DNA in those particular deposits. An absent sequence cannot establish that an individual never ate meat. What becomes preserved in the mouth and remains recoverable tens of millennia later varies substantially among organisms.

One El Sidrón individual had a dental abscess, an infection that creates a pocket of pus around a tooth or adjacent tissue. Such infections may cause severe pain, swelling and difficulty eating, and can spread without treatment. The individual’s calculus also yielded DNA attributed to Enterocytozoon bieneusi, a microsporidian parasite associated with intestinal illness. Poplar DNA and a Penicillium fungus were identified in the same material. Exposure to these organisms and substances in a person who showed disease made intentional symptom relief more plausible than a plant trace alone.

Some species of poplar (Populus) produce salicylate-related chemicals, including salicin, historically used in treatments for pain and fever. Salicin can be converted in the body to salicylic acid. Aspirin is acetylsalicylic acid, a manufactured compound chemically distinct from salicin, so saying that this person consumed aspirin would misrepresent the evidence. DNA cannot show whether bark was eaten, what quantity was involved or whether pain decreased. Contact with poplar is supported; its deliberate medicinal use is inferred.

Penicillium provides even less evidence for treatment. Certain species can produce antibiotic compounds under suitable conditions, but fungal DNA does not reveal penicillin in the sample, a useful dose or a deliberate attempt to give mould as medicine. Material from food or the environment could account for its presence. The 2017 findings do not justify claiming that Neanderthals discovered or administered antibiotics long before laboratory medicine.

The chemical results and later DNA findings should also not be counted as two wholly independent observations of the same treatment. They draw on overlapping archaeological material and use methods that detect different kinds of traces. Compatible results can support an interpretation without establishing intention. Both approaches document illness in an individual whose mouth contained traces of plants with possible therapeutic uses.

Neanderthals knew how to work with plants

Other finds show that Neanderthals used plants for purposes unrelated to treating illness. Starch and phytoliths at Shanidar and Spy point to food, while stone-tool edge wear elsewhere can help identify contact with wood, fresh plants, hides or fibres. Distinctive microscopic polish and damage are useful but rarely identify a particular task beyond doubt. These lines of evidence establish familiarity with plant materials far more directly than they establish organised plant medicine.

At Abri du Maras in southern France, a piece of cord survived against a stone flake in a Middle Palaeolithic deposit. Three fibre bundles had been twisted together, apparently using fibres from the inner bark of a conifer. The 2020 report in Scientific Reports documented a manufactured material requiring selection and separation of fibres as well as twisting them into a stable cord. Its makers understood the properties of a plant material and how to turn it into something useful.

The birch-bark tar recovered at Königsaue in Germany offers different evidence of material knowledge. Patrick Schmidt and colleagues compared Neanderthal-associated tar pieces with modern experimental products and argued in 2023 that an oxygen-limited underground heating process best explained the adhesive. Their experimental and chemical study points to controlled heating and preparation. Though birch tar contains compounds with possible biological activity, these objects were adhesives. Calling them antiseptic dressings would require evidence of that particular use, which the finds do not provide.

Gathering plants for food, making cord and producing adhesives would have exposed Neanderthals to the tastes and effects of many materials. Such experiences might have taught them to recognise irritation or changing symptoms and sometimes to choose a remedy. It cannot reveal whether anyone at El Sidrón intentionally treated a named illness with one of the plants found in their teeth.

Shanidar Cave and the famous flower burial

An older debate about Neanderthal care began with evidence from Shanidar Cave in Iraqi Kurdistan’s Zagros Mountains. In the 1950s and 1960s, Ralph Solecki’s excavations revealed several Neanderthal skeletons. Pollen clusters associated with Shanidar 4 were identified by Arlette Leroi-Gourhan as deriving from several flowering plants. Solecki suggested flowers had been deliberately deposited with the body, and the medicinal associations of some plants encouraged accounts of compassion and herbal knowledge.

The pollen could have arrived by several routes other than a funeral offering, including insects, burrowing animals, wind, water and ordinary vegetation. Chris Hunt, Emma Pomeroy and colleagues reconsidered it in a 2023 reassessment in the Journal of Archaeological Science and argued that solitary bees nesting in the deposits probably produced at least some clumps. They examined other possibilities too, including vegetation deliberately placed over bodies. No bouquet can now be demonstrated, and the pollen gives no reliable evidence for choosing flowers as medicine.

Renewed excavation nevertheless suggests repeated use of the same burial area at Shanidar. Pomeroy and colleagues described another individual in October 2026 in their new study of an individual designated Shanidar A. The body had been deposited about 75,000 years ago within the cluster and was later disturbed by flooding. Researchers recorded an old facial injury and a perforated shoulder blade they interpreted as possible penetrating trauma near death. What caused the fatal injury is unclear. Survival of the earlier facial damage may point to assistance from others, but the skeleton cannot establish which medicines, if any, were used.

Shanidar 1, found during the earlier excavations, lived despite considerable impairment, including serious injury to an arm and other physical damage. The case is important to discussions of Neanderthal social support. Help with obtaining food, moving and remaining safe is a defensible possibility, though both the effects of the injuries and the actions of companions are debated. Surviving injury is evidence relevant to care, not proof of herbal treatment.

What the medicinal compounds might have done

The chemicals in yarrow, chamomile and poplar explain why researchers have considered them possible remedies. Yarrow contains chemicals whose extracts have sometimes shown anti-inflammatory or antimicrobial activity. Chamomile compounds such as apigenin and bisabolol have also been investigated, and salicylates from poplar bark are associated with pain and inflammation. Results from concentrated extracts in laboratories cannot establish an effect from an unknown amount of plant material chewed by a Neanderthal.

The method of preparation would have changed the dose and possibly the action of any active chemical. Raw leaves, dried flowers, heated infusions and pastes may contain different concentrations, which also vary with season, species and local growing conditions. El Sidrón has yielded no evidence allowing archaeologists to distinguish eating, chewing, wound application or contact through other food. A dental abscess gives an obvious reason to seek pain relief but does not preserve the history of attempts to obtain it.

Plants containing pain-relieving substances can also irritate, cause allergic reactions or contain toxins. Modern drug effects cannot simply be projected onto prehistoric use without knowing the dose and preparation. Neanderthals familiar with local plants might sometimes have noticed changes in discomfort and acted on them. Whether the El Sidrón evidence documents such observation remains unproven.

A 2026 tooth study provides different evidence for treatment

A different kind of possible treatment was described by Alisa Zubova and colleagues in May 2026. Their study examined Chagyrskaya 64, a Neanderthal molar from Chagyrskaya Cave in Siberia’s Altai region, dating to about 59,000 years ago. A deep hollow and fine marks on the tooth were interpreted as alterations deliberately made to damaged dental tissue. Using microscopy, three-dimensional imaging and experiments with small stone implements, the researchers tested how comparable traces could be produced. Their open-access study in PLOS One proposes that a pointed stone tool had been used in response to decay or tooth pain.

The Chagyrskaya marks concern a possible physical procedure on a tooth, a different kind of evidence from plant material trapped in calculus. Experimental marks resembling those on the molar strengthen the authors’ case for a deliberate intervention. Still, the proposed purpose and exact method depend on interpreting a single damaged tooth and remain the researchers’ argument, rather than an unquestioned fact. It should not be described as a root canal, which refers to a very different modern clinical procedure.

Much later archaeological evidence for ancient skull surgery illustrates the sort of marks and subsequent healing that can make medical interventions identifiable, although those examples belong to different peoples and times. Chagyrskaya potentially provides a more direct indication of an attempt to alter an injured tooth. It offers no evidence that medicinal plants were used there, and cannot be treated as part of a documented medical tradition connecting that population to El Sidrón.

What can be said about Neanderthal medicine?

The evidence ranges from plant residues to possible tooth treatment, and each find answers a different question. El Sidrón calculus contains chemicals linked with plants, and DNA from an individual with a dental abscess and intestinal parasite includes a signal from poplar. Other dental samples preserve starch and phytoliths, while cord and birch-bark adhesives show skilled use of plant materials. Injured skeletons bear on questions of assistance and care. The Chagyrskaya molar has now prompted a specific, newly published interpretation of dental treatment.

No surviving evidence identifies a designated healer, a written or remembered recipe, the frequency of treatment, or its success. Whether knowledge passed between generations is also unknown. Medicinal plant use is a plausible reading of some Neanderthal finds, especially the El Sidrón association between illness and plant traces, but direct proof of an individual treatment remains absent and competing explanations deserve attention.

Neanderthals plainly possessed more knowledge of plants than older stereotypes allowed. Archaeology has yet to establish securely when they used that knowledge to relieve illness. The calculus residues and the injured tooth offer rare insights into individual lives, while leaving the people’s choices, intentions and outcomes only partly accessible.