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Tartar reveals use of euphoriants

The Department of Forensic Medicine at Aarhus University has developed a new method which reveals the use of psychedelics and pharmaceuticals based on a person's teeth.

2021.01.14 | Line Rønn

As little as 1mg of tooth tartar can very precisely reveal a person’s consumption of euphoriants and pharmaceuticals. This can e.g. help archaeologists to identify habits and self-medication among ancient peoples. Photo: Line Staun Larsen


After heroin, cocaine or cannabis disappear from the blood, they can still be found in the tartar on the teeth.

In fact, the use of psychedelics and pharmaceuticals can be traced in the tartar of skeletons several hundred years after the substance was ingested. Researchers from the Department of Forensic Medicine at Aarhus University have made this discovery in collaboration with Dutch archaeologists.

Researchers at the Department of Forensic Medicine have developed a very specific method of analysis which can detect substances in as little as 1 mg of tartar.

As part of the analyses carried out in connection with routine autopsies, the researchers in Aarhus have collected tartar from ten deceased people who have taken various substances.

In total, the researchers discovered 131 findings embedded in tartar from the ten deceased people – which was more than was found in the blood. There was a good correlation between the findings in the deceased's tartar and blood, but the tartar also contained substances such as heroin and the precursor to THC (a psychoactive substance in the hemp plant), which cannot normally be measured in blood samples.

The poor oral hygiene of the past is a bonus today

"The new methods open for new research lines  examining the tartar for pharmaceuticals and drugs using chemical analysis, and it has exciting perspectives," says Professor with special responsibilities Dorthe Arenholt Bindslev from the Department of Forensic Medicine, Aarhus University, who is one of the researchers behind the studies.

The method is particularly interesting from an archaeological point-of-view, as archaeologists have until now been forced to primarily rely on examining jars and pipes, if they wanted to know what ancient peoples used to soothe pain or achieve euphoria. Due to the poor oral hygiene of the past, there is plenty of tartar on archaeological material, and it can now be used to help uncover new information about life style and medication. . It is possible to examine tartar on historical skeletons with bone fractures, root inflammation (tooth ache) or other painful disorders and perhaps suggest how they attempted to alleviate the pain. 

”The studies may elucidate  new aspects of the way of life and the general state of health of ancient peoples, which we today can only guess. Examining Viking skulls for the hallucinating substances that they are believed to have at times taken would be an obvious possibility, including substances from fungi and nightshade plants such as henbane," says Dorthe Arenholt Bindslev.

The method has now been used on the tartar from Dutch skeletons from the 19th century, which turned out to contain several substances – although the results have not yet been published.

Could be used in forensic medicine

Although dental hygiene is significantly better today, the discovery can nonetheless be used in forensic medicine in special cases, such as e.g. when there is a need to look for substances taken longer ago.

"In some cases, people are exposed to toxins that lead to a longer hospitalisation followed by death. In these cases, the substances are no longer present in the blood or urine, and the substances have not yet been embedded in the hair. Following our new convincing results, it is reasonable to hope that it will be possible to find these substances in the tartar," says Senior Researcher Jørgen Bo Hasselstrøm from the Department of Forensic Medicine, Aarhus University.

"Here the method could have a supplementary function. But the big perspective is in archaeology," he says.

The results have been covered in the prestigious American research-oriented news media Science: https://www.sciencemag.org/news/2021/01/tooth-tartar-could-uncover-drug-habits-ancient-people

The research results – more information



Senior Researcher Jørgen Bo Hasselstrøm

Department of Forensic Medicine, Aarhus University

Mobile: (+45) 5124 6112


Professor with Special Responsibilities Dorthe Arenholt Bindslev

Forensic Odontology specialist

Department of Forensic Medicine, Aarhus University

Mobile: (+45) 2026 5192


Research, Health and disease, Academic staff, External target group, Health, Technical / administrative staff, Department of Forensic Medicine, Public/Media, Health