Grounding and Blood Viscosity: What the Research Shows
The short answer
Small human studies have reported measurable changes in red blood cell electrical properties, red blood cell aggregation and whole-blood viscosity during or after grounding.
One experiment involving 10 adults found that after two hours of grounding, red blood cells carried a substantially greater negative zeta-potential magnitude and showed less large-cell aggregation. A later controlled study directly measured whole-blood viscosity and found significant decreases from baseline in the grounded group, but not in the sham-grounded group. A third pilot study reported different patterns of superficial facial blood flow during grounding.
These are interesting physiological findings because they involve objective measurements rather than simply asking participants whether they felt different.
But the research remains preliminary. The studies were small, independent replication is lacking, and the findings do not establish that grounding prevents cardiovascular disease or improves cardiovascular outcomes.
So what exactly happened to the blood?
Why red blood cell behaviour matters
Red blood cells, or erythrocytes, normally carry a negative electrical charge at their surface. One way researchers describe this electrical characteristic is through zeta potential.
In simple terms, similarly charged cells repel one another. A greater negative surface-charge magnitude can therefore help keep red blood cells separated rather than aggregated together.
Red blood cell aggregation is only one of several factors that influence how blood flows. Blood viscosity also depends on factors including haematocrit, plasma characteristics, cell deformability and shear rate. So changes in red blood cell charge or aggregation should not automatically be treated as equivalent to a direct measurement of whole-blood viscosity.
That distinction becomes particularly important when looking at the first grounding experiment.
The 2013 study: grounding and red blood cell electrical charge
In 2013, Chevalier and colleagues published a pilot study examining what happened to red blood cells after two hours of grounding.
Ten healthy adults, with an average age of 54.9 years, participated. Conductive patches were placed on the palms of their hands and soles of their feet and connected by wire to a stainless-steel rod inserted into the ground outdoors.
Blood samples were taken before grounding and again after two hours while participants were still grounded. The researchers examined two main things: electrophoretic mobility, which describes how the red blood cells moved through an applied electrical field, and red blood cell aggregation, or how the cells grouped together. Zeta potential was then calculated from the electrophoretic measurements.
What happened to zeta potential?
The change was notable.
Before grounding, the participants' mean zeta potential was −5.28 mV. After two hours of grounding, it was −14.3 mV.
Because zeta potential is negative, the important finding is the increase in its absolute magnitude: on average, it became approximately 2.70 times greater. Every one of the 10 participants showed a change in this direction. The paper reported a one-tailed p-value of approximately 0.00036 for the zeta-potential change.
In practical terms, the red blood cells displayed greater negative electrical characteristics after the grounding session.
What happened to red blood cell aggregation?
The microscopy findings also changed.
After grounding, the samples contained significantly more individual red blood cells and two-cell groupings and fewer three-cell groupings.
The number of cells found in groups of four or more fell from an average of 34.7 per 100 cells before grounding to 15.0 after grounding. The researchers did not perform a statistical significance test on this 4+ category because those data did not meet their normality criterion.
Overall, the microscopic samples showed less large-cell aggregation after two hours of grounding.
That combination — a larger negative zeta-potential magnitude together with reduced aggregation — is what made the study scientifically interesting.
An important distinction: the 2013 study did not directly measure blood viscosity
This is easy to miss because the paper itself was titled Earthing (Grounding) the Human Body Reduces Blood Viscosity—a Major Factor in Cardiovascular Disease.
However, the researchers did not take whole blood and directly measure its viscosity using a viscometer.
They measured red blood cell movement, calculated zeta potential and examined aggregation. Those measurements are relevant to blood rheology, and the researchers interpreted the changes as consistent with reduced viscosity.
That is not quite the same thing as directly demonstrating a change in whole-blood viscosity.
Fortunately, a later experiment attempted to investigate exactly that.
The 2015 study: researchers measure whole-blood viscosity directly
Brown and Chevalier studied 28 healthy women aged 35–65, divided evenly between grounded and sham-grounded conditions.
Participants completed one hour of gentle yoga consisting of five 12-minute sequences. They randomly selected yoga mats that were either connected to ground or sham-grounded, and the study was conducted using a double-blind design.
Blood was collected before and after the session and analysed using a scanning capillary viscometer, providing a direct measurement of whole-blood viscosity.
What did the study find?
At the higher shear rate, mean viscosity in the grounded group fell from 39.1 to 38.5 millipoise.
At the lower shear rate, it fell from 120.7 to 116.9 millipoise.
Both changes were statistically significant compared with the grounded group's own baseline, with reported p-values of 0.032 and 0.031 respectively.
The sham-grounded group moved slightly in the opposite direction: from 38.1 to 38.3 at the higher shear rate and from 115.3 to 117.1 at the lower shear rate. Those changes were not statistically significant.
That makes the results interesting: viscosity decreased significantly during the grounded condition, whereas it did not decrease during the sham condition.
There is, however, an important statistical qualification.
The paper's reported grounded-versus-sham comparisons were themselves not statistically significant. Nor did the researchers report the type of group-by-time interaction analysis that would directly test whether the amount of change in one group was significantly different from the amount of change in the other.
So we cannot accurately say that this study conclusively demonstrated that grounding reduced viscosity more than sham grounding.
What we can say is that a significant reduction occurred within the grounded group, no significant reduction occurred within the sham group, and this provides a promising signal that deserves replication in a larger controlled trial.
A third study looked at blood flow itself
A 2014 study by Chevalier approached the question differently.
Rather than measuring the properties of blood, researchers used laser speckle contrast imaging (LSCI) to observe superficial facial blood flow.
Forty adults were randomly assigned to grounding or sham grounding: 27 were grounded and 13 were sham-grounded. Participants rested in a recliner using a conductive mat, pillow and patches for at least an hour.
The study was double-blind, and the imaging system measured blood-flow changes in approximately the first millimetre of skin.
The researchers reported different patterns between the grounded and sham-grounded participants. Grounded subjects were described as showing rhythmic changes and/or increases in facial blood flow after an initial relaxation period, which the author interpreted as evidence of improved blood-flow regulation.
There is an important limitation, however.
Although 40 people participated, the paper did not publish conventional aggregate statistical results comparing all 27 grounded participants with all 13 controls. Instead, detailed results were presented for three grounded and three sham-grounded participants, which the author described as representative of their groups.
For that reason, this study is best viewed as interesting supporting evidence about superficial microcirculatory patterns, rather than strong confirmation that grounding improves circulation generally.
Do the three studies tell a consistent story?
There is an intriguing pattern across the experiments.
The 2013 study observed an increase in the magnitude of red blood cell zeta potential together with less large-cell aggregation.
The 2015 study then used a different method and directly recorded lower whole-blood viscosity after grounding within the grounded group.
The 2014 experiment, meanwhile, reported changes in superficial facial blood-flow patterns during grounding.
These findings concern related aspects of blood behaviour, and they point broadly in a compatible direction.
But it would go too far to say that one study has proven the mechanism behind another.
The experiments involved different people, different grounding methods and different outcome measurements. The 2013 study also had no sham-grounded control, while the 2015 controlled experiment did not demonstrate a statistically significant between-group treatment effect using the analyses it reported.
The appropriate interpretation is therefore convergence of preliminary signals, rather than confirmation of an established physiological pathway.
How might grounding influence red blood cells?
Researchers in this field have proposed several possible explanations.
The central hypothesis is that electrically connecting the body with the Earth may allow charge to move between them and influence electrical conditions within the body. Researchers have proposed that this could contribute to a more negative electrical environment around red blood cells, increasing electrostatic repulsion and reducing their tendency to aggregate.
Other grounding papers have proposed downstream effects involving oxidative stress, inflammation and autonomic nervous-system regulation.
These ideas are biologically interesting, but the distinction between measurement and mechanism is crucial.
The studies discussed here measured changes in red blood cell behaviour, viscosity or superficial blood flow.
They did not directly demonstrate that electrons from the Earth travelled to red blood cell membranes and caused those changes. Nor did the viscosity experiment directly measure oxidative stress or inflammation as the pathway responsible for the result.
Those remain hypotheses to be tested.
Does this mean grounding "thins the blood"?
That phrase is best avoided.
The 2015 study measured blood viscosity, meaning resistance to flow. That is different from measuring the blood-clotting processes targeted by anticoagulant medications.
Medicines commonly described as "blood thinners", such as warfarin, primarily reduce the blood's ability to form clots; they do not literally make blood thinner in the same sense as a viscosity measurement.
The grounding studies reviewed here therefore do not establish that grounding acts as an anticoagulant, prevents blood clots or should be used in place of cardiovascular medication.
What about grounding mats specifically?
The studies did not all use the same method of grounding.
The 2013 red blood cell experiment used conductive patches attached to the hands and feet and connected to a rod in the Earth.
The 2014 facial blood-flow study used a combination of a conductive mat, pillow and patches connected to the grounding system of an electrical outlet.
Importantly, the 2015 viscosity experiment did directly use grounded yoga mats, with sham-grounded mats serving as the comparison condition.
That makes the 2015 study particularly relevant when considering conductive grounding mats. Even so, results from one specific experimental setup should not automatically be assumed to apply to every grounding product, duration or use pattern.
What are the main limitations?
The biggest issue is not that nothing was found. Something measurable was reported.
The issue is how much confidence we can place in those findings.
The pivotal zeta-potential experiment involved only 10 people and had no sham control. The viscosity trial involved 28 participants and produced encouraging within-group results, but did not establish a statistically significant between-group treatment effect. The facial blood-flow study enrolled 40 people but presented detailed findings from only six individual cases.
There is also substantial overlap among the researchers involved, and all three studies had industry connections. The 2013 study was funded by Earth FX, with three authors disclosing contractor relationships and small shareholdings. The 2015 study was funded by Earth FX, grounding equipment was supplied by Earthing.com, and Chevalier disclosed an Earth FX contractor relationship and shareholding. The 2014 study was also funded by Earth FX, with Chevalier reporting the same relationship.
These factors do not invalidate the measurements. They do strengthen the case for independent replication by researchers without commercial involvement.
So, does grounding affect blood viscosity?
Based on these studies, the fairest answer is:
There is preliminary human evidence suggesting that grounding can be associated with measurable changes in red blood cell electrical properties, red blood cell aggregation and whole-blood viscosity.
The most striking finding came from the 2013 pilot experiment, where the magnitude of red blood cell zeta potential increased by an average factor of 2.70 and large-cell aggregation decreased after two hours of grounding.
The 2015 controlled experiment then provided a separate and important observation: whole-blood viscosity decreased significantly from baseline in participants using grounded yoga mats, while significant decreases were not observed in the sham-grounded group.
Those findings are genuinely interesting.
What they do not yet tell us is whether these changes are consistently reproducible, what biological mechanism produces them, how long they last, or whether they result in meaningful improvements in cardiovascular health.
That is the next step the science needs to answer.
Bottom line
Research into grounding and blood rheology is still at an early stage, but it has produced more than subjective reports.
Researchers have recorded measurable changes in red blood cell electrical characteristics, cellular aggregation and whole-blood viscosity, alongside preliminary observations involving superficial blood flow.
The evidence is not strong enough to conclude that grounding prevents cardiovascular disease, reduces blood-clot risk or delivers established cardiovascular benefits.
But neither is the most accurate conclusion that nothing happened.
Something measurable happened in these experiments. The important question now is whether larger, independently conducted studies can reproduce those findings — and determine whether the observed changes matter for human health.
Research references
Chevalier G, Sinatra ST, Oschman JL, Delany RM. (2013). Earthing (Grounding) the Human Body Reduces Blood Viscosity—a Major Factor in Cardiovascular Disease. The Journal of Alternative and Complementary Medicine, 19(2), 102–110. doi:10.1089/acm.2011.0820.
Chevalier G. (2014). Grounding the Human Body Improves Facial Blood Flow Regulation: Results of a Randomized, Placebo Controlled Pilot Study. Journal of Cosmetics, Dermatological Sciences and Applications, 4, 293–308. doi:10.4236/jcdsa.2014.45039.
Brown R, Chevalier G. (2015). Grounding the Human Body during Yoga Exercise with a Grounded Yoga Mat Reduces Blood Viscosity. Open Journal of Preventive Medicine, 5, 159–168. doi:10.4236/ojpm.2015.54019.
This article is for educational purposes and discusses preliminary research. It is not medical advice and should not be used as a basis for changing prescribed medication or medical treatment.