Quick Answer:

Grounding sheets have not been convincingly proven to lower cortisol. A small pilot study reported reduced nighttime cortisol during grounded sleep, but stronger controlled research is needed to establish whether grounding sheets cause this effect or provide meaningful benefits.

What does cortisol have to do with sleep and stress?

Cortisol is often called the “stress hormone,” but it also helps regulate energy, blood pressure, and immune function. Understanding its normal pattern puts claims about grounding sheets and cortisol into context.

Cortisol follows a daily rhythm

For people with a typical nighttime sleep schedule, cortisol begins rising before waking, reaches its highest levels around the morning, and gradually declines throughout the day. It normally reaches very low levels around midnight. This daily rhythm helps prepare the body for activity and differs from the temporary increases that occur in response to stress.

Lower cortisol is not always the goal

Your body needs cortisol to function. The goal is appropriate regulation—not keeping levels as low as possible throughout the day. A normal morning rise serves a useful purpose, while low nighttime levels are part of the usual daily pattern.

That distinction matters when evaluating grounding research: a reported decrease in nighttime cortisol is a specific finding. It should not be interpreted as proof that lowering cortisol at every hour would improve health.

What does the grounding and cortisol study actually show?

A frequently cited study on grounding and cortisol was published in 2004 by Maurice Ghaly and Dale Teplitz in The Journal of Alternative and Complementary Medicine. It investigated whether sleeping grounded was associated with changes in cortisol, sleep, pain, and stress. The findings were encouraging, but the study’s design limits what we can conclude.

How the study was conducted

The pilot study followed 12 adults who reported sleep problems, pain, and stress. Participants slept in their own beds using a conductive mattress pad connected to the earth.

What the researchers reported:

At the six-week follow-up, midnight cortisol was lower in eight of the 12 participants. At 8 a.m., cortisol was higher in 10 participants. The authors interpreted the overall pattern as trending toward a more typical daily rhythm.

Participants also reported improvements: 11 said they fell asleep faster, all 12 reported fewer nighttime awakenings, and nine reported less emotional stress. These were self-reported experiences rather than independently measured sleep outcomes.

Why these findings are preliminary

The main limitation is the absence of a separate control group using an otherwise identical, ungrounded pad. Everyone received the grounding intervention, so the study could not establish what would have happened without it.

That matters because a before-and-after change can have several explanations. Natural variation, changes in daily routines, expectations, or symptoms returning toward their usual levels could contribute. These possibilities do not prove the findings were caused by something else; they explain why a controlled comparison is necessary.

The small sample also makes it difficult to generalize the results. Individual responses can substantially affect the overall picture, and one follow-up sampling day cannot establish whether changes persist over months or years.

The study provides a preliminary signal worth investigating—not firm proof that grounding sheets reliably lower cortisol. It also does not establish that cortisol changes caused the reported sleep improvements, or that a particular commercial sheet will produce the same results.

Does newer grounding research strengthen the cortisol claim?

Sleep research and cortisol research answer different questions

“Total sleep time in the Experimental group was significantly increased compared to the Control group (P < 0.05).”

A 2025 randomized, double-blind, placebo-controlled study adds newer evidence about grounding and sleep. Researchers assigned 60 participants to grounded or non-grounded mats for at least six hours daily over 31 days. They assessed sleep quality, insomnia, daytime sleepiness, and perceived stress through questionnaires, alongside actigraphy to estimate total sleep time. They did not measure cortisol.

The results were mixed. Actigraphy-estimated sleep time favored the grounding group, but end-of-treatment questionnaire scores did not differ significantly between groups.

The authors reported a favorable insomnia finding at day 38, although baseline insomnia scores were already different. Improvements within the grounding group therefore should not automatically be interpreted as improvements beyond placebo.

The paper’s discussion of reduced nighttime cortisol refers to earlier research, including the 2004 study—not new hormone measurements. Better sleep or lower perceived stress cannot independently confirm a cortisol reduction.

Funding also deserves attention: World Home Dr., which supplied the mats, and Geosan funded the research. Author affiliations included World Home Doctor and DF World; the authors declared no known competing interests.

This trial offers preliminary sleep-related findings, but it does not directly strengthen the claim that grounding sheets lower cortisol. That question requires controlled studies that actually measure the hormone.

What should you consider before trying a grounding sheet?

Before trying a grounding sheet, check how the product should be used and what you realistically expect from it. This short checklist can help:

• Read the setup and contact instructions. Follow the manufacturer’s guidance on placement, skin contact, and compatible bedding. Instructions for one sheet may not apply to another.
• Verify the required connection. Use the manufacturer’s recommended testing method. An outlet tester and a sheet conductivity tester check different parts of the setup; neither demonstrates a cortisol reduction.
• Assess comfort and usability separately. Fabric softness, fit, washing requirements, and ease of setup matter when choosing bedding. Those qualities do not establish that a sheet’s medical claims are supported.
• Keep expectations realistic. Preliminary findings are not a guarantee of results. If you track your experience, record other changes in your routine that could influence how you feel.
• Get appropriate care when needed. Persistent sleep problems or suspected hormone disorders deserve medical evaluation. A grounding sheet should not delay that assessment.

For more on connection-related precautions, read our guides to grounding-sheet electrical safety.

Frequently asked questions

Is grounding scientifically proven to lower cortisol?

Grounding has not been convincingly proven to lower cortisol. A small uncontrolled pilot study reported changes in nighttime cortisol during grounded sleep, but its design could not establish cause and effect. Larger, well-controlled studies are needed to determine whether the effect is reliable.

Do grounding sheets lower cortisol immediately?

An immediate cortisol-lowering effect has not been established. The frequently cited pilot study repeated cortisol testing after six weeks, rather than measuring an immediate response. Feeling relaxed shortly after using a grounding sheet does not demonstrate that your cortisol levels have changed.

Can grounding sheets help with stress without lowering cortisol?

You may feel calmer while using a grounding sheet without knowing whether your cortisol changed. Comfort, expectations, and a relaxing bedtime routine could contribute to that experience. A subjective improvement is worth recording, but it does not establish a hormonal effect or prove grounding caused it.

Does better sleep mean my cortisol levels are lower?

Better sleep alone cannot confirm lower cortisol. Sleep quality is influenced by many factors, and cortisol naturally changes throughout the day and night. Sleep diaries, wearable sleep scores, and morning energy levels do not directly measure cortisol or establish that a grounding sheet altered it.

Are grounding mats or sheets better for lowering cortisol?

There is no established evidence that grounding mats outperform grounding sheets, or vice versa, for lowering cortisol. Findings from one type of grounding equipment do not establish another product’s effectiveness. A reliable comparison would require a study directly testing both options under comparable conditions.

Can grounding sheets treat high cortisol or Cushing’s syndrome?

Grounding sheets are not an established treatment for high cortisol or Cushing’s syndrome. The small grounding studies do not demonstrate that they treat an endocrine disorder. If you have diagnosed or suspected cortisol abnormalities, seek medical evaluation and follow your clinician’s treatment plan.

Our final recommendation

Research on grounding sheets and cortisol remains preliminary. A small pilot study reported nighttime cortisol changes during grounded sleep, but that does not establish a reliable treatment effect or prove that commercial sheets will produce similar results. If you choose to try one, keep expectations modest: feeling calmer or sleeping better cannot confirm a cortisol reduction. Before purchasing, review our grounding-sheet research guide for a broader look at the evidence, study limitations, and claims worth examining carefully.