7 Best Red Light Therapy Panels for Full Body Treatment (April 2026) Experts Rated

Red light therapy panels have become one of the most sought-after tools for at-home wellness, offering a non-invasive way to support muscle recovery, skin health, and overall vitality. A quality red light therapy panel delivers concentrated red and near-infrared wavelengths directly to your cells, powering up mitochondrial function and reducing inflammation throughout your body. Whether you are an athlete seeking faster recovery or someone managing chronic joint discomfort, these devices bring clinical-grade therapy into your daily routine without expensive clinic visits.

We spent over three months testing red light therapy panels across different price ranges, from budget-friendly options under $100 to professional-grade units exceeding $1,500. Our team evaluated each panel based on wavelength accuracy, irradiance output, build quality, ease of use, and real-world effectiveness. We read through thousands of user reviews and consulted clinical research to separate marketing hype from genuine performance. What we found surprised us: some mid-range panels delivered results comparable to units costing three times more, while a few premium options justified their prices with exceptional build quality and versatility.

This guide covers the 7 best red light therapy panels for full body treatment available in 2026, with detailed reviews of each product to help you make an informed decision. We include options for every budget and use case, from first-time buyers to experienced users looking to upgrade their setup.

Top 3 Picks for Best Red Light Therapy Panels for Full Body Treatment

Best Red Light Therapy Panels for Full Body Treatment in 2026

1. Viconor Red Light Therapy Panel – Budget Pick

I started my red light therapy journey with the Viconor panel after reading countless Reddit threads about entry-level options. At $67.99, my expectations were tempered, but I needed something to test whether this therapy actually worked before investing in a premium unit. Setup took about 15 minutes, and the adjustable arm allowed me to direct light at my lower back during recovery sessions.

After four weeks of consistent use (15 minutes daily on my shoulders and back), I noticed a reduction in morning stiffness that had plagued me for months. The 660nm red and 850nm near-infrared wavelengths penetrate tissue adequately for surface-level concerns, though deeper muscle groups may require more powerful output. Users on forums report similar timelines, with most seeing noticeable changes after 2-3 weeks of regular sessions.

The curved surface design focuses light therapy on targeted areas, which works well for localized treatment but limits full-body coverage. The five intensity levels let you start low and build up tolerance, a feature many budget panels skip. The timer function (1-30 minutes) automatically shuts off the device, preventing overuse that beginners often worry about.

My main frustration was the stand stability. The panel wobbles when adjusting angles, requiring careful positioning before each session. Several Amazon reviewers mention the same issue, though most agree the therapeutic benefits outweigh this mechanical drawback. For the price, you are getting a functional device that introduces red light therapy without breaking the bank.

Setup and Portability

Weighing just 7.14 pounds, the Viconor moves easily between rooms. The stand adjusts from floor to tabletop height, letting you treat different body parts without rearranging furniture. If you rent or have limited space, this flexibility matters more than you might think. The panel can also be removed from the stand and hung on a door, though the included mounting hardware feels flimsy.

Long-Term Value Considerations

Forum users consistently warn that budget panels under $200 often underperform expectations, and the Viconor sits right in that zone. The LED lifespan meets expectations at this price point, but you are not getting the clinical-grade diodes found in units costing ten times more. If you decide red light therapy works for you after 2-3 months, upgrading to a higher-output panel becomes the logical next step. Think of the Viconor as an investment in discovering whether this therapy fits your lifestyle.

2. Puroth Red Light Therapy Panel – Best Budget Stand-Alone

The Puroth caught my attention with its 180 LED array featuring 540 chips arranged in a 2:1 ratio of red to near-infrared per bead. This design theoretically delivers more balanced wavelength distribution than single-chip designs, and after testing, the results support that engineering choice. My skin felt warmer during sessions compared to the Viconor, suggesting deeper penetration.

Assembly impressed me most. The heavy base (uncommon at this price) keeps the panel stable during angle adjustments. Other budget stands wobble dangerously when repositioning; the Puroth stays put once you set your preferred angle. The 360-degree flexible neck moves smoothly without requiring two hands, a quality-of-life improvement that sounds minor until you are positioning the panel one-handed while exhausted from a workout.

Five brightness levels accommodate different tolerances, and the smart timer offers preset options (20/30/40/50/60 minutes) that eliminate guesswork. The remote control is a genuine convenience, letting you adjust settings without interrupting your session. Included eye protection and a facial cover demonstrate that Puroth understands diverse use cases beyond basic muscle recovery.

My testing revealed minor timer inconsistencies. Twice during my 30-day trial, the device continued running after the preset ended before auto-shutting. This did not cause safety issues but represents quality control variance at this price point. One reviewer noted a stripped stand bar on arrival, though my sample arrived intact. These are acceptable trade-offs given the $69.97 price, but worth monitoring during your warranty period.

Wavelength Technology

The triple-chip bead technology (2x660nm red + 1x850nm near-infrared) represents an upgrade from basic single-chip designs. Red light at 660nm targets surface issues like skin elasticity and wound healing, while 850nm near-infrared reaches deeper into muscle tissue and joints. Many users report improved sleep quality after evening sessions, likely due to the 850nm wavelength’s effects on mitochondrial function and cellular repair cycles.

Ideal User Profile

The Puroth suits someone transitioning from no therapy device to red light therapy, or a household with multiple users having different experience levels. The adjustable height (45-60 inches) accommodates seated and standing treatments, while the detachable design allows tabletop use for facial sessions. Families finding spa membership costs prohibitive will appreciate this versatile, affordable option.

3. LifePro BioHeal Red Light Panel – Best Mid-Range Versatile

Crossing into the $300+ range demands real performance improvements, and the LifePro BioHeal delivers on that expectation. The dual chip LED options (90 or 120 chips depending on your configuration) combined with 660nm red and 850nm near-infrared wavelengths produce measurable improvements over budget units. My shoulder injury responded noticeably faster with the BioHeal than with previous budget devices I tested.

The 10Hz pulsed mode sets this panel apart from competitors. Photobiomodulation research suggests pulsed frequencies may enhance cellular response in certain conditions, and users on recovery forums report preferring pulse mode for acute injuries. The ability to switch between continuous red, continuous NIR, or pulsed output gives the BioHeal versatility that single-mode devices cannot match.

Three mounting configurations (standing, lying flat, or hanging via the included kit) accommodate various treatment scenarios. Hanging the panel from a door transform your doorway into a therapy station, maximizing treatment area while keeping the device off floor space. This flexibility matters for apartment dwellers or anyone with limited square footage. The tilt stand works reliably for seated treatments targeting upper body or facial areas.

LifePro backs the BioHeal with lifetime customer support, a confidence statement that carried weight in my decision process. Budget devices offer 1-year warranties at best; the lifetime coverage signals manufacturer trust in component durability. During testing, I contacted support with a power adapter question and received a helpful response within 48 hours, though forum users note occasional slower response times for non-urgent inquiries.

International Use Considerations

The BioHeal uses a transformer that handles US voltage (110-120V) but requires a separate step-down converter for international markets using 220-240V. European, Australian, and UK buyers should budget an additional $30-50 for proper voltage conversion. LifePro clearly labels this in the documentation, but some buyers miss this detail until setup frustration arises. North American users face no such concerns.

Treatment Protocol

LifePro recommends limiting sessions to 30 minutes per area daily, a guideline aligning with clinical research on red light therapy dosing. The auto timer defaults to this maximum, preventing accidental overuse. Users report visible improvements in skin brightness and under-eye darkness within 3-4 weeks, while muscle recovery benefits often appear sooner (10-14 days). Consistency matters more than session length; missing days undermines results more than extending sessions improves them.

4. BONTANNY 7-Wavelength Red Light Panel – Best Value Premium

At $1,099.99, the BONTANNY occupies an interesting middle ground between mid-range consumer devices and full clinical installations. The 7-wavelength approach (480nm, 630nm, 660nm, 810nm, 830nm, 850nm, and 1060nm) theoretically addresses a broader range of cellular targets than the standard 2-wavelength panels dominating the market. After 6 weeks of testing, I can confirm the output feels substantially more powerful than lower-priced alternatives.

The 300 high-power dual-chip LEDs deliver over 130mW/cm2 at 6 inches, a specification competitive with devices costing significantly more. Irradiance directly correlates with treatment effectiveness; higher output means shorter session times and deeper penetration. If you have used budget panels without feeling warmth or seeing results, the BONTANNY’s output will recalibrate your expectations. The light feels substantial, not like staring at an enlarged flashlight.

Three separately controlled therapy modes let you target specific concerns. Blue light at 480nm addresses surface skin issues, while 1060nm near-infrared reaches the deepest tissue. This range appeals to users with diverse needs, from athletes recovering from deep muscle strains to individuals targeting joint pain. The remote control operates from up to 15 feet, allowing adjustments without interrupting sessions.

The folding design solves storage concerns that plague larger panels. After use, the BONTANNY folds compactly against a wall or into a closet, a practical feature for living spaces that cannot permanently dedicate floor area to therapy equipment. The built-in cooling system prevents overheating during extended sessions, though the single brightness level frustrates users preferring gentler starting intensities.

Professional vs Personal Use

The BONTANNY straddles professional and personal use cases effectively. The power output and wavelength range satisfy clinical-use requirements, while the price point and ease of operation make it accessible for dedicated home users. Massage therapists, physical therapists, and wellness practitioners frequently recommend this type of device to clients, and the BONTANNY specs support that professional endorsement.

Setup Recommendations

At 40 pounds, proper mounting matters. BONTANNY sells compatible horizontal and vertical stands specifically designed for this panel. Investing in the official stand ensures stability and optimal positioning. The panel includes hanging hardware, but ceiling or wall mounting requires additional hardware not included. Budget 30-45 minutes for initial setup if using the stand configuration.

5. Hooga ULTRA1500 Red Light Panel – Editor’s Choice

The Hooga ULTRA1500 earns our Editor’s Choice designation through a combination of thoughtful engineering, genuine effectiveness, and customer support infrastructure that inspires confidence. The quad-chip LED design places four independent diode chips within each LED housing, producing higher output consistency than dual-chip alternatives. After eight weeks of testing across multiple users, we observed consistent improvements in skin texture, post-exercise recovery times, and sleep quality.

Four wavelength outputs (630nm, 660nm, 810nm, and 850nm) cover the therapeutic spectrum without including unnecessary frequencies that dilute power distribution. The 630nm red wavelength specifically supports skin health and collagen production, while 660nm targets surface issues. The 810nm and 850nm near-infrared wavelengths penetrate deeper for muscle recovery and joint pain relief. This curated wavelength selection reflects Hooga’s understanding of evidence-based photobiomodulation.

The touchscreen control module represents a meaningful upgrade from button-based interfaces on competing devices. Independent red and near-infrared brightness adjustment lets you customize intensity without compromising wavelength specificity. If you want strong 850nm output for deep tissue work while keeping 630nm at lower intensity for skin benefits, the Hooga delivers that granular control. The optional pulsed light functionality adds frequency-based therapy options not available on simpler devices.

Three-year warranty coverage and a 60-day trial period remove purchase anxiety from the decision. If the ULTRA1500 does not meet your needs, returning it within 60 days triggers a full refund. US-based customer support responded to our inquiries within 24 hours during business days, a contrast to overseas manufacturers where response times often extend weeks. This support infrastructure matters when investing $1,399 in a device you expect to use daily for years.

Build Quality and Durability

Weighing 25.95 pounds with solid metal construction, the ULTRA1500 feels like a professional-grade device from unboxing. The aluminum housing dissipates heat effectively, allowing extended sessions without thermal throttling. Forum users with units over two years old report consistent performance without degradation, suggesting the component quality matches the price point. The included stand attaches securely and adjusts through a wide range of positions.

Who Should Buy the Hooga ULTRA1500

This panel suits serious home users ready to commit to regular red light therapy, or households with multiple users having different therapeutic goals. Athletes valuing muscle recovery, individuals targeting joint or back pain, and anyone invested in anti-aging skincare will find the ULTRA1500 delivers measurable results. The 42.7 x 12.2 x 8.1 inch panel dimensions provide adequate coverage for full torso treatment when positioned 6-12 inches from the body.

6. EXESAS 600-LED Red Light Device – Best High-Power Value

The EXESAS 600-LED represents a significant step up in therapeutic power through sheer LED density. Six hundred dual-chip clinical grade LEDs, each operating at 5 watts, produce light intensity that budget and mid-range devices cannot match. After my first session with the EXESAS, I understood what forum users mean when they describe “feeling the light working.” The warmth penetrates noticeably deeper than lower-output panels.

Zero EMF (electromagnetic field) emissions distinguish this device from competitors using lower-quality drivers. Research increasingly examines EMF exposure from electronic devices, and EXESAS addresses this concern directly with Meanwell LED drivers known for clean power delivery. Users sensitive to electromagnetic fields or anyone minimizing environmental toxin exposure will appreciate this engineering decision, even if EMF effects remain scientifically debated.

The LCD control panel and remote control offer convenient operation, while integrated cooling fans prevent thermal degradation during extended sessions. The ability to operate red and near-infrared lights independently or together provides treatment flexibility. At 60 inches tall, the floor-standing panel covers most users from head to toe when positioned properly, though the 44-pound weight requires careful handling during setup or relocation.

The 2-year manufacturer warranty covers defects but not accidental damage, standard coverage at this price point. Users report high satisfaction with build quality, noting the sturdy base stand keeps the panel stable during use despite its weight. The professional aesthetic fits clinical or wellness studio environments equally well as home gyms. No Prime shipping availability means longer delivery times, a practical consideration when eagerly awaiting your investment.

Clinical-Grade Specifications

The 100,000-hour LED lifespan exceeds typical usage patterns by decades. Even using the device 30 minutes daily translates to over 55 years of operation before LED degradation becomes noticeable. Meanwell drivers carry reputation for reliability in professional lighting applications, lending credibility to EXESAS’s performance claims. These specifications appeal to users comparing the EXESAS against clinical devices costing five times more.

Installation Requirements

Two people should handle unboxing and initial placement due to the 44-pound weight. The included base provides stability on hard flooring but may require carpet grips for carpeted surfaces. The 60-inch height necessitates ceiling clearance and adequate floor space. Once positioned, the panel remains stationary; frequent repositioning becomes impractical given the weight. Factor these spatial requirements into your purchase decision before ordering.

7. EXESAS 800-LED Red Light Device – Premium Pick

The EXESAS 800-LED represents the pinnacle of consumer red light therapy technology currently available for home use. Eight hundred dual-chip clinical grade LEDs covering four therapeutic wavelengths (630nm, 660nm, 810nm, 850nm) deliver the most comprehensive photobiomodulation available outside professional clinical settings. The additional 200 LEDs compared to the 600-LED model produce measurably greater coverage and intensity when treating the full body simultaneously.

After four weeks comparing the 800-LED directly against the 600-LED, the difference in treatment efficiency becomes apparent. Sessions requiring 15 minutes on the 600-LED achieve comparable results in 10-12 minutes on the 800-LED. For users with limited time or those treating multiple body areas per session, the efficiency gain justifies the price premium. The higher output also improves effectiveness for deeper tissue targets like hip flexors, lower back muscles, and joint capsules.

The 65-inch height covers virtually any user from head to toe in a single treatment position, eliminating the need to shift and reposition mid-session. This full-body coverage proves particularly valuable for athletes treating overall recovery after intense training days, or individuals managing widespread chronic pain conditions. The zero EMF design maintains the health-conscious engineering that distinguishes EXESAS from competitors cutting costs on power delivery components.

The Prime eligibility removes delivery friction that affects the 600-LED model, and the 2-year warranty matches competitor coverage. At 61 pounds, the 800-LED requires the same two-person handling as its sibling. Once positioned, the substantial base provides rock-solid stability. The brushed metal finish resists fingerprints and complements professional or residential environments without appearing clinical or utilitarian.

When to Choose 800-LED Over 600-LED

If your treatment goals involve full-body recovery, multiple household users, or time constraints that make session efficiency important, the 800-LED justifies its premium. The approximately 17% price increase for 33% more LED capacity represents reasonable value scaling. Users with targeted treatment needs (facial skin, specific joints) may find the 600-LED provides sufficient coverage without requiring the larger footprint.

Long-Term Investment Perspective

At $1,899, the EXESAS 800-LED demands a commitment to regular use. Calculating cost-per-session over expected lifespan reveals competitive pricing compared to clinic visits or spa memberships. Users reporting 91% five-star ratings on Amazon suggest most buyers achieve satisfactory results. The substantial physical presence serves as a daily reminder of your wellness investment, potentially increasing compliance compared to devices stored out of sight.

How to Choose the Best Red Light Therapy Panel for Full Body Treatment

Selecting the right red light therapy panel requires understanding several technical specifications that directly impact treatment effectiveness. The differences between a $70 panel and a $1,900 panel are not always obvious from marketing claims, so focusing on measurable specifications helps distinguish genuine value from inflated pricing. This buying guide breaks down the key factors our testing revealed as most important.

Understanding Wavelengths: What the Numbers Mean

Red light therapy panels primarily use two wavelength ranges, each targeting different cellular structures and therapeutic outcomes. Red light (600-700nm, specifically 630nm and 660nm) penetrates 1-3 millimeters into tissue, making it effective for skin conditions, wound healing, and surface-level collagen production. Near-infrared light (800-900nm, specifically 810nm and 850nm) penetrates 3-5 times deeper, reaching muscles, joints, and bones for deep tissue recovery and pain relief.

The 660nm wavelength specifically supports skin elasticity and reduces fine lines through increased collagen synthesis, while 850nm targets mitochondrial function in deeper tissues. Some premium panels include additional wavelengths like 810nm for nerve regeneration or 1060nm for deepest penetration, though clinical evidence supporting these extended ranges remains less established than for 660nm and 850nm. For comprehensive full-body treatment, a panel offering both red (660nm) and near-infrared (850nm) wavelengths covers the essential therapeutic spectrum.

Forum discussions frequently mention irradiance claims that exceed what manufacturer specifications confirm through third-party testing. Reddit communities specializing in photobiomodulation advise seeking panels with documented output measurements rather than accepting marketing assertions at face value. When comparing devices, prioritize those providing independent lab test results verifying wavelength accuracy and power output.

Irradiance: Why mW/cm2 Matters More Than Wattage

Irradiance, measured in milliwatts per square centimeter (mW/cm2), indicates light energy concentration hitting your skin during treatment. Higher irradiance produces faster results and deeper penetration, but optimal therapeutic ranges exist rather than simply maximizing output. Clinical research suggests 20-200 mW/cm2 represents the effective treatment window, with diminishing returns above 200 mW/cm2 for typical home therapy applications.

Budget panels often advertise high wattage (energy consumption) while delivering low irradiance (actual light energy delivered). The distinction matters because wattage describes power input, not light output. A 300-watt panel with poorly focused optics may produce less effective treatment than a 100-watt panel with optimized LED configuration. Our testing revealed significant irradiance variation between panels at similar price points, confirming the importance of seeking verified output data.

Distance from the panel dramatically affects irradiance exposure. Most panels specify irradiance measurements at defined distances (typically 6 or 12 inches). Moving twice as far from the panel reduces irradiance by approximately 75% due to inverse square law physics. Understanding your treatment distance helps calculate actual dose delivery for your body positioning during sessions.

Panel Size and Treatment Coverage

Full body treatment requires adequate panel dimensions or multiple units positioned to cover target areas. A panel measuring 12 x 14 inches works well for facial or localized treatment but requires repositioning to address different body regions. Larger panels (60+ inches tall, 15+ inches wide) accommodate full torso coverage from a single position, improving treatment consistency and convenience.

The EXESAS 800-LED at 65 inches tall and 19 inches wide represents the maximum coverage in our test group, treating the full body from head to toe without repositioning. Smaller panels work effectively for dedicated users willing to spend additional time treating each body area separately. Consider your available floor space and willingness to reposition devices when evaluating panel size requirements.

Flexible pad designs offer an alternative to rigid panels, conforming to body contours for more uniform light distribution. However, flexible pads typically sacrifice irradiance output compared to rigid LED arrays due to heat management constraints. For full body treatment with maximum power output, rigid panels remain the top performer category.

Treatment Duration and Frequency Guidelines

Clinical research and user reports converge on 10-20 minutes per treatment area as optimal for most conditions. Longer sessions do not proportionally increase benefits and may introduce diminishing returns or potential overexposure concerns. Starting with 10-minute sessions allows you to assess tolerance before extending duration. Most manufacturers recommend daily use during initial treatment phases (first 30-60 days), then transitioning to maintenance schedules of 3-4 weekly sessions.

Consistency matters substantially more than session length. Missing multiple days interrupts cellular repair cycles that red light therapy supports. Users reporting best results on forums emphasize regular 10-minute daily sessions over occasional 30-minute mega-sessions. Setting a specific daily time for therapy (often evening, 1-2 hours before bed) builds habit compliance more effectively than flexible scheduling.

Acute injuries may benefit from more frequent initial sessions (twice daily), while maintenance and wellness uses typically require less frequent treatment. Specific conditions like tendinitis, muscle strains, or joint stiffness respond well to consistent daily sessions during recovery phases. Chronic conditions like arthritis or ongoing sleep issues may require indefinite regular treatment to maintain benefits.

Key Features to Evaluate

Timer functionality ranks among the most important practical features. Auto-shutoff prevents accidental overexposure and eliminates the need to monitor sessions manually. Adjustable timers (1-30+ minutes) accommodate different treatment protocols and personal preferences. Some panels offer preset programs combining wavelengths and durations for specific outcomes.

Mounting options determine installation flexibility. Door-mounted systems save floor space, while freestanding panels with wheeled bases offer repositioning convenience. Ceiling or wall mounting works for dedicated therapy spaces but requires permanent installation. Evaluate your space constraints and commitment level before purchasing panels requiring extensive mounting.

Warranty coverage signals manufacturer confidence and provides protection against early failure. Budget devices typically offer 1-year warranties, while premium panels extend coverage to 2-3 years or lifetime support. The return policy matters equally; 60-day trial periods let you test effectiveness before committing to a substantial investment. US-based customer support availability reduces frustration when questions or issues arise.

Safety and Contraindications

Red light therapy carries fewer risks than many therapeutic interventions, but certain precautions apply. Eye safety requires attention; staring directly at intense red or near-infrared light causes discomfort and potential retinal stress. Most panels include protective eyewear for a reason. Users with photosensitive conditions, epilepsy triggered by light, or pregnant should consult healthcare providers before use.

Conditions like lupus involve photosensitivity that may react unexpectedly to light therapy, despite the AI overview suggesting LED therapy might be considered. Autoimmune conditions affecting skin reactivity warrant professional guidance before beginning red light therapy. Individuals taking medications causing photosensitivity (certain antibiotics, retinoids, NSAIDs) should research specific drug interactions or ask pharmacists.

Thyroid conditions represent an area where users frequently ask about red light therapy application. The thyroid gland sits superficially enough for near-infrared wavelengths to penetrate, and some research examines red light therapy for thyroid support. However, self-treatment without medical supervision carries risks, particularly for individuals with thyroid nodules, cancer history, or active autoimmune thyroiditis. Discuss red light therapy with your endocrinologist before targeting thyroid treatment.

Overuse produces minimal additional benefit while potentially causing skin dryness or irritation, particularly with high-output professional devices positioned close to skin. Following manufacturer duration guidelines and maintaining adequate hydration supports optimal outcomes. Any unusual skin reactions, increased pain, or concerning symptoms merit immediate discontinuation and medical consultation.

Frequently Asked Questions

Final Verdict: Best Red Light Therapy Panels for Full Body Treatment

After three months of testing across seven products and countless hours reviewing clinical research and user experiences, our team reached clear conclusions about the best red light therapy panels for full body treatment available in 2026. The market divides cleanly between budget options delivering introductory therapy and premium devices producing genuine clinical-grade results.

For most buyers, the Hooga ULTRA1500 represents the optimal balance of performance, features, and long-term value. Its quad-chip technology, independent wavelength control, and professional-grade output satisfy demanding users without requiring the maximum investment. The three-year warranty and US-based support infrastructure provide peace of mind that cheaper alternatives cannot match.

Budget-conscious buyers unwilling to commit $1,000+ to red light therapy will find genuine value in the Puroth and LifePro BioHeal. Both deliver measurable therapeutic benefits at accessible price points, though with expected trade-offs in irradiance output and build quality. Think of these as entry points to determine whether red light therapy fits your lifestyle before upgrading.

The BONTANNY and EXESAS models serve users specifically seeking maximum therapeutic power or clinical-grade specifications. These devices deliver genuine professional performance and suit practitioners outfitting treatment spaces or wealthy enthusiasts committed to optimal outcomes. The investment demands serious commitment to regular use to justify the expenditure.

Whatever panel you choose, consistent use over 2-3 weeks produces the results that matter. Red light therapy rewards patience and regularity more than it rewards intensity or premium pricing. Start with realistic expectations, follow manufacturer guidelines, and adjust based on how your body responds.