Form factor is the most consequential decision in this category and the one people spend the least time on. Buyers agonize over wavelength counts and irradiance claims, then buy a shape that cannot deliver a useful dose to the thing they care about.
The good news is that the decision is mostly geometry, and geometry is easy to reason about.
The rule
Light that does not land on the target does nothing. Everything else follows from that.
A panel two feet away spreads its output across a wide area, most of which is not the part you want treated. A wrap in contact with your knee puts nearly all of its output into a few square inches of knee. Same brand, same wavelengths, completely different delivered dose.
The published protocols reflect this. Skin trials used broad, even, close-range illumination of the face. Hair trials used devices that sit on the scalp. Pain trials used probes held in contact with specific points around a joint. Nobody in the literature stood a patient across the room from a light and hoped.
Panels
A panel is the general-purpose option. It covers a lot of body at once, which makes it the only practical choice for full-torso sessions or recovery work across large muscle groups.
The trade-off is distance. Irradiance falls off steeply as you move back, and panels are used at six inches to three feet. NovaaLab publishes a distance curve for its pad that illustrates the physics clearly: around 150 mW/cm2 at contact, 120 at one inch, 45 at three inches, 25 at six inches.
The same falloff applies to every panel, which is why the number on the box is only meaningful when paired with a distance. See why irradiance numbers are usually wrong.
Buy a panel if you want whole-body coverage and you have somewhere to put it. Do not buy one expecting it to be the best tool for a specific joint or for your face.
Masks
For facial skin, a mask beats a panel and it is not close.
A silicone mask sits flush against the skin at zero distance, delivers an even dose across the whole face, and requires nothing from you except sitting still. A panel makes you hold a fixed position and lights one plane of your face at a time.
The dose required is also lower than people assume. In the sham-controlled mask trial by Park, Park and Jung published in Medicine (Baltimore) in 2025, the device was capped at 10 mW/cm2 and worn for nine minutes, five times a week. That is about 5.4 J/cm2 per session, and 86.2 percent of the active group showed crow's feet improvement against 16.7 percent of sham users.
Wunsch and Matuschka's 2014 trial in Photomedicine and Laser Surgery, the other study everyone cites, normalized to roughly 9 J/cm2 per session. Neither of these is a high-intensity protocol.
So the mask question is not "which mask has the highest output". It is whether it contours to your face, covers the areas you care about, publishes its peak wavelengths, and whether you will actually wear it. What the research says about skin covers the evidence in full.
Wraps and pads
For a joint or a specific muscle, contact wins. A flexible pad wrapped around a knee or strapped across a lower back holds the emitters against tissue, which is roughly a fivefold intensity advantage over the same device held six inches away.
It also maps onto what the pain trials did. The 2019 BMJ Open meta-analysis by Stausholm and colleagues found that only trials dosing within the World Association for Laser Therapy recommendations beat placebo, and those protocols were specified in joules per treatment spot, applied in contact.
You cannot hit a joules-per-spot target from across a room. What holds up for joint and muscle pain walks through the numbers.
The downside is obvious: you treat one area at a time. A pad is a poor choice if what you want is a whole-body session.
Caps and helmets
Scalp devices are a separate category with separate evidence, and the general-purpose panels do not substitute for them.
The clinical work on hair was built on low-level laser therapy at 650 to 680nm, not on 660nm plus 850nm LEDs. Caps and helmets place emitters directly on the scalp, at close range, through hair, which is the only sensible geometry for the target.
Intensity here is strikingly low. The helmet in Yoon and colleagues' sham-controlled trial in Medicine (Baltimore) in 2020 measured 2.56 mW/cm2, was worn 25 minutes every other day, and still produced a 41.90 hairs per square centimeter density gain against 0.72 in the sham group.
Cap versus comb is a coverage question. Jimenez and colleagues' 269-person trial in the American Journal of Clinical Dermatology in 2014 used lasercombs passed over the scalp three times a week for 26 weeks and did show terminal hair count gains. A cap that treats the whole scalp hands-free is simply easier to sustain for six months. Hair evidence covers the trials.
Handhelds and wands
Small handhelds are useful for travel and for spot work when you already own something bigger. Battery-powered units in this class have measured irradiance comparable to full panels over their small emitting area.
Wands are the weakest proposition here. A 14-LED wand delivers a fraction of the total energy of a 130 to 236 LED mask, and because you keep moving it, the delivered dose per area is essentially unknowable.
Do not overbuy on intensity
The recurring mistake is assuming that the highest irradiance device is the best device. Photobiomodulation follows a biphasic dose response, described by Huang, Chen, Carroll and Hamblin in Dose Response in 2009: below a threshold nothing happens, and above the useful window the effect declines again.
The mask trial that worked ran at 10 mW/cm2. The hair helmet that worked ran at 2.56 mW/cm2. Intensity buys you shorter sessions, not better outcomes. Dosage has the arithmetic.
A quick decision
Face and skin: mask. Knee, shoulder, elbow or back: contact wrap or a strap-mounted targeted device. Scalp: laser cap or helmet with a documented FDA clearance. Whole body or general recovery: panel. Travel and occasional spot work alongside a main device: handheld.
Note that FDA clearance is specific to a stated use and is not FDA approval. A device cleared for promoting hair growth is not cleared for wrinkles, and clearance says nothing about relative performance. Safety explains the distinction.
FAQ
Can I use a panel on my face instead of buying a mask? You can, and people do. You will need to hold a fixed distance and position, and you will light one plane of your face at a time. A mask delivers a more even dose with less effort, which matters mainly because it makes twelve weeks of adherence realistic.
Is a big panel a waste if I only care about one knee? Mostly, yes. Buy a wrap. A panel treats a knee poorly compared with a device that touches it, regardless of the panel's spec sheet.
Do I need both a panel and a targeted device? Only if you have both a whole-body goal and a specific problem area. Most people have one of the two and buy for both, which is how a lot of unused hardware ends up in closets.
Does a mask work for the neck and chest? Not unless it is designed to. Face masks are shaped for the face, and separate neck and chest devices exist for that reason. Check the coverage area before assuming.
Sources
- Park SH, Park SO, Jung JA. Clinical study to evaluate the efficacy and safety of home-used LED and IRED mask for crow's feet: a multi-center, randomized, double-blind, sham-controlled study. Medicine (Baltimore). 2025;104(7):e41596. https://pmc.ncbi.nlm.nih.gov/articles/PMC11835066/
- Wunsch A, Matuschka K. A Controlled Trial to Determine the Efficacy of Red and Near-Infrared Light Treatment in Patient Satisfaction, Reduction of Fine Lines, Wrinkles, Skin Roughness, and Intradermal Collagen Density Increase. Photomedicine and Laser Surgery. 2014;32(2):93-100. https://journals.sagepub.com/doi/10.1089/pho.2013.3616
- Stausholm MB, et al. Efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials. BMJ Open. 2019;9(10):e031142. https://pubmed.ncbi.nlm.nih.gov/31662383/
- Yoon JS, Ku WY, Lee JH, Ahn HC. Low-level light therapy using a helmet-type device for the treatment of androgenetic alopecia: a 16-week, multicenter, randomized, double-blind, sham device-controlled trial. Medicine (Baltimore). 2020;99(29):e21181. https://pmc.ncbi.nlm.nih.gov/articles/PMC7373546/
- Jimenez JJ, et al. Efficacy and safety of a low-level laser device in the treatment of male and female pattern hair loss: a multicenter, randomized, sham device-controlled, double-blind study. American Journal of Clinical Dermatology. 2014;15(2):115-127. https://www.dermatologytimes.com/view/research-and-evidence-in-home-hair-therapies
- Huang YY, Chen AC, Carroll JD, Hamblin MR. Biphasic Dose Response in Low Level Light Therapy. Dose Response. 2009;7(4):358-383. https://pubmed.ncbi.nlm.nih.gov/20011653/