Use

Huge search demand, thin evidence — Cochrane's review of 17 trials found no clear benefit for eye strain and an inconclusive one for sleep.

Cold water immersion has decent evidence for reducing post-exercise soreness and inflammation, but the hype often outpaces what the science actually supports.

A skin patch that tracks blood sugar every few minutes — genuinely useful for people with diabetes, but for everyone else the readings don't reliably track HbA1c and the behavior-change payoff is unproven.

Active mattress cooling is the rare device with an independent RCT behind it — but the win shows up in how rested you feel, not in objective sleep-stage data.

A conductive mat that connects you to a wall outlet's ground pin, marketed as replicating the health benefits of walking barefoot outdoors — the research is thin and almost entirely produced by the company that sells the theory.

HEPA air purifiers are a well-established, evidence-backed tool for reducing airborne allergens and particulate matter indoors — direct relief of allergy and asthma symptoms is plausible but less consistently supported.

Real-time heart-rate-variability training for slow breathing — a solid, reproducible signal for anxiety and stress, but a thin and inconsistent case for broader cardiovascular claims.

Infrared saunas show meaningful cardiovascular and recovery benefits, but detoxification and skin-health claims remain unproven by direct evidence.

Red light therapy (photobiomodulation) has growing RCT support for skin health and exercise recovery, though optimal protocols are still being defined.

Ring and wrist trackers are reasonably accurate at detecting whether you're asleep, mediocre at detecting which sleep stage you're in, and unproven as a way to actually improve your sleep.

Sit-stand desks reliably cut sedentary time and produce small, real improvements in glucose and body-fat markers — reductions in heart attacks or death haven't been shown, because no trial has run long enough or been large enough to look.

The marquee claim — that it protects bone during weight loss — was debunked by the largest trial to date; it may still add useful training load.